Intracardiac ablation of interventricular septum and associated devices, systems, and methods

Abstract

An apparatus includes a flexible elongate member configured to be advanced through a blood vessel and positioned inside the heart of a patient. The apparatus also includes at least one expandable member coupled to a distal portion of the flexible elongate member, and a plurality of electrodes coupled to the at least one expandable member. When the at least one expandable member is in an expanded configuration, the at least one expandable member is configured to bring the plurality of electrodes into contact with an interventricular septum of the hear. When the plurality of electrodes is in contact with the interventricular septum, the plurality of electrodes is configured to deliver electrical energy to the interventricular septum to reduce a volume of the interventricular septum.

Description

INTRACARDIAC ABLATION OF INTERVENTRICULAR SEPTUM AND ASSOCIATED DEVICES, SYSTEMS, AND METHODSFIELD

[0001] The subject matter described herein relates to systems, devices, and methods for reducing the size (e.g., volume, area) of the heart’s interventricular septum using electrodebased intracardiac ablation. This interventricular septum ablation system has particular but not exclusive utility for addressing left ventricular outflow tract occlusions (e.g., in valve replacement procedures) and / or treating hypertrophic cardiomyopathy.BACKGROUND

[0002] Of patients who need a replacement for a diseased mitral valve, a substantial number also have anatomy that does not allow for an adequate cross-sectional area for the left ventricular outflow tract (e.g., the space between the device to be implanted and the septum, which divides the left and right portions of the heart). This can cause a restriction in the blood flow out of the aortic valve which is adjacent to the mitral valve.

[0003] In the past, there have been methods to increase the cross-sectional area of the left ventricular outflow tract. First, if open heart surgery is indicated, the surgeon will either make a slit in the septal tissue from just under the aortic valve down the left ventricle, causing the cut to splay open, or, in more modem techniques, the surgeon will remove a “v” shaped piece of septal tissue along the same trajectory as the cut mentioned above. This procedure is only an option for those patients receiving an open surgically implanted valve.

[0004] For those patients who are going to receive an endovascularly implanted valve, one option is an alcohol ablation of the septal tissue, which involves gaining catheter access to the coronary arteries, sub-selecting one that supplies the appropriate area of the septum with blood, and then injecting around 2 cc of alcohol to cause necrosis of the septal tissue in the vicinity of the vessel into which the alcohol is injected. However, because necrosis actually kills tissue cells of the septum, some loss of integrity of the septum may occur. Necrosis can also lead to swelling and edema, which are contraindicated for the valve replacement procedure. The alcohol can also affect surrounding vascular and nerve cells in undesirable ways, with potentially unpredictable results.

[0005] Another option for endovascular implant patients is the SESAME procedure, which involves guiding a wire into the septal wall, and advancing it down towards the apexof the heart and back into the left ventricle. Once the wire exits the septum, it is snared, and both ends are externalized. RF energy is then applied to the wire to cut a slit in the septum that mimics the open surgical technique described above. However, this procedure is complex and time-consuming, and requires a high degree of skill and training on the part of the surgeon.

[0006] It is to therefore be appreciated that existing procedures have numerous drawbacks, including complexity, tissue damage, limitation to open-heart procedures, and otherwise.

[0007] The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded as subject matter by which the scope of the disclosure is to be bound.SUMMARY

[0008] An interventricular septum ablation system is disclosed that makes endovascular septum volume reduction faster, more predictable, and less technically challenging, by using pulsed field ablation (PF A) on myocardial tissue. PFA causes electroporation of the myocardial cells, leading to apoptotic death of those cells, while essentially preserving the surrounding vascular and nerve cells. The interventricular septum ablation system includes a pulsed field generator that provides a pulsed electric field with an amplitude, frequency, and / or pulse duration(s) suitable for reducing the volume of the interventricular septum. The interventricular septum ablation system also includes a balloon catheter, steerable catheter, or a retrievable stent that incorporates electrodes capable of contacting the septal myocardial tissue and delivering the pulsed field energy. The interventricular septum ablation system disclosed herein has particular, but not exclusive, utility for addressing left ventricular outflow tract occlusions (e.g., in valve replacement procedures) and / or treating hypertrophic cardiomyopathy.

[0009] One general aspect includes an apparatus. The apparatus includes a flexible elongate member configured to be advanced through a blood vessel and positioned inside of a heart of a patient; at least one expandable member coupled to a distal portion of the flexible elongate member; and a plurality of electrodes coupled to the at least one expandable member, where, when the at least one expandable member includes an expanded configuration, the at least one expandable member is configured to bring the plurality of electrodes into contact with an interventricular septum of the heart, where, when the plurality of electrodes is in contact with the interventricular septum, the plurality of electrodes is configured to deliver electrical energy to the interventricular septum to reduce a volume of the interventricular septum.

[0010] Implementations may include one or more of the following features. In some aspects, the flexible elongate member may include a catheter, where the at least one expandable member may include at least one balloon. In some aspects, the apparatus may include one or more inflation fluid sources configured to inflate the at least one balloon. In some aspects, the one or more inflation fluid sources may include a syringe or an endoflator. In some aspects, the at least one balloon may include at least one of a non-compliant balloon or a compliant balloon. In some aspects, the at least one balloon may include a non- compliant balloon and a compliant balloon, where the plurality of electrodes is coupled to the compliant balloon. In some aspects, the apparatus may include a flexible substrate coupled tothe compliant balloon and the plurality of electrodes. In some aspects, when the non- compliant balloon is in the expanded configuration, the non-compliant balloon is configured to contact tissue of the heart such that the flexible elongate member is stationary relative to the heart, and when the compliant balloon is in the expanded configuration, the compliant balloon is configured to cause the plurality of electrodes to conform to a shape of the interventricular septum. In some aspects, the non-compliant balloon is centered relative to the flexible elongate member, and the compliant balloon is laterally offset relative to the flexible elongate member.

[0011] In some aspects, the electrical energy delivered by the plurality of electrodes may include pulsed field ablation. In some aspects, the flexible elongate member may include a push wire, and the at least one expandable member may include a retrievable stent coupled to a distal portion of the push wire. In some aspects, the at least one expandable member may include a compliant balloon coupled to the retrievable stent, where the plurality of electrodes is coupled to the compliant balloon. In some aspects, the apparatus may include a flexible substrate coupled to the compliant balloon and the plurality of electrodes. In some aspects, when the retrievable stent is in the expanded configuration, the retrievable stent is configured to contact tissue of the heart such that the flexible elongate member is stationary relative to the heart, and where, when the compliant balloon is in the expanded configuration, the compliant balloon is configured to cause the plurality of electrodes to conform to a shape of the interventricular septum. In some aspects, the apparatus may include the pulsed field generator. In some aspects, the inflation lumen and the plurality of the electrical lines are received within the retention tube such that the retention tube is configured to allow relative longitudinal movement between: the retention tube; and the inflation lumen and the plurality of the electrical lines. In some aspects, the retrievable stent, the compliant balloon, and the plurality of electrodes are coupled only at a distal portion of the retrievable stent, where the retrievable stent is configured to have a change in length during a transition from an unexpanded configuration to the expanded configuration, and where the change in length is configured to cause the relative longitudinal movement between: the retention tube; and the inflation lumen and the plurality of the electrical lines. In some aspects, the at least one expandable member may include a temporary valve configured to allow blood flow in a first direction and to prevent the blood flow in a second, opposite direction. In some aspects, the processor is configured to activate the pulsed field generator to output the electrical energy to the plurality of electrodes such that the plurality of electrodes provide pulsed field ablation to the interventricular septum to trigger apoptosis in cells of the interventricular septum.Implementations of the described techniques may include hardware, a method or process, or computer software on a computer-accessible medium.

[0012] One general aspect includes an apparatus with a catheter configured to reduce a volume of the interventricular septum. The apparatus may include: a flexible elongate member configured to be advanced through a blood vessel and positioned inside of a heart of a patient; a plurality of electrodes positioned at a distal portion of the flexible elongate member; a pullwire configured to deflect the distal portion of the flexible elongate member relative to a proximal portion of the flexible elongate member and bring the plurality of electrodes into contact with the interventricular septum of the heart, where, when the plurality of electrodes is in contact with the interventricular septum, the plurality of electrodes is configured to deliver pulsed field ablation to the interventricular septum.

[0013] One general aspect includes a system. The system includes a processor configured for communication with a pulsed field generator; and a pulsed field ablation catheter that may include a plurality of electrodes configured for communication with the pulsed field generator and to contact vascular tissue, where the processor is configured to activate the pulsed field generator to output electrical energy to the plurality of electrodes such that the plurality of electrodes provide pulsed field ablation to the vascular tissue to trigger apoptosis in cells of the vascular tissue and reduce a volume of the vascular tissue.

[0014] One general aspect includes a method for reducing the volume of vascular tissue. The method includes: providing a pulsed field generator configured to trigger apoptosis in cells of tissue; providing a processor configured to control the pulsed field generator; providing a flexible elongate member; positioning a plurality of electrodes a distal portion of the flexible elongate member and electrically coupling the plurality of electrodes to the pulsed field generator; and providing a presser configured to press the electrodes against the tissue. When the electrodes are pressed against the tissue, activation of the pulsed field generator triggers the apoptosis in the cells of the tissue.

[0015] One general aspect includes a system for reducing the volume of vascular tissue. The system includes: a pulsed field generator configured to trigger apoptosis in cells of tissue; a processor configured to control the pulsed field generator; a flexible elongate member; a plurality of electrodes positioned at a distal portion of the flexible elongate member and electrically coupled to the pulsed field generator; and a presser configured to press the electrodes against the tissue. When the electrodes are pressed against the tissue, activation of the pulsed field generator triggers the apoptosis in the cells of the tissue. The pulsed field generator is configured to trigger apoptosis in myocardial cells of aninterventricular septum of a heart or osteocyte cells of a calcification, and is configured to not trigger apoptosis in vascular smooth muscle tissue or nerve tissue. The presser includes a non-compliant balloon and a compliant balloon.

[0016] Implementations may include one or more of the following features. In some aspects, the system may include the pulsed field generator. In some aspects, the vascular tissue may include an interventricular septum of a heart, where the pulsed field ablation is configured to trigger the apoptosis in myocardial cells of the interventricular septum and not in vascular smooth muscle tissue or nerve tissue. In some aspects, the pulsed field ablation is configured to trigger apoptosis in osteocyte cells of a calcification and not in vascular smooth muscle tissue or nerve tissue. In some aspects, the system may include one or more inflation fluid sources configured to inflate the one or more balloons. In some aspects, the pulsed field ablation catheter further may include one or more balloons, where, when inflated, the one or more balloons are configured to bring the plurality of electrodes into contact with the vascular tissue. In some aspects, the one or more inflation fluid sources may include a syringe or an endoflator. In some aspects, the pulsed field ablation catheter further comprises an expandable stent and a balloon, where, when the expandable stent is expanded and the balloon is inflated, the expandable stent and the balloon are configured to bring the plurality of electrodes into contact with the vascular tissue. In some aspects, the system further includes a temporary valve configured to allow blood to flow through a portion of the pulsed field ablation catheter in a first direction and to prevent blood from flowing in a second, opposite direction.

[0017] A system of one or more computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions. Aspects can include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

[0018] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. A more extensive presentation of features, details, utilities, and advantages of the interventricular septum ablation system, asdefined in the claims, is provided in the following written description of various aspects of the disclosure and illustrated in the accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Illustrative aspects of the present disclosure will be described with reference to the accompanying drawings, of which:

[0020] Figure 1A is a front view of a human heart according to aspects of the present disclosure.

[0021] Figure IB is a cross-sectional front view of a human heart according to aspects of the present disclosure.

[0022] Figure 2 is a schematic, diagrammatic view, in block diagram form, of a system according to aspects of the present disclosure.

[0023] Figure 3 is a schematic, diagrammatic side view of an example pulsed field ablation catheter, according to aspects of the present disclosure.

[0024] Figure 4A is an enlarged view of the distal portion of the pulsed field ablation catheter of Figure 3, according to aspects of the present disclosure.

[0025] Figure 4B is a lateral cross-sectional view of the distal portion of the pulsed field ablation catheter of Figure 4 along cross-section line 4B-4B in the unexpanded or uninflated state, according to aspects of the present disclosure.

[0026] Figure 5A is an enlarged view of the distal portion of the pulsed field ablation catheter of Figure 3, wherein both the non-compliant balloon and the compliant balloon are in the inflated or expanded state, according to aspects of the present disclosure.

[0027] Figure 5B is a lateral cross-sectional view of the distal portion of the pulsed field ablation catheter of Figure 5 along cross-section line 5B-5B in the expanded or inflated state, according to aspects of the present disclosure.

[0028] Figure 6 is a lateral cross-sectional view of the pulsed field ablation catheter of Figure 4A along cut line 6-6, according to aspects of the present disclosure.

[0029] Figure 7 is a front cross-sectional view of the heart with a pulsed field ablation catheter positioned within the aortic valve and left ventricular outflow tract, according to aspects of the present disclosure.

[0030] Figure 8 is an enlarged view of the distal portion of the pulsed field ablation catheter of Figure 3, wherein both the non-compliant balloon and the compliant balloon are in the inflated or expanded state, according to aspects of the present disclosure.

[0031] Figure 9 is a schematic, diagrammatic representation, in flow diagram form, of an example pulsed field interventricular septum ablation method, according to aspects of the present disclosure.

[0032] Figure 10 is a schematic, diagrammatic view, in block diagram form, of a system, according to aspects of the present disclosure.

[0033] Figure 11 is a schematic, diagrammatic side view of an example pulsed field ablation catheter, according to aspects of the present disclosure.

[0034] Figure 12 is a lateral cross-sectional view of the pulsed field ablation catheter of Figure 11 along cut line 12-12, according to aspects of the present disclosure.

[0035] Figure 13 is a front cross-sectional view of the heart with a pulsed field ablation catheter positioned within the aortic valve and left ventricular outflow tract, according to aspects of the present disclosure.

[0036] Figure 14 is a schematic diagram of a processor circuit, according to aspects of the present disclosure.

[0037] Figure 15 is an enlarged view of the distal portion of the pulsed field ablation catheter (e.g., of Figure 7), according to aspects of the present disclosure.

[0038] Figure 16 is a schematic, diagrammatic view, in block diagram form, of a system according to aspects of the present disclosure.

[0039] Figure 17 is an enlarged view of the distal portion of the pulsed field ablation catheter of Figure 15, according to aspects of the present disclosure.

[0040] Figure 18A is a lateral cross-sectional view of the distal portion of the pulsed field ablation catheter of Figure 15 along cross-section line 17-17, in the expanded or inflated state, according to aspects of the present disclosure.

[0041] Figure 18B is a lateral cross-sectional view of the distal portion of the pulsed field ablation catheter of Figure 15 along cross-section line 17-17, in the expanded or inflated state, according to aspects of the present disclosure.

[0042] Figure 19 is a schematic, diagrammatic view, in block diagram form, of a system according to aspects of the present disclosure.

[0043] Figure 20 is a schematic, diagrammatic longitudinal cross-sectional side view of an example intracardiac pulsed field ablation device, according to aspects of the present disclosure.

[0044] Figure 21 is an enlarged view of the distal portion of the intracardiac PFA device of Figure 20 in its constrained or unexpanded state, according to aspects of the present disclosure.

[0045] Figure 22 is an enlarged view of the distal portion of the intracardiac PFA device of Figure 20 in its expanded state, according to aspects of the present disclosure.

[0046] Figure 23 is an enlarged view of the distal portion of the intracardiac PFA device in its expanded state, according to aspects of the present disclosure.

[0047] Figure 24 is an enlarged view of the distal portion of the intracardiac PFA device in its expanded state, according to aspects of the present disclosure.

[0048] Figure 25 is a lateral cross-sectional view of at least a portion of the intracardiac PFA device, taken along cut line 25-25 of Figure 22, according to aspects of the present disclosure.

[0049] Figure 26 is a lateral cross-sectional view of at least a portion of the intracardiac PFA device, taken along cut line 26-26 of Figure 23, according to aspects of the present disclosure.

[0050] Figure 27 is an enlarged side view of the distal portion of the intracardiac pulsed field ablation catheter of Figure 23, wherein both the stent and the compliant balloon are in the inflated or expanded state, according to aspects of the present disclosure.

[0051] Figure 28 is an enlarged side view of the distal portion of the intracardiac pulsed field ablation catheter of Figure 24, wherein both the stent and the compliant balloon are in the inflated or expanded state, according to aspects of the present disclosure.

[0052] Figure 29 is a lateral cross-sectional view of the PFA device, in the expanded configuration, taken along cut line 29-29 of Figure 27, according to aspects of the present disclosure.

[0053] Figure 30 is a lateral cross-sectional view of the PFA device, in the expanded configuration, taken along cut line 30-30 of Figure 28, according to aspects of the present disclosure.DETAILED DESCRIPTION

[0054] An interventricular septum ablation system is disclosed. The systems, devices and methods described herein make endovascular septum volume reduction / left ventricular outflow tract expansion much faster and more predictable, as well as less technically challenging, than the SESAME procedure. The interventricular septum ablation system of the present disclosure takes advantage of the mechanism of action of Pulsed Field Ablation (PF A) on myocardial tissue. PFA causes electroporation of the myocardial cells, leading to apoptotic death of those cells, while essentially preserving the surrounding vascular and nerve cells.

[0055] Necrosis can be described as uncontrolled cell death due to injury, toxins, infections, etc., and can cause swelling, edema, and an accumulation of cellular debris that must be removed by the body. Conversely, apoptosis can be described as programmed cell death - a more orderly dismantling process that leaves portions of the cell in place and causes substantially less trauma to surrounding tissue. Apoptosis is known to cause a reduction in the volume of the tissues affected (e.g., an apoptotic volume decrease (AVD) of 50% or more). Thus, by applying a pulsed electric field to septal tissue, the interventricular septum ablation system shrinks septal tissue and consequently causes an increase in the left ventricular outflow tract cross sectional area.

[0056] The methods disclosed herein may be less technically challenging, much faster, and more controlled than the other endovascular outflow tract expansion options described above.

[0057] An interventricular septum ablation system includes a pulsed field generator, energy that is applied by the pulsed field generator, and a catheter to deliver the energy to the tissue. The pulsed field generator described herein operates at a lower energy (e.g., a higher voltage but a much lower current) compared to a radio frequency generator used for electrosurgery. The pulsed field generator may, for example, be a Boston Scientific Farapulse, a Medtronic PulseSelect, or other pulsed field generator capable of generating electrical pulses at the amplitudes (e.g., voltages), frequencies, and pulse durations described herein. Farapulse and PulseSelect are used for disrupting electrical signals in the heart muscle for atrial fibrillation treatment, not to reduce the volume of the heart tissue (as described herein).

[0058] The energy outputted / provided by the pulsed field generator is suitable for decreasing the volume of tissue. For example, the amplitude, frequency, and / or pulseduration(s) are selected for the outflow tract expansion procedure described herein. The values of the amplitude, frequency, and / or pulse duration(s) for the outflow tract expansion procedure can be different than those for, e.g., atrial fibrillation treatments.

[0059] The system uses a balloon catheter incorporating electrodes as described below. The catheter described herein described herein a substantially different catheter compared to the atrial fibrillation treatment devices. In other aspects, the catheter for the interventricular septum ablation system may be a steerable ablation catheter, with electrodes provided directly or indirectly on the surface of the catheter (e.g., without using balloons). In other aspects, a retrievable stent incorporating electrodes can be used to perform the ablation.

[0060] To perform the outflow tract expansion procedure, the clinician advances the guidewire through vasculature (e.g., blood vessels) inside the patient’s body, to the aortic valve, and across the aortic valve. Once this is done, the outflow tract expansion catheter is advanced, over the wire, through the vasculature (e.g., blood vessels) inside the patient’s body, to the aortic valve, and across the aortic valve. In other instances, a guide catheter can be introduced over the wire and the guidewire removed, such that the outflow tract expansion catheter is advanced inside the guide catheter. The outflow tract expansion catheter may for example have two balloons and a multitude of electrodes incorporated into it, where one balloon is non-compliant and concentric to the guidewire. This balloon, when inflated, provides a structure for the second, compliant balloon to oppose against in order to bring the electrodes into contact with the septal tissue to be ablated. The catheter can be rotated until the electrodes are adjacent to the septal wall. Once the non-compliant balloon is inflated, the compliant balloon is inflated to low pressure to bring the electrodes into contact with the septal wall. Once proper arrangement of the device is verified (e.g., by fluoroscopy and / or ultrasound imaging), the electrodes are energized, in pairs, with high voltage (e.g., 250-500 volts per centimeter) at high frequencies (e.g., 1 kHz - 10 kHz and short pulse widths (e.g., 100 microseconds to 1000 milliseconds, a non-zero amount that is less than one second) to cause electroporation of the myocardial cells and thus trigger apoptosis. There can be several pairs of electrodes on an ablation catheter. The voltage between adjacent electrodes alternates, so that the voltage flux (e.g., in volts / cm) is optimized by keeping the distance between electrode pairs small. This electroporation process can take as little as one second and as long as several seconds. Because vascular smooth muscle tissue and nerve tissue require higher field strengths to trigger electroporation (e.g., 1750 and 3800 V / cm, respectively), these tissues may be largely unaffected by the PFA treatment. Cell death via apoptosis can take anywhere from several hours to one day to complete. Thus, the outflowtract expansion procedure may be performed in conjunction with another procedure, or may be completed in a prior procedure to a valve replacement.

[0061] Depending on the implementation, the electrodes may be on a separate structure attached to the compliant balloon, or may be on the compliant balloon’s surface (e.g., printed or plated directly onto the compliant balloon’s surface).

[0062] The present disclosure aids substantially in increasing the volume of the left ventricular outflow tract, by improving a clinician’s ability to ablate septal myocardial tissue with little or no damage to surrounding vascular and nerve tissue. Implemented on an intravascular catheter in communication with a pulsed field generator and amplifier, the interventricular septum ablation system disclosed herein provides practical improvements in surgery times and outcomes. This improved surgical process transforms an oversized heart septum into one with reduced volume, without the normally routine need to cut in incision into the septum or poison it with alcohol. This unconventional approach improves the functioning of the heart, by decreasing the volume of the septum and thus increasing the volume of the left ventricular outflow tract.

[0063] The interventricular septum ablation system may incorporate a process at least partially viewable on a display, and operated by a control process executing on a processor that accepts user inputs from a keyboard, mouse, or touchscreen interface, and that is in communication with a pulse generator and two or more electrodes. In that regard, the control process performs certain specific operations in response to different inputs or selections made at different times. Certain outputs of the interventricular septum ablation system may be printed, shown on a display, or otherwise communicated to human operators. Certain structures, functions, and operations of the processor, display, sensors, and user input systems are known in the art, while others are recited herein to enable novel features or aspects of the present disclosure with particularity.

[0064] These descriptions are provided for exemplary purposes only, and should not be considered to limit the scope of the interventricular septum ablation system. Certain features may be added, removed, or modified without departing from the spirit of the claimed subject matter.

[0065] For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the aspects illustrated in the drawings, and specific language will be used to describe the same. It is nevertheless understood that no limitation to the scope of the disclosure is intended. Any alterations and further modifications to the described devices, systems, and methods, and any further application of the principles of thepresent disclosure are fully contemplated and included within the present disclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and / or steps described with respect to one aspect may be combined with the features, components, and / or steps described with respect to other aspects of the present disclosure. For the sake of brevity, however, the numerous iterations of these combinations will not be described separately.

[0066] Figure 1A is a front view of a human heart 100 according to aspects of the present disclosure. Visible are an aorta 102 from which stems a right coronary artery 104 and a left main coronary artery 106. The left main coronary artery 106 branches into a left circumflex coronary artery 108 and a left anterior descending coronary artery 110. The right coronary artery 104, the left main coronary artery 106, the left circumflex coronary artery 108, and a left anterior descending coronary artery 110 are the arteries that provide oxygen-rich blood to muscles of the human heart 100.

[0067] Figure IB is a cross-sectional front view of a human heart 100 according to aspects of the present disclosure. Visible are a right atrium 112 and a right ventricle 114. In that regard, oxygen-poor blood enters the human heart 100 in the right atrium 112 and travels to the right ventricle 114 through the tricuspid valve 116. The oxygen-poor blood leaves the right ventricle 114 and travels to the lungs. Also visible are a left atrium 118 and a left ventricle 120. In that regard, oxygen-rich blood is received from the lungs in the left atrium 118 and travels to the left ventricle 120 through the mitral valve 122. The oxygen-rich blood leaves the left ventricle 120 and goes out to the body through the aorta 102 via an aortic valve 124.

[0068] The septum 130 separates the left ventricle 120 from the right ventricle 114. If the septum 130 is thickened (e.g., due to disease or natural anatomical variation between individuals), then the left ventricular outflow tract or LVOT 140 will have a reduced volume, which can interfere with the flow of blood through the mitral valve 122 and / or aortic valve 124. In some aspects, this can be described as left ventricular outflow tract obstruction (LVOTO). For example, the context can be a valve replacement procedure, such as when the replacement valve physically contacts the enlarged septum in a way that is undesirable (e.g., preventing positioning and / or expansion of the replacement valve, without risk of harm to the patient). In some aspects, this can be described as hypertrophic cardiomyopathy. It is desirable to reduce the volume of a thickened septum 130 in order to increase the volume of the left ventricular outflow tract or LVOT 140. This can be related to valve replacement procedures (e.g., ensure proper positioning and / or deployment of replacement valves in mitralvalve replacement procedure or aortic valve replacement procedure) or separate from valve replacement procedures (e.g., treatment for hypertrophic cardiomyopathy).

[0069] Before continuing, it should be noted that the examples described above are provided for purposes of illustration, and are not intended to be limiting. Other devices and / or device configurations may be utilized to carry out the operations described herein.

[0070] Figure l is a schematic, diagrammatic view, in block diagram form, of a system 200 according to aspects of the present disclosure. The system 200 may be configured to control (e.g., modify) one or more aspects of a cardiac valve replacement procedure. For instance, the system 200 may be utilized to reduce the volume of the interventricular septum of the heart and thus increase the volume and / or area (e.g., surface area, cross-sectional area) of the left ventricular outflow tract, as described in greater detail below. In this regard, the system 200 may be used to modify coronary vessels and / or heart tissue (e.g., the myocardium). As illustrated, the system 200 may include a console 202 that includes a processor 210 in communication with a memory 205, display device 220 (e.g., an electronic display or monitor), an input device 230 (e.g., a user input device, such as a keyboard, mouse, joystick, microphone, and / or other controller or input device), a pulsed field generator 240, and a pulsed field ablation catheter 250.

[0071] The pulsed field ablation catheter 250 is guided into the heart over a guidewire 260. The pulsed field ablation catheter 250 includes a flexible elongate member 252 as well as electrodes 254 that are energized by the pulsed field generator 240. The pulsed field ablation catheter 250 may also include a non-compliant balloon 256 that can be inflated by an inflation fluid source 270, and a compliant balloon 258 that can be inflated by an inflation fluid source 280. The inflation fluid sources 270, 280 may be endoflators, syringes, pumps, etc.

[0072] The processor 210 is generally representative of any device suitable for performing the processing and analysis techniques disclosed herein. In some aspects, the processor 210 includes a processor circuit, such as the processor circuit 1400 of Figure 14. In some aspects, the processor 210 is programmed to execute steps associated with the data acquisition, analysis, and / or instrument (e.g., device) control described herein. Accordingly, it is understood that any steps related to data acquisition, data processing, instrument control, and / or other processing or control aspects of the present disclosure may be implemented by the processor 210 (e.g., computing device) using corresponding instructions stored on or in a non-transitory computer readable medium accessible by the computing device. Further, it is understood that in some instances the processor 210 includes one or a plurality of computingdevices, such as computers, with one or a plurality of processor circuits. In this regard, it is particularly understood that the different processing and / or control aspects of the present disclosure may be implemented separately or within predefined groupings using a plurality of computing devices. Any divisions and / or combinations of the processing and / or control aspects described below across multiple computing devices are within the scope of the present disclosure.

[0073] It is noted that block diagrams are provided herein for exemplary purposes; a person of ordinary skill in the art will recognize myriad variations that nonetheless fall within the scope of the present disclosure. For example, block diagrams may show a particular arrangement of components, subcomponents, modules, units, etc. It is understood that some embodiments of the systems disclosed herein may include additional components, that some components shown may be absent from some embodiments, and that the arrangement of components may be different than shown, while still performing the methods described herein.

[0074] Figure 3 is a schematic, diagrammatic side view of an example pulsed field ablation catheter 250, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, electrodes 254, non-compliant balloon 256, and compliant balloon 258. The flexible elongate member 252 can be a catheter body made from a polymer or a plastic that is flexible to traverse vasculature of the patient (which can be tortuous). Also visible is a connector 310 that includes a non-compliant balloon full port 320 to which the non-compliant balloon inflation fluid source 270 can be attached, and a compliant balloon fill port 330 to which the compliant balloon inflation fluid source 280 can be attached (see Fig. 2). The connector 310 also includes an electrical connector 340 to which a cable 350 attaches, to provide electrical energy to the electrodes 254. The cable 350 also attaches to a console connector 360 that connects to the console 202 and / or to the pulsed field generator 240 (see Figure 2).

[0075] In the example shown in Figure 3, the non-compliant balloon 256 and the compliant balloon 258 are in the deflated or non-expanded state. When the non-compliant balloon 256 and the compliant balloon 258 are in the deflated or non-expanded state, the pulsed field ablation catheter 250 is sized and shaped for insertion into the heart through the vasculature of the body. When the non-compliant balloon 256 and the compliant balloon 258 are in the inflated or expanded state, the pulsed field ablation catheter 250 is configured to deliver treatment (e.g., pulsed field ablation therapy) to the interventricular septum. Thedistal portion 370 of the pulsed field ablation catheter 250 is shown below in greater detail in Figure 4A.

[0076] Figure 4A is an enlarged view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 3, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, electrodes 254, non-compliant balloon 256, and compliant balloon 258. Also visible is a flexible or compliant substrate 410 which supports the electrodes 254. The electrodes may for example be coated, printed, or attached to the substrate 410.

[0077] In the example shown in Figure 4A, both the non-compliant balloon 256 and the compliant balloon 258 are in the uninflated or unexpanded state

[0078] The non-compliant balloon 256 may be directly coupled to flexible elongate member 252, whether by adhesive, heat welding, or other coupling, or may be formed as part of the flexible elongate member 252. The non-compliant balloon 256 may be directly coupled to compliant balloon 258, whether by adhesive, heat welding, or other coupling. In some aspects, the compliant balloon 258 could be directly coupled to flexible elongate member 252, whether by adhesive, heat welding, or other coupling, or may be formed as part of the flexible elongate member 252. The compliant balloon 258 may be directly coupled to the flexible substrate 410 carrying the electrodes 254, whether by adhesive, heat welding, or other coupling. In some aspects, the flexible substrate 410 may not be present, and the electrodes 254 may be coupled directly to the surface of the compliant balloon 258. For example, the electrodes 254 may be coated, printed, or attached to the compliant balloon 258 such that they match the curvature of the compliant balloon 258.

[0079] More generally, the PFA catheter 250 includes one or multiple compliant balloons 258 and / or one or multiple non-compliant balloons 256. In some aspects, the PFA catheter 250 includes both the compliant balloon 258 and the non-compliant balloon 256. As shown in Fig. 4A, the electrodes 254 can be coupled to the compliant balloon 258 and not to the non-compliant balloon 256. In some aspects, the PFA catheter 250 includes the compliant balloon 258 and not the non-compliant balloon 256. For example, the electrodes 254 and / or flexible substrate 410 can be coupled to the compliant balloon 258. In some aspects, the PFA catheter includes the non-compliant balloon 256 and not the compliant balloon 258. In such aspects, the electrodes 254 and / or the flexible substrate 410 can be coupled to the non- compliant balloon 256.

[0080] The non-compliant balloon may for example be made from a polymer or plastic, such as PET or Nylon. The compliant balloon may for example be made from a differentpolymer or a different plastic. In some instances, compliant balloon may for example made from urethane or silicone. The flexible substrate may for example be made polymer or plastic, nylon, Pebax, or polyolefin. The electrodes may for example be made of metal or metal alloy, such as platinum, platinum / iridium, gold, etc. Other materials may be used instead or in addition to those listed here.

[0081] The compliant balloon 258 can be coupled to the non-compliant balloon 256, and the non-compliant balloon 256 can be coupled to the flexible elongate member 252. In some aspects, the compliant balloon 258 can be coupled to the non-compliant balloon 256 and not the flexible elongate member 252. In some aspects, the compliant balloon 258 can be coupled to both the non-compliant balloon 256 and the flexible elongate member 252. The flexible substrate 410, and the flexible electrodes formed thereon, may match the curvature of the compliant balloon in both the expanded and unexpanded states.

[0082] Figure 4B is a lateral cross-sectional view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 4 along cross-section line 4B-4B in the unexpanded or uninflated state, according to aspects of the present disclosure. Visible are the flexible elongate member 252, and the guidewire 260, which is positioned within a guidewire lumen 420. Also visible are the non-compliant balloon 256, compliant balloon 258, flexible substrate 410, and an electrode 254. In the example shown in Figure 4B, the non-compliant balloon 256 is centered with respect to the flexible elongate member 252, whereas the compliant balloon 258 is laterally or radially offset relative to the flexible elongate member 252. The inflated state for the non-compliant balloon 256 and the compliant balloon 258 is shown below in Figure 5B.

[0083] Figure 5A is an enlarged view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 3, wherein both the non-compliant balloon 256 and the compliant balloon 258 are in the inflated or expanded state, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, flexible substrate 410, electrodes 254, non-compliant balloon 256, and compliant balloon 258. In the example shown in Figure 5A, the non-compliant balloon 256 is filled with a first inflation fluid 510, and the compliant balloon 258 is filled with a second inflation fluid 520.Depending on the implementation, the first inflation fluid and the second inflation fluid may be the same or different from one another.

[0084] Also visible is heart tissue, including the interventricular septum 130 and the LVOT wall 530 (which is part of the annulus of the aortic valve 124 - see Figure IB). In practice, the pulsed field ablation catheter 250 is maneuvered into the LVOT, and the non-compliant balloon 256 is inflated with the inflation fluid 256 in order to maintain the positioning of the PFA catheter 250 within the aortic valve 124, which also props open the aortic valve 124 (see Figures IB and 7). Depending on the implementation, the heart may be rapid-cycled or rapid-paced during this process to reduce the pressure gradient across the aortic valve, so that it doesn’t push the balloon out of place during the heart cycle. Rapidpacing need not be performed when the PFA catheter 250 includes the temporary valve 1610 (as described with respect to, e.g., Figs. 15-18B). Next, the PFA catheter 250 is rotated until the electrodes 254 are aligned with the interventricular septum 130, and the compliant balloon 258 is inflated with the inflation fluid 520, such that the flexible substrate 410 and the electrodes 254 are pressed against, and comply with the contours of, the septum 130. Next, the electrodes are activated in pulses as described above (e.g., for a period of between 1 second and 5 seconds), such that the pulsed electric field delivers electrical energy to the septum 130 that causes electroporation of cells of the septum 130 that are within a threshold distance of the electrodes (e.g., a given field strength). This electroporation in turn triggers the start of apoptosis or programmed cell death for at least some of the affected cells. This apoptosis (which may take up to 24 hours to complete) has the effect of thinning the interventricular septum and thus widening the left ventricular outflow tract, as described in further detail below in Figure 8.

[0085] In some aspects, the balloons and flexible substrate may form a presser mechanism that is configured to press the electrodes against the tissue to be ablated. Other types of presser mechanisms are contemplated. Because the non-compliant balloon 256 does not conform to the contours of tissue against which it is pressed a gap 540 may exist between the balloon 256 and the tissue 530.

[0086] Figure 5B is a lateral cross-sectional view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 5 along cross-section line 5B-5B in the expanded or inflated state, according to aspects of the present disclosure. Visible are the flexible elongate member 252, guidewire 260, guidewire lumen 420, non-compliant balloon 256, inflation fluid 510, compliant balloon 258, inflation fluid 520, flexible substrate 410, and electrode 254. In the inflated state, the non-compliant balloon presses the compliant balloon into the interventricular septum, and the compliant balloon presses the flexible substrate 410 into the septum, such that the electrodes 254 are in contact with the septum. It is noted that pulsed field ablation can be accomplished by electrodes that are not in direct contact with the tissue of the septum, but the required field strengths may be significantly higher. Thus, such aspects are not preferred.

[0087] Figure 6 is a lateral cross-sectional view of the pulsed field ablation catheter 250 of Figure 4 A along cut line 6-6, according to aspects of the present disclosure. Within the flexible elongate member are four lumens 420, 610, 630, and 640. The guidewire lumen 420 allows for passage of the flexible elongate member 252 over the guidewire 260. An electrical wire lumen 610 allows for passage of electrical wires 620 that connect the electrodes 254 to the pulsed field generator 240 (see Figure 2). A first inflation lumen 630 carries inflation fluid 510 to the non-compliant balloon 256, and a second inflation lumen 640 carries inflation fluid 520 to the compliant balloon 258 (see Figure 5B).

[0088] Figure 7 is a front cross-sectional view of the heart 100 with a pulsed field ablation catheter 250 positioned within the aortic valve 124 and left ventricular outflow tract 140, according to aspects of the present disclosure. In the example shown in Figure 7, the non-compliant balloon 256 is in an inflated state, such that motion of the PFA catheter relative to the heart is arrested or minimized, and the compliant balloon 258 is also in the inflated state that conforms to the shape of the interventricular septum 130, such that the flexible substrate 410 and electrodes 254 are pressed against the interventricular septum 130. In this configuration, the PFA catheter 250 can deliver PFA therapy to the septum 130 in order to shrink it and thus widen the LVOT 140, improving blood flow through the LVOT (e.g., in advance of a valve replacement procedure).

[0089] Figure 8 is an enlarged view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 3, wherein both the non-compliant balloon 256 and the compliant balloon 258 are in the inflated or expanded state, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, flexible substrate 410, electrodes 254, non-compliant balloon 256, inflation fluid 510, compliant balloon 258, inflation fluid 520, interventricular septum 130, and LVOT wall 530. In the example shown in Figure 8, the septum 130 has shrunk to a smaller thickness than that shown in Figure 5 A. A dotted line 810 shows the previous dimensions of the septum 130. Figure 8 is shown for illustrative purposes; in reality, the shrinkage of the septum 130 may occur over a period of up to 24 hours following the withdrawal of the pulsed field ablation catheter 250 from the body of the patient.

[0090] Figure 9 is a schematic, diagrammatic representation, in flow diagram form, of an example pulsed field interventricular septum ablation method 900, according to aspects of the present disclosure. It is understood that the steps of method 900 may be performed in a different order than shown in Figure 9, additional steps can be provided before, during, and after the steps, and / or some of the steps described can be replaced or eliminated in otheraspects. One or more of steps of the method 900 can be carried by one or more devices and / or systems described herein, such as components of the interventricular septum ablation system 200, the processor 210, and / or processor circuit 1450.

[0091] In step 910, the method 900 includes positioning the distal end of the guidewire within the left ventricle of the heart. Execution then proceeds to step 920.

[0092] In step 920, the method 900 includes advancing the pulsed field ablation catheter over the guidewire and across the aortic valve. Execution then proceeds to step 930.

[0093] In step 930, the method 900 includes controlling the inflation of the non- compliant balloon such that the distal portion of the pulsed field ablation catheter is relatively stationary relative to the heart. Depending on the implementation, the heart may be rapid- cycled or rapid-paced during this process, in order to reduce the pressure gradient across the aortic valve. Rapid-pacing need not be performed when the PFA catheter 250 includes the temporary valve 1610 (as described with respect to, e.g., Figs. 15-18B). Execution then proceeds to step 940.

[0094] In step 940, the method 900 includes controlling inflation of the compliant balloon such that the electrodes are pressed against the tissue of the interventricular septum.Execution then proceeds to step 950.

[0095] In step 950, the method 900 includes controlling the pulsed activation of the electrodes to cause a pulsed electric field to extend partway into the tissue of the interventricular septum, triggering electroporation and apoptosis of at least some cells in the affected area. Execution then proceeds to step 950.

[0096] In step 960, the method 900 includes performing additional therapy, such as implantation of a replacement heart valve. In some cases, the additional therapy is performed while the PFA ablation catheter remains inside the body, or shortly after it is removed. In other cases, the additional therapy may be performed in a separate procedure, e.g., at least 24 hours after treatment by the PFA catheter. The method 900 is now complete.

[0097] Flow diagrams are provided herein for exemplary purposes; a person of ordinary skill in the art will recognize myriad variations that nonetheless fall within the scope of the present disclosure. The logic of flow diagrams may be shown as sequential. However, similar logic could be parallel, massively parallel, object oriented, real-time, event-driven, cellular automation, or otherwise, while accomplishing the same or similar functions. In order to perform the methods described herein, a processor may divide each of the steps described herein into a plurality of machine instructions, and may execute these instructions at the rate of several hundred, several thousand, several million, or several billion per second,in a single processor or across a plurality of processors. Such rapid execution may be necessary in order to execute the method in real time or near-real time as described herein. For example, the interventricular septum ablation system 200 may be capable of generating pulses as short as 50 microseconds at a frequency as high as 10 kHz.

[0098] Figure 10 is a schematic, diagrammatic view, in block diagram form, of a system 1000, according to aspects of the present disclosure. The system 1000 may be configured to control (e.g., modify) one or more aspects of a cardiac valve replacement procedure. For instance, the system 1000 may be utilized to reduce the volume of the interventricular septum of the heart and thus increase the volume or cross-sectional area of the left ventricular outflow tract, as described in greater detail below. In this regard, the system 200 may be used to modify coronary vessels and / or heart tissue (e.g., the myocardium). As illustrated, the system 200 may include a console 202 that includes a processor 210 in communication with a memory 205, display device 220 (e.g., an electronic display or monitor), an input device 230 (e.g., a user input device, such as a keyboard, mousejoystick, microphone, and / or other controller or input device), a pulsed field generator 240, and a pulsed field ablation catheter 250.

[0099] The pulsed field ablation catheter 1050 is guided into the heart over a guidewire 260. The pulsed field ablation catheter 1050 includes a flexible elongate member 1052 as well as electrodes 1054 that are energized by the pulsed field generator 240. The pulsed field ablation catheter 250 may also include one or more pullwires 1010 that can be used to steer, bend, deflect, or otherwise alter the shape of the flexible elongate member 1052. The pullwire(s) are controlled by one or more actuators 1020, such as wheels, dials, knobs, levers, switches, or otherwise.

[0100] In some aspects, the pull wires may form a presser mechanism that is configured to press the electrodes against the tissue to be ablated. Other types of presser mechanisms are contemplated.

[0101] Figure 11 is a schematic, diagrammatic side view of an example pulsed field ablation catheter 1050, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 1052, and electrodes 1054. Also visible is a connector 310 an electrical connector 340 to which a cable 350 attaches, to provide electrical energy to the electrodes 1054. The cable 350 also attaches to a console connector 360 that connects to the console 202 and / or to the pulsed field generator 240 (see Figure 10).

[0102] In the example shown in Figure 11, the distal portion 1070 of the flexible elongate member 1052 can be deflected when one or more pullwires (shown below in Figure 12) areactuated by the actuator 1020, and the electrodes 1054 are coupled directly to the outer surface of the flexible elongate member 1052. As with the pulsed field ablation catheter 250 of Figure 3, the pulsed field ablation catheter 1050 is configured to deliver treatment (e.g., pulsed field ablation therapy) to the interventricular septum via the electrodes.

[0103] Figure 12 is a lateral cross-sectional view of the pulsed field ablation catheter 1050 of Figure 11 along cut line 12-12, according to aspects of the present disclosure. Within the flexible elongate member are three lumens 420, 610, and 1140. The guidewire lumen 420 allows for passage of the flexible elongate member 252 over the guidewire 260. An electrical wire lumen 610 allows for passage of electrical wires 620 that connect the electrodes 254 to the pulsed field generator 240 (see Figure 10). A pullwire lumen 1140 accommodates a pullwire 1010. Depending on the implementation, a pullwire lumen may accommodate more than one pullwire, or more than one pullwire lumen may exist, each accommodating a single pullwire.

[0104] Figure 13 is a front cross-sectional view of the heart 100 with a pulsed field ablation catheter 1050 positioned within the aortic valve 124 and left ventricular outflow tract 140, according to aspects of the present disclosure. In the example shown in Figure 13, the flexible elongate member 1052 has been bent or deflected (e.g., by one or more pullwires), such that the electrodes 1054 are pressed against the interventricular septum 130. In this configuration, the PFA catheter 1050 can deliver PFA therapy to the septum 130 in order to shrink it and thus widen the LVOT 140, improving blood flow through the LVOT (e.g., in advance of a valve replacement procedure, for treatment of hypertrophic cardiomyopathy, etc.).

[0105] Figure 14 is a schematic diagram of a processor circuit 1450, according to aspects of the present disclosure. The processor circuit 1450 may be implemented in the system 200, the system 1000, the processor 210, or other devices or workstations (e.g., third-party workstations, network routers, etc.), or on a cloud processor or other remote processing unit, as necessary to implement the method. As shown, the processor circuit 1450 may include a processor 1460, a memory 1464, and a communication module 1468. These elements may be in direct or indirect communication with each other, for example via one or more buses.

[0106] The processor 1460 may include a central processing unit (CPU), a digital signal processor (DSP), an ASIC, a controller, or any combination of general-purpose computing devices, reduced instruction set computing (RISC) devices, application-specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other related logic devices, including mechanical and quantum computers. The processor 1460 may also compriseanother hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 1460 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0107] The memory 1464 may include a cache memory (e.g., a cache memory of the processor 1460), random access memory (RAM), magnetoresistive RAM (MRAM), readonly memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In an aspect, the memory 1464 includes a non-transitory computer-readable medium. The memory 1464 may store instructions 1466. The instructions 1466 may include instructions that, when executed by the processor 1460, cause the processor 1460 to perform the operations described herein. Instructions 1466 may also be referred to as code. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

[0108] The communication module 1468 can include any electronic circuitry and / or logic circuitry to facilitate direct or indirect communication of data between the processor circuit 1450, and other processors or devices. In that regard, the communication module 1468 can be an input / output (VO) device. In some instances, the communication module 1468 facilitates direct or indirect communication between various elements of the processor circuit 1450 and / or the system 200 or 1000. The communication module 1468 may communicate within the processor circuit 1450 through numerous methods or protocols. Serial communication protocols may include but are not limited to United States Serial Protocol Interface (US SPI), Inter-Integrated Circuit (I2C), Recommended Standard 232 (RS-232), RS- 485, Controller Area Network (CAN), Ethernet, Aeronautical Radio, Incorporated 429 (ARINC 429), MODBUS, Military Standard 1553 (MIL-STD-1553), or any other suitable method or protocol. Parallel protocols include but are not limited to Industry Standard Architecture (ISA), Advanced Technology Attachment (ATA), Small Computer System Interface (SCSI), Peripheral Component Interconnect (PCI), Institute of Electrical and Electronics Engineers 488 (IEEE-488), IEEE-1284, and other suitable protocols. Whereappropriate, serial and parallel communications may be bridged by a Universal Asynchronous Receiver Transmitter (UART), Universal Synchronous Receiver Transmitter (US ART), or other appropriate subsystem.

[0109] External communication (including but not limited to software updates, firmware updates, preset sharing between the processor and central server, or readings from associated devices) may be accomplished using any suitable wireless or wired communication technology, such as a cable interface such as a universal serial bus (USB), micro USB, Lightning, or FireWire interface, Bluetooth, Wi-Fi, ZigBee, Li-Fi, or cellular data connections such as 2G / GSM (global system for mobiles) , 3G / UMTS (universal mobile telecommunications system), 4G, long term evolution (LTE), WiMax, or 5G. For example, a Bluetooth Low Energy (BLE) radio can be used to establish connectivity with a cloud service, for transmission of data, and for receipt of software patches. The controller may be configured to communicate with a remote server, or a local device such as a laptop, tablet, or handheld device, or may include a display capable of showing status variables and other information. Information may also be transferred on physical media such as a USB flash drive or memory stick.

[0110] Figure 15 is an enlarged view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 7, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, electrodes 254, non-compliant balloon 256, and compliant balloon 258. Also visible is a flexible or compliant substrate 410 which supports the electrodes 254. The electrodes 254 may for example be coated, printed, or attached to the substrate 410.

[0111] The structure shown in Fig. 15 is similar to the structure shown in Fig. 4A. However, depending on the implementation, the non-compliant balloon 256, compliant balloon 258, and the electrodes 254 can have equal or non-equal lengths. In the aspects illustrated in Fig. 7 and Fig. 15, the compliant balloon 258 and the electrode assembly 1510 have approximately equal lengths LE (e.g., equal to within ± 1%, ± 5%, etc.), but that length LE is only approximately half of the length LB of the non-compliant balloon 256. In contrast, in Fig. 4A, the non-compliant balloon 256, the compliant balloon 258, and the electrode assembly 1510 (comprising the substrate 410 and electrodes 254) are all closer to being equal lengths (though they may not be of exactly equal lengths).

[0112] Additionally, as shown in Fig. 15, the non-compliant balloon 256 can include a proximal portion 1520 and a distal portion 1530. The compliant balloon 258 and the electrode assembly 1510 can be provided only at the distal portion 1530 (and not theproximal portion 1520) of the compliant balloon 258. In contrast, in Fig. 4A, the compliant balloon 258 and the electrode assembly are centered relative to the non-compliant balloon 256, rather than being biased towards the distal portion 1530 as in Fig. 15.

[0113] As shown in Figure 7, during use, the proximal portion 1520 of the non-compliant balloon 256 can be positioned within the aortic valve (e.g., adjacent to, in contact with, and / or proximate to the valve annulus and / or valve leaflets) and the distal portion 1530 of the non- compliant balloon 256 can be positioned within the LVOT (e.g., adjacent to, in contact with, and / or proximate to interventricular septum) provide ablation to the interventricular septum.

[0114] In other aspects, the compliant balloon 258 and electrode assembly 1510 can be positioned at the proximal portion 1520 of the non-compliant balloon 256.

[0115] In some aspects, the PFA catheter 250 (e.g., the non-compliant balloon 256) can include temporary valve 1610, as described with respect to, e.g., Figs. 16, 17, 18A, and 18B. The PFA catheter 250 (e.g., the non-compliant balloon 256) can also include a valve lumen 1540, to allow blood flow 2410 longitudinally through the non-compliant balloon 256 without affecting the inflation state of the non-compliant balloon. The non-compliant balloon 256 in this example can have a toroid or toroid-like cross-sectional shape (as shown in Figs. 17, 18 A, and 18B). The valve lumen 1540 can be open space that is defined by surface(s) of the non-compliant balloon 256. These surface(s) can be outer surfaces of the non-compliant balloon 256 in that they are an outer extent of the balloon, but the toroid or toroid-like cross- sectional shape of the balloon is such that these outer surfaces are located towards an interior of the balloon. The temporary valve 610 can be positioned along the length of the non- compliant balloon 256, within the valve lumen 1540. The valve lumen can be laterally offset from the central longitudinal axis of the non-compliant balloon 256 (as shown in Figs. 15, 17A, 18 A, and 18B) or laterally centered. The configuration of the PFA catheter 250 with the temporary valve 1610 and the valve lumen 1540 can be used when no rapid pacing is performed during ablation of the interventricular septum.

[0116] The temporary valve 1610 can be used in the lumen 1540 along the longitudinal axis of the non-compliant balloon 256, in order to allow for proper control of blood flow in the event that rapid pacing of the heart is not used during the ablation. If rapid pacing is employed, then there would not be any need to allow for blood to flow through or around the non-compliant balloon 256 used to position the electrodes of the PFA device with respect to the aortic valve. If rapid pacing were not utilized, the pressure of the blood trying to exit the left ventricle would push the PFA device out of position with each cardiac cycle. Adding only the lumen 1540 to allow for blood to flow through or around the device partially addressesthe issue. Because the natural aortic valve is being held open by the non-compliant ballon 256 in the expanded configuration, the temporary valve 1610 is also provided to stop blood from flowing back through the native aortic valve and / or the lumen 1540 during portions of the cardiac cycle.

[0117] In other aspects, the PFA catheter 250 (e.g., the non-compliant balloon 256) does not have the valve lumen 1540 and / or temporary valve 1610, such as when rapid pacing is performed during ablation of the interventricular septum.

[0118] Figure 16 is a schematic, diagrammatic view, in block diagram form, of a system 1600 according to aspects of the present disclosure. Visible are the console 202, processor 210, display 220, pulsed field generator 240, memory 205, input device 230, pulsed field ablation catheter 250, flexible elongate member 252, electrodes 254, non-compliant balloon 256, inflation fluid source 270, compliant balloon 250, inflation fluid source 280, and guidewire 260. Components of the system in Fig. 16 are similar to those shown in Fig. 2. However, the pulsed field ablation catheter 250 in Figure 16 additionally includes a temporary valve 1610. Aspects of the temporary valve 1610 are illustrated in Figures 17, 18 A, and 18B.

[0119] This configuration of the PFA catheter 250 can be used when no rapid pacing of the heart is performed. In that regard, the temporary valve 1610 opens to allows blood flow from the left ventricle into to the aorta (during systole) and closes to prevent backwards blood flow from the aorta into the left ventricle (during diastole). The PFA catheter 250 with temporary valve 1610 can be used during the intracardiac procedure in which the electrodes provide ablation to the interventricular septum.

[0120] In some aspects, the procedure to provide ablation is performed on the patient on a different (earlier) day than the procedure to actually implant the replacement valve (e.g., replacement aortic valve or replacement mitral valve). For example, the ablation procedure can be performed one week earlier than the replacement valve implantation procedure. As described herein, the ablation procedure treats hypertrophic cardiomyopathy (e.g., thickening of the heart muscle or myocardium, such as the interventricular septum) and / or left ventricular outflow tract occlusions (LVOTO). During the implantation procedure, whether or not rapid pacing of the heart is performed can depend on whether the replacement valve is balloon-expanded or self-expanding (not balloon-expanded). When the replacement valve is balloon expanded, rapid pacing is used to minimize the amount of blood flow that can push the replacement valve and / or its associated delivery catheter out of position (e.g., the valve annular). When the replacement valve is self expanding, rapid pacing need not be used. Forexample, because there is no balloon to expand the replacement valve, there is less surface area for the blood flow to push against (to push the replacement valve and / or its associated delivery catheter out of position).

[0121] When the ablation procedure is performed on a different day than implantation procedure, rapid pacing or no rapid pacing can be used for the ablation procedure. No rapid pacing could be performed when the artificial valve (to be implanted later) is known to be self-expanding. In that situation, the physician may not want to use rapid pacing during the ablation procedure when the physician does not plan to use rapid pacing during the implantation procedure either. In some situations, no rapid pacing may be used because the patient may not tolerate the rapid pacing well because of the patient’s physiological condition.

[0122] In contrast, when rapid pacing is used, either the PFA catheter without temporary valve or the PFA catheter with temporary valve can be used. Use of PFA catheter with temporary valve with rapid pacing is not an issue, through the temporary valve does not function much (because not much blood flow is present to open / close the temporary valve).

[0123] The valve 1610 is called temporary because it is taking the place of the patient’s natural valve during the intracardiac PFA procedure, to allow for aortic valve function during the ablation, assuming rapid pacing of the heart is not employed.

[0124] Figure 17 is an enlarged view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 15, according to aspects of the present disclosure. Visible are the guidewire 260, flexible elongate member 252, electrodes 254, non-compliant balloon 256, and compliant balloon 258. Also visible is a flexible or compliant substrate 410 which supports the electrodes 254. The electrodes may for example be coated, printed, or attached to the substrate 410.

[0125] The example of Figure 17 shows the unexpanded configuration of the PFA catheter 250 along section line 17-17 of Fig. 15. The structure shown in Figure 17 is similar to the structure shown Fig. 4B, except that the PFA catheter 250 additionally includes the temporary valve 1610. Depending on the implementation, the non-compliant balloon 256 can include one or multiple temporary valves 1610. In Figure 17, one temporary valve 1610 is shown. The temporary valve 1610 can be coupled to the non-compliant balloon 256 via a valve lumen that allows blood to flow through the non-compliant balloon 256 (e.g., in a desired direction only), without affecting the inflation state of the non-compliant balloon 256. The temporary valve 1610 may be bonded to outer surface(s) of the non-compliant balloon(which define the valve lumen 1540 in Fig. 15) via thermal bonding, laser bonding, adhesives, other methods, and / or combinations thereof.

[0126] Coupling between the temporary valve 1610 and the non-compliant balloon 256 can allow for expansion of the non-compliant balloon 256 without adversely impacting how the temporary valve 1610 and the non-compliant balloon 256 are coupled. The temporary valve 1610 can be made of flexible materials, such as a polymer or natural tissue (e.g., porcine tissue or bovine tissue). The temporary valve can include any suitable number of prosthetic valve leaflets 1710 (e.g., three leaflets 1710, as shown, two leaflets 1710 for a duckbill configuration), etc.)

[0127] Figure 18A is a lateral cross-sectional view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 15 along cross-section line 17-17, in the expanded or inflated state, according to aspects of the present disclosure. Visible are the flexible elongate member 252, guidewire 260, guidewire lumen 420, non-compliant balloon 256, inflation fluid 510, compliant balloon 258, inflation fluid 520, flexible substrate 410, and electrode 254. Figure 18A shows the leaflets 1710 of the temporary valve 1610 in a closed configuration. In an example when positioned within the aortic valve, during diastole, the temporary valve 1710 closes to prevent backwards blood flow from the aorta into the left ventricle.

[0128] Figure 18B is a lateral cross-sectional view of the distal portion 370 of the pulsed field ablation catheter 250 of Figure 15 along cross-section line 17-17, in the expanded or inflated state, according to aspects of the present disclosure. Visible are the flexible elongate member 252, guidewire 260, guidewire lumen 420, non-compliant balloon 256, inflation fluid 510, compliant balloon 258, inflation fluid 520, flexible substrate 410, and electrode 254. Figure 18B shows the leaflets 1710 of the temporary valve 1610 in an open configuration. In an example when positioned within the aortic valve, during systole, the valve 1610 opens to allows blood flow from the left ventricle into to the aorta. That is, the blood is able to flow from the left ventricle, longitudinally through the valve lumen 1540 (Fig. 15) of the non-compliant balloon 256 (via the temporary valve 1610), and into the aorta. When the non-compliant balloon 256 is in the unexpanded state, the temporary valve 1610 is compacted / compressed (a smaller size); when the non-compliant balloon 256 is inflated, the valve 1610 is uncompressed / expanded (a bigger size).

[0129] Figure 19 is a schematic, diagrammatic view, in block diagram form, of a system 1900 according to aspects of the present disclosure. Similar to the other systems described herein (e.g., system 200 in Fig. 2, system 1000 in Fig. 10, system 1600 in Fig. 16), the system1900 provides a pulsed field ablation device to treat hypertrophic cardiomyopathy, as well as left ventricular outflow tract occlusions (LVOTO) caused by implantation of a valve implant (e.g., replacement mitral valve, replacement aortic valve). Visible are the console 202, processor 210, display 220, pulsed field generator 240, memory 205, input device 230, compliant balloon 250, and inflation fluid source 280, and guidewire 260. Components of the system in Fig. 19 are similar to those shown in Fig. 2. However, the pulsed field ablation catheter 250 has been replaced with an intracardiac pulsed field ablation device 1950, which includes a retrievable stent 1910. The retrievable stent 1910 includes a stent 1920 that is operated by, and coupled to the distal end of, a push wire or push rod 1930 (which may be considered a flexible elongate member). The push wire or push rod 1930 may for example be made of metal, metal alloy, polymer, and / or combinations thereof, and can have any suitable cross-sectional shape (e.g., circular, square, etc.). The push wire or push rod 1930 can have a solid cross-section as shown for example in Figures 25 and 26.

[0130] The intracardiac PF A device 1950 is introduced into the heart of the patient via a sheath 1940. The intracardiac PFA device 1950 utilizes a stent-like design in place of the non-compliant balloon.

[0131] An example of forming the stent 1920 can include a nitinol tube being laser cut with a cell pattern, expanded, heat set, and attached to a pull wire so that once deployed, it can be retrieved back into the delivery sheath 1940. The stent 1920 may or may not include a temporary valve 1610 that takes the place of the aortic valve, which is held open by the stent 1920 during the ablation procedure and rapid pacing of the heart is not utilized during the treatment.

[0132] The non-compliant balloon 256 and compliant balloon 258 are examples of expandable members (e.g., members with an expanded configuration and an unexpanded / constrained configuration). The stent 1920 is another example of an expandable member (with, e.g., an expanded configuration and an unexpanded / constrained configuration). In Fig. 19, the stent takes place of the non-compliant balloon 256 in Fig. 2. The compliant balloon 258 and the electrode assembly (including the electrodes 254) are coupled to the stent 1920, rather than being coupled to the non-compliant balloon.

[0133] The push wire 1930 can be translated distally (in a longitudinal direction) with the stent 1920 attached, such that the stent 1920 is positioned within the aortic valve (e.g., adjacent to, in contact with, and / or proximate to the valve annulus and / or valve leaflets).The push wire 1930 can be translated proximally (e.g., in the proximal direction) to remove the stent 1920 from the aortic valve. The word “retrievable” is used to refer to the fact thatthe stent remains attached to the push wire 1930 such that the stent 1920 can be selectively translated (e.g. advanced, retrieved) and / or rotated by the physician.

[0134] A sheath 1940 (also known as an introducer sheath, delivery sheath, etc.) can be used to position the intracardiac PFA device 1950 at the desired location (e.g., within the aortic valve). The sheath 1940 includes a lumen that receives the retrievable stent 1910. The sheath wall (which defines the lumen) maintains the stent 1920 in its constrained configuration while the stent 1920 remains within the sheath. The intracardiac PFA device 1950 and the retrievable stent 1910 can have movement (e.g., translation, rotation) relative to one another. The guidewire 260 can be used to position the sheath 1940 at the desired location (e.g., within the aortic valve). After the sheath 1940 is positioned, then the guidewire 260 can be removed from the sheath lumen, and the intracardiac PFA device 1950 can be introduced into the sheath lumen to be positioned at the desired location.

[0135] In other aspects, the guidewire 260 can be used to position the intracardiac PFA device 1950. For example, the guidewire 260 can extend longitudinally through the stent 1920 and / or alongside the push wire 1930. The intracardiac pulsed field ablation device 1950, together with the delivery sheath 1940, may be considered an intracardiac pulsed field ablation catheter.

[0136] Figure 20 is a schematic, diagrammatic longitudinal cross-sectional side view of an example intracardiac pulsed field ablation device 1950, according to aspects of the present disclosure. Visible are the electrodes 254, compliant balloon 258, connector 310, compliant balloon fill port 330 to which the compliant balloon inflation fluid source can be attached (see Figure 2). The connector 310 also includes an electrical connector 340 to which a cable 350 attaches, to provide electrical energy to the electrodes 254. The cable 350 also attaches to a console connector 360 that connects to the console 202 and / or to the pulsed field generator 240 (see Figure 2).

[0137] Also visible are the delivery sheath 1940, push wire 1930, and stent 1920, along with a compliant balloon inflation lumen 2010, electrical signal lines 2020, and a rapid exchange (RX) port or retention tube 2030 through which the balloon inflation lumen 2010 and electrical signal lines 2020 pass. In an example, the RX port or retention tube 2030 is fixedly / tightly attached to the push wire 1930, while the balloon inflation lumen 2010 and electrical signal lines 2020 are free to translate proximally and distally through the rapid exchange port 2030, but are constrained from separating radially from the push wire 1930.

[0138] The intracardiac PFA device 1950 (including push wire 1930 and stent 1920) includes a distal portion 370 terminating at distal end, and a proximal portion 2040terminating at proximal end. Similarly, the sheath 1940 includes a distal portion 2070 terminating at a distal end, a proximal portion 2050 terminating at a proximal end, and a sheath wall 2060 defining a sheath lumen 2080. A user can grip and move (translate / rotate) proximal portion 2040 of the push wire 1930, to cause corresponding movement of the distal portion 370 of the intracardiac PFA device 1950.

[0139] Figures 20-22 show that the flexible substrate 410 (part of the electrode assembly 1510 of Figure 15) and the inflation lumen 2010 for the compliant balloon 258 extends between proximal and distal portions of the intracardiac PFA device 1950.

[0140] Figure 21 is an enlarged view of the distal portion 370 of the intracardiac PFA device 1950 of Figure 20 in its constrained or unexpanded state, according to aspects of the present disclosure. Visible are the sheath 1940, sheath wall 2060, sheath lumen 2080, electrical wire 2020, compliant balloon 258, inflation lumen 2010, electrode substrate 410, electrodes 254, stent 1920, and push wire 1930. Also visible are attachment points or couplings 2110 that attach the compliant balloon 258 to the substrate 410 and to the stent 1920. These may be thermal bonds, laser bonds, adhesive bonds, mechanical attachments, or otherwise. For example, the balloon 258 may be attached mechanically to the stent, with a loop that would go around a stent strut and the shaft 2010 of the balloon that is used to inflate the balloon. In some aspects, a short section of the shaft 2010 can extend distally from the balloon, such as how an angioplasty balloon would be constructed. The couplings 2110 are provided only at the distal portion of the stent 1920 (and not at the proximal portion of the stent 1920). Thus, the proximal portions of the stent 1920, the compliant balloon 258, and the substrate 410 can have movement relative to one another (which would occur, e.g., when the stent 1920 transitions between un expanded and expanded configurations, as described below). In the example shown in Figure 21, the rapid exchange port or retention tube 2030, attached to the push wire is in Position A, such that the stent 1920 is in its constrained or unexpanded state, because it is compressed by the sheath wall 2060 and thus prevented from expanding. Thus, the stent 1920 has a length of LCOntstrained and a diameter of DCOnstrained, which are determined at least in part by the geometry of the sheath lumen 2080.

[0141] Figures 20-22 show that the flexible substrate 410 (part of the electrode assembly 1510 of Figure 15) and the inflation lumen 2010 for the compliant balloon 258 extends between proximal and distal portions of the intracardiac PFA device 1950.

[0142] Figure 22 is an enlarged view of the distal portion 370 of the intracardiac PFA device 1950 of Figure 20 in its expanded state, according to aspects of the present disclosure. Visible are the sheath 1940, sheath wall 2060, sheath lumen 2080, electrical wire 2020,compliant balloon 258, inflation lumen 2010, electrode substrate 410, electrodes 254, stent 1920, push wire 1930, and attachment points or couplings 2110.

[0143] In the example shown in Figure 22, the stent 1920 is a self-expanding stent, e.g., the stent structure is biased to expand when it is not constrained by the sheath 1940. Thus, in the constrained / unexpanded configuration shown in Figure 21, when inside of the sheath 1940, the stent is pressing against the sheath wall 2060, and the sheath wall 2060 is preventing expansion. Conversely, in Figure 22, the sheath wall 2060 does not constrain the stent 1920, so the stent 1920 is free to expand. To transition into the expanded configuration, there may be relative movement between the sheath 1940 and the intracardiac PFA device 1950. For example, either the sheath 1940 is moved in a proximal direction, while the intracardiac PFA device 1950 is stationary, or the intracardiac PFA device 1950 is moved distally while the sheath 1940 is stationary, or both the sheath 1940 is moved proximally and thee intracardiac PFA device 1950 is moved distally. In any of these cases, the net result is that the stent is moved outside of the sheath lumen 2080 such that sheath wall 2060 no longer prevents expansion of the stent 1920 (e.g., because there is no contact between stent and sheath wall).

[0144] In the example shown in Figure 22, the rapid exchange port or retention tube 2030 (anchored to the push wire 1930) has been pushed in a distal direction to position B relative to the compliant balloon 258 and electrodes 254, to enable expansion of the stent 1920. The intracardiac PFA device 1950 as a whole has also been pushed in a distal direction such that the stent 1920 is now entirely outside of the sheath 1940. Since the sheath wall 2060 no longer constrains the size and shape of the stent 1920, the stent 1920 has expanded into its expanded state, with a length Lexpanded that is shorter than LCOnstrained, and a diameter Dexpanded that is larger than Dconstrained. Similarly, when pulled back into the sheath lumen 2080, the stent 1920 will once again compress so that its length is LCOnstrained and its diameter is Dconstrained-

[0145] When the stent 1920 transitions between unexpanded and expanded configurations, as described below, the proximal portions of the stent 1920, the compliant balloon 258, and the substrate 410 have movement relative to one another. The proximal portions of the stent 1920, the compliant balloon 258, and the substrate 410 are more aligned in Fig. 21 (with the stent in the expanded configuration), whereas the proximal portion of the stent 1920 is more spaced from the proximal portions of the compliant balloon 258 and the substrate 410 in Fig. 20 (with the stent in the unexpanded / constrained configuration).

[0146] The intracardiac PF A device 1950 includes the rapid exchange port or retention tube 2030 (e.g., with a retention wall defining a retention lumen). The rapid exchange port or retention tube is coupled to the distal portion of the push wire 1930 (e.g., at the distal end of the push wire 1920 or spaced proximally from the distal end of the push wire 1930). The rapid exchange port receives and loosely couples the compliant balloon inflation lumen 2010, the flexible substrate 410 of the electrode assembly, and the electrical signal lines 2020 to the push wire 1930. The rapid exchange port or retention tube 2030 prevents the prevents radial separation of the electrical signal lines 2020 (e.g., in the flexible substrate 410) and the inflation lumen 2010 from push wire 1930, but allows relative translation between the push wire on the one hand, and the inflation lumen and the electrical signal lines 2020 within the flexible substrate 410.

[0147] Figures 20-22 show that the flexible substrate 410 (part of the electrode assembly 1510 of Figure 15) and the inflation lumen 2010 for the compliant balloon 258 extends between proximal and distal portions of the intracardiac PF A device 1950.

[0148] Figure 23 is an enlarged view of the distal portion 370 of the intracardiac PFA device 1950 in its expanded state, according to aspects of the present disclosure. Visible are the sheath 1940, sheath wall 2060, sheath lumen 2080, compliant balloon 258, inflation lumen 2010, electrode substrate 410, electrodes 254, stent 1920, push wire 1930, and attachment points or couplings 2110. The structures shown in Figure 23 are similar to those shown in Figure 22, except that the substrate 410 does not extend back to the proximal portion of the intracardiac PFA device 1950. Rather, the substrate 410 is only at the distal portion 370 of the intracardiac PFA device 1950, and the electrical traces or electrical lines 2020 are instead carried by a cable 2320.

[0149] Figure 24 is an enlarged view of the distal portion 370 of the intracardiac PFA device 1950 in its expanded state, according to aspects of the present disclosure. Visible are the sheath 1940, sheath wall 2060, sheath lumen 2080, compliant balloon 258, inflation lumen 2010, electrode substrate 410, electrodes 254, stent 1920, push wire 1930, attachment points or couplings 2110, and electrical traces or electrical lines 2020 within the electrical cable 2320. The structures shown in Figure 24 are similar to those shown in Figure 23, except that the stent 1920 includes a temporary valve 1610, as described above in Figures 17- 18B. The temporary valve 1610 may for example be stitched / sewn to the stent 1920, to allow for expansion and contraction of the stent 1920 and valve 1610 together, without overconstraining the bonding of the valve 1610 to the stent 1920.

[0150] The temporary valve 1610 allows blood flow 2410 in a desired direction (e.g., out of the left ventricle and into the aorta) while preventing blood flow in the opposite direction (e.g., out of the aorta and into the left ventricle). This may for example allow the intracardiac PFA device 1950 to be used for septum ablation procedures without rapid pacing of the heart. When rapid pacing is not utilized, the temporary valve 1610 prevents unwanted flow of blood back into the heart from the aorta. Unlike the non-compliant ballon 256 in Fig. 15, which has a dedicated lumen 1540 for the blood flow 2410, the stent 1920 need not have a dedicated lumen because the interior of the stent is open. That is, the interior of the stent 1920 is already a lumen to allow blood flow 2410.

[0151] As similarly described with respect to Fig. 15, the stent 1920, compliant balloon 258, and the electrodes 254 can have equal or non-equal lengths, and / or the compliant balloon 258 and / or the electrodes 254 can be longitudinally centered relative to the stent 1920, and / or positioned in only a distal portion or only a proximal portion of the stent 1920.

[0152] Figs. 20-24 can be partial longitudinal cross-sectional views, in that the RX portion or retention tube 2030 is not shown in cross-section. The lateral cross-sectional view of the RX port or retention tube 2030 is shown in Figs. 25 and 26.

[0153] Figure 25 is a cross-sectional view of at least a portion of the intracardiac PFA device 1950, taken along cut line 25-25 of Figure 22, according to aspects of the present disclosure. Visible are the push wire or push rod 1930 and the rapid exchange port or retention tube 2030, which are fixedly / tightly coupled by a bond 2530 such as a weld, solder joint, or adhesive, such that there is no relative movement between the push wire 1930 and the RX port or retention tube 2030. The push wire 1930 has a solid cross-section, whereas the rapid exchange port or retention tube 2030 is hollow, with a retention wall 2510 defining a retention lumen 2520. Passing through the retention lumen 2520 are the compliant balloon inflation lumen and the electrode substrate 410, which carries electrical traces or electrical lines 2020 to energize the electrodes.

[0154] The retention lumen 2520 loosely couples the compliant balloon inflation lumen 2010 and the electrical signal lines 2020 for the electrodes, preventing them from radially separating from the push wire 1930, but allows relative translation between the push wire 1930 on the one hand, and the inflation lumen 2010 and the electrical signal lines 2020 (e.g., the flexible substrate 410) on the other.

[0155] Figure 26 is a cross-sectional view of at least a portion of the intracardiac PFA device 1950, taken along cut line 26-26 of Figure 23, according to aspects of the present disclosure. Visible are the push wire 1930 and the rapid exchange port or retention tube2030, which are fixedly / tightly coupled by a bond 2530 such as a weld, solder joint, or adhesive such that there is no relative movement between the push wire 1930 and the RX port or retention tube 2030. The push wire 1930 has a solid cross-section, whereas the rapid exchange port or retention tube 2030 is hollow, with a retention wall 2510 defining a retention lumen 2520. Passing through the retention lumen 2520 are the compliant balloon inflation lumen and the electrical cable 2320, which carries electrical traces or electrical lines 2020 to energize the electrodes. Each of the electrical wires or traces 2020 may have its own insulation layer, and all of the wires or traces 2020 may be surrounded by an outer insulator that forms them into the cable 2320.

[0156] In the examples shown in Figs. 20-26, the outer surface of the retention wall 2510 of the RX port or retention tube 2030 is coupled to the push wire 1930. In other examples, the outer surface of the retention wall 2510 (defining the retention lumen 2520) is coupled to the push wire 1930. In this configuration, the push wire 1930 would be located inside the retention lumen 2520, in addition to the inflation lumen 2010 and the electrical signal lines 2020. However, unlike the inflation lumen 2010 and the electrical signal lines 2020, which are loosely coupled (relative movement possible), the push wire 1930 is fixedly / tightly coupled to the RX port or retention tube 2030 (no relative movement possible).

[0157] Figure 27 is an enlarged view of the distal portion 370 of the intracardiac pulsed field ablation catheter 1950 of Figure 23, wherein both the stent 1920 and the compliant balloon 258 are in the inflated or expanded state, according to aspects of the present disclosure. Visible are the push wire 1930, inflation lumen 2010, electrical cable 2320, flexible substrate 410, electrodes 254, stent 1920, and compliant balloon 258. In the example shown in Figure 27, the stent 1920 is in its expanded state, and the compliant balloon 258 is filled with an inflation fluid 520 and is thus also in an expanded state.

[0158] Also visible is heart tissue, including the interventricular septum 130 and the LVOT wall 530 (which is part of the annulus of the aortic valve 124 - see Figure IB). In practice, the pulsed field ablation device 1950 is maneuvered into the LVOT, and the stent 1920 is expanded in order to maintain the positioning of the PFA catheter 250 within the aortic valve 124, which also props open the aortic valve 124 (see Figures IB and 7). Depending on the implementation, the heart may be rapid-cycled during this process to reduce the pressure gradient across the aortic valve, so that it doesn’t push the stent out of place during the heart cycle, or allow the backflow of blood into the heart. Next, the PFA device 1950 is rotated until the electrodes 254 are aligned with the interventricular septum 130, and the compliant balloon 258 is inflated with the inflation fluid 520, such that theflexible substrate 410 and the electrodes 254 are pressed against, and comply with the contours of, the septum 130. Next, the electrodes are activated in pulses as described above (e.g., for a period of between 1 second and 5 seconds), such that the pulsed electric field delivers electrical energy to the septum 130 that causes electroporation of cells of the septum 130 that are within a threshold distance of the electrodes (e.g., a given field strength). This electroporation in turn triggers the start of apoptosis or programmed cell death for at least some of the affected cells. This apoptosis (which may take up to 24 hours to complete) has the effect of thinning the interventricular septum and thus widening the left ventricular outflow tract.

[0159] In some aspects, the stent 1920, compliant balloon 258, and flexible substrate 410 may form a presser mechanism that is configured to press the electrodes against the tissue to be ablated. Other types of presser mechanisms are contemplated. Because the stent 1920 may not conform to the contours of tissue against which it is pressed, a gap 540 may exist between the stent 1920 and the tissue 530.

[0160] Because the stent 1920 does not include a temporary valve, the device shown in Figure 27 may be used in conjunction with rapid pacing of the heart.

[0161] Figure 28 is an enlarged view of the distal portion 370 of the intracardiac pulsed field ablation catheter 1950 of Figure 24, wherein both the stent 1920 and the compliant balloon 258 are in the inflated or expanded state, according to aspects of the present disclosure. Visible are the push wire 1930, inflation lumen 2010, electrical cable 2320, flexible substrate 410, electrodes 254, stent 1920, compliant balloon 258, septum 130, LVOT wall 530, and gap 540. The structure shown in Figure 24 may be similar to that shown in Figure 23, except that the stent 1920 includes a temporary valve 1610, which allows blood flow 2410 in a desired direction (e.g., out of the left ventricle and into the aorta) and not in the opposite direction (e.g., from the aorta and back into the left ventricle of the heart). Thus, the device shown in Figure 28 may be suitable for use without rapid pacing of the heart.

[0162] Figure 29 is a lateral cross-sectional view of the PF A device 1950 of Figure 27, in the expanded configuration, taken along cut line 29-29, according to aspects of the present disclosure. Visible are the expanded state stent 1920, the compliant balloon 258, the inflation fluid 520, the flexible substrate 410, and the electrodes 254. Because of the lack of a temporary valve, the device shown in Figure 29 may be suitable for use with rapid pacing of the heart.

[0163] Figure 30 is a lateral cross-sectional view of the PF A device 1950 of Figure 28, in the expanded configuration, taken along cut line 30-30, according to aspects of the presentdisclosure. Visible are the expanded state stent 1920, the compliant balloon 258, the inflation fluid 520, the flexible substrate 410, and the electrodes 254. In the example shown in Figure 30, the stent 1920 includes a temporary valve 1610. As described above in Figure 28, the temporary valve 1610 may allow the device 1950 to be used without rapid pacing of the heart. When the device 1950 is positioned within the aortic valve, the leaflets 1710 of the temporary valve 1610 can for example be open during diastole (to allow blood flow out of the left ventricle and into the aorta) and closed during systole (to prevent blood flow from the aorta back into the left ventricle, as similarly described with respect to Figs. 18A and 18B. Stitching 3010 can be used to couple the temporary valve 1610 to the stent 1920. For example, the stitching 3010 can attach the outer edges of the leaflets 1710 to the stent 1920. The stitching 3010 can be considered a loose coupling in that it keeps the temporary valve 1610 and the stent 1920 together (preventing the temporary valve 1610 and the stent 1920 from separating), while still allowing the stent 1920 to transition between the unexpanded and expanded configurations without any damage to temporary valve 1610. When the stent 1920 is in the unexpanded state, the temporary valve 1610 is compacted / compressed (a smaller size); when the stent 1920 is inflated, the valve 1610 is uncompressed / expanded (a bigger size)

[0164] Accordingly, it can be seen that the interventricular septum ablation system advantageously provides an increase to the volume and / or area (e.g., surface area, cross- sectional area) of the left ventricular outflow channel, and thus improves blood flow, without cutting tissue, without triggering inflammation or edema, and without the need to perform an open-heart procedure.

[0165] A number of variations are possible on the examples and aspects described above. For example, some aspects include a compliant balloon with electrodes formed on its outer surface, obviating the need for a non-compliant balloon and flexible substrate. .

[0166] The interventricular septum ablation system is intended to treat left ventricular outflow tract obstruction (LVOTO), hypertrophic cardiomyopathy, and / or other applications where a reduction in tissue volume is desired. For example, triggering apoptosis of the osteocytes could in calcified myocardial or vascular tissue may be a desirable way to treat calcific disease. This may require higher voltages than those required to trigger apoptosis in myocardium cells (e.g., up to 1500 V / cm). In some aspects, the system can also be used for in-stent restenosis (ISR) treatment, which can use a field of up to 1750 Volts / cm at a frequency of up to 1 kHz. More generally, the technology described herein may be applied tothe interventricular septum, interatrial septum, vascular tissue, tissue of the heart, and / or other tissue inside the patient body.

[0167] Accordingly, the logical operations making up the aspects of the technology described herein are referred to variously as operations, steps, objects, elements, components, or modules. Furthermore, it should be understood that these may occur or be performed or arranged in any order, unless explicitly claimed otherwise or a specific order is inherently necessitated by the claim language.

[0168] All directional references e.g., upper, lower, inner, outer, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, proximal, and distal are only used for identification purposes to aid the reader’s understanding of the claimed subject matter, and do not create limitations, particularly as to the position, orientation, or use of the interventricular septum ablation system. Connection references, e.g., attached, coupled, connected, joined, or “in communication with” are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other. The term “or” shall be interpreted to mean “and / or” rather than “exclusive or.” The word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. Unless otherwise noted in the claims, stated values shall be interpreted as illustrative only and shall not be taken to be limiting.

[0169] The above specification, examples and data provide a complete description of the structure and use of exemplary aspects of the interventricular septum ablation system as defined in the claims. Although various aspects of the claimed subject matter have been described above with a certain degree of particularity, or with reference to one or more individual aspects, those skilled in the art could make numerous alterations to the disclosed aspects without departing from the spirit or scope of the claimed subject matter.

[0170] Still other aspects are contemplated. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative only of particular aspects and not limiting. Changes in detail or structure may be made without departing from the basic elements of the subject matter as defined in the following claims.

Claims

CLAIMSWhat is claimed is:

1. An apparatus, comprising: a flexible elongate member configured to be advanced through a blood vessel and positioned inside of a heart of a patient; at least one expandable member coupled to a distal portion of the flexible elongate member; and a plurality of electrodes coupled to the at least one expandable member, wherein, when the at least one expandable member comprises an expanded configuration, the at least one expandable member is configured to bring the plurality of electrodes into contact with an interventricular septum of the heart, wherein, when the plurality of electrodes is in contact with the interventricular septum, the plurality of electrodes is configured to deliver electrical energy to the interventricular septum to reduce a volume of the interventricular septum.

2. The apparatus of claim 1, wherein the flexible elongate member comprises a catheter, wherein the at least one expandable member comprises at least one balloon.

3. The apparatus of claim 2, further comprising one or more inflation fluid sources configured to inflate the at least one balloon.

4. The apparatus of claim 3, wherein the one or more inflation fluid sources comprises a syringe or an endoflator.

5. The apparatus of claim 2, wherein the at least one balloon comprises at least one of a non-compliant balloon or a compliant balloon.

6. The apparatus of claim 2, wherein the at least one balloon comprises a non-compliant balloon and a compliant balloon, and wherein the plurality of electrodes is coupled to the compliant balloon.

7. The apparatus of claim 6, wherein the apparatus comprises a flexible substrate coupled to the compliant balloon and the plurality of electrodes.

8. The apparatus of claim 6, wherein, when the non-compliant balloon comprises the expanded configuration, the non-compliant balloon is configured to contact tissue of the heart such that the flexible elongate member is stationary relative to the heart, and wherein, when the compliant balloon comprises the expanded configuration, the compliant balloon is configured to cause the plurality of electrodes to conform to a shape of the interventricular septum.

9. The apparatus of claim 6, wherein the non-compliant balloon is centered relative to the flexible elongate member, and wherein the compliant balloon is laterally offset relative to the flexible elongate member.

10. The apparatus of claim 1, wherein the electrical energy delivered by the plurality of electrodes comprises pulsed field ablation.

11. The apparatus of claim 1, wherein the flexible elongate member comprises a push wire, and wherein the at least one expandable member comprises a retrievable stent coupled to a distal portion of the push wire.

12. The apparatus of claim 11, wherein the at least one expandable member comprises a compliant balloon coupled to the retrievable stent, and wherein the plurality of electrodes is coupled to the compliant balloon.

13. The apparatus of claim 12, wherein the apparatus comprises a flexible substrate coupled to the compliant balloon and the plurality of electrodes.

14. The apparatus of claim 12, wherein, when the retrievable stent comprises the expanded configuration, the retrievable stent is configured to contact tissue of the heart such that the flexible elongate member is stationary relative to the heart, and wherein, when the compliant balloon comprises the expanded configuration, the compliant balloon is configured to cause the plurality of electrodes to conform to a shape of the interventricular septum.

15. The apparatus of claim 12, further comprising: an inflation lumen configured to provide an inflation fluid to the compliant balloon, and a plurality of electrical lines configured to provide the electrical energy to the plurality of electrodes, and a retention tube fixedly coupled to the push wire, and wherein the inflation lumen and the plurality of the electrical lines are received within the retention tube such that the retention tube is configured to allow relative longitudinal movement between: the retention tube; and the inflation lumen and the plurality of the electrical lines.

16. The apparatus of claim 15, wherein the retrievable stent, the compliant balloon, and the plurality of electrodes are coupled only at a distal portion of the retrievable stent, wherein the retrievable stent is configured to have a change in length during a transition from an unexpanded configuration to the expanded configuration, and wherein the change in length is configured to cause the relative longitudinal movement between: the retention tube; and the inflation lumen and the plurality of the electrical lines.

17. The apparatus of claim 1, wherein the at least one expandable member comprises a temporary valve configured to allow blood flow in a first direction and to prevent the blood flow in a second, opposite direction.

18. The apparatus of claim 1, further comprising a processor configured for communication with a pulsed field generator, wherein the processor is configured to activate the pulsed field generator to output the electrical energy to the plurality of electrodes such that the plurality of electrodes provide pulsed field ablation to the interventricular septum to trigger apoptosis in cells of the interventricular septum.

19. The apparatus of claim 18, further comprising the pulsed field generator.

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