ICE-optimized left atrial and left atrial appendage pacing

Abstract

A pacing system configured to sense cardiac activity and deliver pacing therapy to a patient's heart. A pacing system may include a first electrode configured to be positioned in a first chamber of a heart and configured to deliver a first pacing therapy to the first chamber of the heart and a second electrode configured to be positioned in a left atrial appendage and configured to deliver a second pacing therapy to the left atrial appendage. A processing module of the pacing system may be configured to time delivery of a first pacing therapy based on a first timing reference and time delivery of a second pacing therapy based on a determined pacing delay between the first pacing therapy and the second pacing therapy. The determined pacing delay may be configured to maximize blood flow into and / or out of the left atrial appendage.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 63 / 531,884, filed August 10, 2023, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates generally to implantable medical devices, and more specifically to implantable cardiac pacemakers. Background Technology

[0004] The left atrial appendage (LAA) is a small organ that attaches as a sac-like extension to the left atrium of the heart. In patients with atrial fibrillation, the LAA cannot contract properly with the left atrium, causing stagnant blood to pool within it, which can lead to unwanted thrombus formation within the LAA. Thrombi that form in the LAA can detach from the area and enter the bloodstream. Thrombi that migrate through blood vessels can eventually block smaller downstream vessels, leading to a stroke or heart attack. Clinical studies have shown that the majority of blood clots in patients with atrial fibrillation are found in the LAA. There is a continuing need for improved medical devices and methods for controlling thrombus formation in the LAA of patients with atrial fibrillation. Summary of the Invention

[0005] This disclosure provides design, materials, manufacturing methods, and alternatives for use in medical devices.

[0006] In a first example, a pacing system configured to sense cardiac activity and deliver pacing therapy to a patient's heart may include a first electrode configured to be positioned in a first chamber of the heart and configured to deliver a first pacing therapy to the first chamber of the heart, and a second electrode configured to be positioned adjacent to the left atrial appendage of the heart and configured to deliver a second pacing therapy to the left atrial appendage of the heart. A processing module of the pacing system may be configured to time the delivery of at least a portion of the first pacing therapy of the first electrode based at least in part on a first timing reference, and the processing module of the pacing system may be configured to time the delivery of at least a portion of the second pacing therapy of the second electrode based at least in part on a determined pacing delay between the first and second pacing therapies. The determined pacing delay may be configured to maximize blood flow into and / or out of the left atrial appendage.

[0007] As an alternative to or supplement to any of the above examples, in another example, the first electrode may be coupled to a first lead extending from the pacemaker and the second electrode may be coupled to a second lead extending from the pacemaker.

[0008] As an alternative to or supplement to any of the above examples, in another example, the second lead may include a puncture needle, an adhesive growth pad, a second electrode, and an electrical conductor extending proximally from the second electrode.

[0009] As an alternative to or supplement to any of the above examples, in another example, the puncture needle and the adhesive growth pad may be configured to be punctured through the outer surface of the left atrial appendage and compressed against the outer surface of the left atrial appendage.

[0010] As an alternative to or supplement to any of the above examples, in another example, the first electrode may be coupled to a first lead extending from the pacemaker and the second electrode may be coupled to a leadless cardiac pacemaker.

[0011] As an alternative to or supplement to any of the above examples, in another example, the pacemaker may communicate with a leadless cardiac pacemaker.

[0012] As an alternative to or supplement to any of the above examples, in another example, the first timing reference may include heart sounds.

[0013] As an alternative to or supplement to any of the above examples, in another example, the first timing reference may include a lobe opening.

[0014] As an alternative to or supplement to any of the above examples, in another example, the first timing reference may include a voltage drop.

[0015] As an alternative to or supplement to any of the above examples, in another example, the determined pacing delay can be configured to be customized during the implantation of the pacing system.

[0016] As an alternative or supplement to any of the above examples, in another example, the first chamber of the heart may be the left atrium.

[0017] As an alternative to or supplement to any of the above examples, in another example, the second electrode may be configured to be positioned in the left atrial appendage.

[0018] As an alternative to or supplement to any of the above examples, in another example, the second electrode may be configured to be positioned outside the left atrial appendage.

[0019] As an alternative to or supplement to any of the above examples, in another example, the determined pacing delay may be based on a first timing reference.

[0020] As an alternative to or supplement to any of the above examples, in another example, the determined pacing delay may be based on the first pacing therapy.

[0021] In another example, a method for implanting a pacing system may include delivering a first electrode to a first chamber of the heart, delivering a second electrode to the left atrial appendage of the heart, positioning an echocardiographic system to measure blood flow into and / or out of the left atrial appendage of the heart, delivering a first pacing therapy to the first chamber of the heart, delivering a second pacing therapy to the left atrial appendage of the heart, delivering the second pacing therapy for a period of time after the first pacing therapy, measuring blood flow into and / or out of the left atrial appendage while delivering the first and second pacing therapies, repeatedly delivering the first pacing therapy to the first chamber of the heart, delivering the second pacing therapy to the left atrial appendage of the heart, and measuring blood flow into and / or out of the left atrial appendage, while changing the time period between the first and second pacing therapies with each iteration of the pacing therapy, selecting an operable time period between the first and second pacing therapies that maximizes blood flow into and / or out of the left atrial appendage, and using the operable time period between the first and second pacing therapies to deliver the pacing therapy to the heart.

[0022] As an alternative to or supplement to any of the above examples, in another example, the following operations may be performed during the implantation of the first and second electrodes: repeatedly delivering a first pacing therapy to the first chamber of the heart, delivering a second pacing therapy to the left atrial appendage of the heart and measuring blood flow into and / or out of the left atrial appendage, while varying the time interval between the first and second pacing therapies with each iteration of the pacing therapy.

[0023] As an alternative to or supplement to any of the above examples, in another example, the operable time period between the first pacing therapy and the second pacing therapy may be stored in a processing module that communicates with the first and second electrodes.

[0024] As an alternative to or supplement to any of the above examples, in another example, changing the time interval between the first pacing therapy and the second pacing therapy may include incrementally increasing that time interval.

[0025] As an alternative to or supplement to any of the above examples, in another example, the timing of the first pacing therapy may be at least partially based on a first timing reference.

[0026] As an alternative to or supplement to any of the above examples, in another example, the time interval between the first pacing therapy and the second pacing therapy may be at least partially based on a first timing reference.

[0027] As an alternative to or supplement to any of the above examples, in another example, the following operations may be performed during the configuration mode: repeatedly delivering a first pacing therapy to the first chamber of the heart, delivering a second pacing therapy to the left atrial appendage of the heart and measuring blood flow into and / or out of the left atrial appendage, while changing the time interval between the first and second pacing therapies with each iteration of the pacing therapy.

[0028] As an alternative to or supplement to any of the above examples, in another example, pacing therapy may be delivered to the heart during an operational time interval between the first and second pacing therapies in response to a predetermined detected condition.

[0029] As an alternative to or supplement to any of the above examples, in another example, the predetermined detected condition could be detected atrial fibrillation and / or detected blood pressure drop.

[0030] In another example, a method for implanting a pacing system may include delivering a first electrode to a first chamber of the heart, delivering a second electrode to the left atrial appendage of the heart, advancing an echocardiographic system adjacent to the left atrial appendage of the heart, ablating an area of ​​cardiac tissue between the first and second electrodes, delivering a first pacing therapy to the first chamber of the heart, delivering a second pacing therapy to the left atrial appendage of the heart, delivering the second pacing therapy for a period of time after the first pacing therapy, measuring blood flow into and / or out of the left atrial appendage while delivering the first and second pacing therapies, repeatedly delivering the first pacing therapy to the first chamber of the heart, delivering the second pacing therapy to the left atrial appendage of the heart, and measuring blood flow into and / or out of the left atrial appendage, while changing the time period between the first and second pacing therapies with each iteration of the pacing therapy, selecting an operable time period between the first and second pacing therapies that maximizes blood flow into and / or out of the left atrial appendage, and using the operable time period between the first and second pacing therapies to deliver the pacing therapy to the heart.

[0031] As an alternative to or supplement to any of the above examples, in another example, pacing therapy can be delivered to the heart using an operational time interval between the first and second pacing therapies, occurring with each heartbeat.

[0032] In another example, a method of implanting a pacing system in the heart may include: a) detecting a first pacing reference; b) delivering a first electrode to the left atrial appendage of the heart after a delay following the pacing reference; c) advancing an echocardiographic system adjacent to the left atrial appendage of the heart; d) delivering a first pacing therapy to the left atrial appendage of the heart; e) measuring blood flow into and / or out of the left atrial appendage after the first pacing therapy; f) repeatedly delivering the first pacing therapy to a first chamber of the heart while varying the delay to identify a default delay associated with maximum flow; and g) configuring the pacing system including the first electrode using the default delay from the first pacing reference. Alternatively or additionally, in another example, the method may further include selecting a second pacing reference and repeating steps a), b), d), e), f), and g) using the second pacing reference instead of the first pacing reference.

[0033] As an alternative to or supplement to any of the above examples, in another example, the method may further include ablation of the area of ​​cardiac tissue adjacent to the left atrial appendage.

[0034] In any of the foregoing examples, “flow” or “blood flow” may be measured or parameterized as, for example, but not limited to, flow velocity, peak velocity, average velocity, flow rate, ejection fraction, or other suitable and relevant parameters. Additionally, in any of the foregoing examples, echocardiography may include, but is not limited to, intracardiac echocardiography (ICE), transesophageal echocardiography (TEE), and transthoracic echocardiography (TTE), and may be performed during or after implantation of the pacing system and used to optimize pacing delay or other aspects of the device or method.

[0035] The above summary of some embodiments is not intended to describe every embodiment or every implementation of this disclosure. The following drawings and detailed description illustrate these embodiments in more specific terms. Attached Figure Description

[0036] This disclosure can be understood more fully by considering the following detailed description of various embodiments taken in conjunction with the accompanying drawings, in which:

[0037] Figure 1 It is a partial cross-sectional view of certain elements of the heart and some adjacent blood vessels;

[0038] Figure 2 This is an illustrative diagram of a leadless cardiac pacemaker (LCP);

[0039] Figure 3 This is a schematic diagram of another type of medical device (MD);

[0040] Figure 4 It is a graphical representation of an illustrative electrocardiogram (ECG) that shows the time relationship between the electrical signals of the heart and the mechanical indications of heart contraction;

[0041] Figure 5 It is a floor plan illustrating a medical equipment system;

[0042] Figure 6 This is a floor plan of another illustrative medical system;

[0043] Figure 7 This is a floor plan of another illustrative medical system;

[0044] Figure 8 It is a schematic cross-sectional view of the heart equipped with implantable medical devices and an illustrative intracardiac echocardiography system;

[0045] Figure 9A This is a schematic diagram of the illustrative device stimulation protocol;

[0046] Figure 9B It is a schematic curve of flow rate relative to the pacing delay of the pacing system; and

[0047] Figures 10A-10C A schematic diagram depicts an alternative illustrative lead delivered to the left atrial appendage.

[0048] While various modifications and alternatives are possible to the various aspects of this disclosure, their specific details have been shown by way of example in the accompanying drawings and will be described in detail. However, it should be understood that this disclosure is not intended to limit the various aspects to the specific embodiments described. Rather, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of this disclosure. Detailed Implementation

[0049] The following description should be read with reference to the accompanying drawings, which are not necessarily to scale, wherein the same reference numerals indicate the same elements throughout in multiple views. The detailed description and drawings are intended to illustrate, but not limit, the claimed disclosure. Those skilled in the art will recognize that the various elements described and / or shown can be arranged in various combinations and configurations without departing from the scope of this disclosure. The detailed description and drawings illustrate exemplary embodiments of the claimed disclosure. However, for the benefit of clarity and ease of understanding, although each feature and / or element may not be shown in every drawing, one or more features and / or one or more elements may be understood to be present in any way unless otherwise specified.

[0050] The following definitions shall apply to terms unless otherwise defined in the claims or elsewhere in this specification.

[0051] All numerical values ​​are assumed herein to be modified by the term "about," whether explicitly stated or not. In the context of numerical values, the term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the stated numerical value (e.g., having the same function or result). In many cases, the term "about" may include numbers rounded to the nearest significant figure. Other uses of the term "about" (e.g., in contexts other than numerical values) may be assumed to have their common and customary definitions, as understood and consistent with the context of the specification, unless otherwise specified.

[0052] The range of values ​​recorded by endpoints includes all numbers in that range, including the endpoints (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0053] Although some suitable dimensions, ranges and / or values ​​relating to various components, features and / or specifications are disclosed, those skilled in the art will understand, inspired by this disclosure, that desired dimensions, ranges and / or values ​​may deviate from those explicitly disclosed.

[0054] As used in this specification and the appended claims, the singular forms “a,” “an,” and “this” include plural references unless explicitly stated otherwise. As used in this specification and the appended claims, the term “or” is generally used to mean “and / or” unless explicitly stated otherwise. Note that, for ease of understanding, certain features of this disclosure may be described in the singular, although these features may be plural or repeated within the disclosed embodiments. Each instance of a feature may include and / or be covered by the singular disclosure unless explicitly stated otherwise. For simplicity and clarity, not all elements of this disclosure are necessarily shown in every figure or discussed in detail below. However, it will be understood that the following discussion can be equally applied to any and / or all components in which more than one exists, unless explicitly stated otherwise. Additionally, for clarity, not all instances of certain elements or features may be shown in each figure.

[0055] Relative terms such as “proximal,” “distal,” “advance,” “retract,” and their variations can generally be considered relative to the positioning, orientation, and / or operation of various elements of the device by the user / operator / manipulator, where “proximal” and “retract” indicate or refer to proximity to or toward the user, and “distal” and “advance” indicate or refer to further away from or away from the user. In some instances, the terms “proximal” and “distal” may be arbitrarily assigned to facilitate an understanding of this disclosure, and such instances will be apparent to those skilled in the art. Other relative terms, such as “upstream,” “downstream,” “inflow,” and “outflow,” refer to the direction of fluid flow within a lumen (such as a body lumen or blood vessel) or within the device.

[0056] Please note that references to "one embodiment," "some embodiments," "other embodiments," etc., in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but each embodiment does not necessarily include that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Additionally, when a specific feature, structure, or characteristic is described in connection with an embodiment, whether explicitly described or not, implementing that specific feature, structure, or characteristic in conjunction with other embodiments will be within the knowledge of those skilled in the art, unless explicitly stated otherwise. That is, the various individual elements described below, even if not explicitly shown in a specific combination, are contemplated as being able to be combined with or arranged with each other to form other additional embodiments or to supplement and / or enrich the described embodiments, as understood by those skilled in the art.

[0057] For clarity, certain identifying numerical notation (e.g., first, second, third, fourth, etc.) may be used throughout the specification and / or claims to name and / or distinguish various described and / or claimed features. It should be understood that the numerical notation is not intended to be restrictive and is merely exemplary. In some embodiments, for the sake of brevity and clarity, modifications and deviations from the previously used numerical notation may be made. That is, a feature identified as a “first” element may later be referred to as a “second” element, a “third” element, etc., or may be omitted entirely, and / or different features may be referred to as a “first” element. The meaning and / or name in each instance will be obvious to a skilled practitioner.

[0058] A normal, healthy heart induces contractions by conducting intrinsically generated electrical signals throughout the heart muscle. These intrinsic signals cause the heart's muscle cells or tissues to contract in a coordinated manner. These contractions force blood in and out of the heart, providing circulation to the rest of the body. Many patients suffer from cardiac conditions that affect the effective functioning of their heart. For example, some hearts develop diseased tissue that no longer generates or effectively conducts intrinsic electrical signals. In some examples, the diseased cardiac tissue can conduct electrical signals at different rates, resulting in asynchronous and inefficient contractions of the heart. In other examples, the heart can generate intrinsic signals at such a low rate that the heart rate becomes dangerously low. In still other examples, the heart can generate electrical signals at abnormally high rates, even leading to tachycardia or fibrillation. In some cases, such abnormalities can develop into a fibrillation state, where the patient's ventricular contractions are almost completely desynchronized and the heart pumps little or no blood. Implantable medical devices (such as pacemakers) that can be configured to detect the occurrence of such cardiac abnormalities or arrhythmias and deliver one or more types of electrical stimulation therapy to the patient's heart can help terminate or alleviate these and other cardiac conditions.

[0059] Thrombosis in the left atrial appendage (LAA) during atrial fibrillation may result from stagnation of blood pooling within the LAA. While pooled blood can still be pulled out of the left atrium by the left ventricle, this is less effective due to the irregular contractions of the left atrium caused by atrial fibrillation. Therefore, instead of active support for blood flow from the contracting left atrium and LAA, ventricular filling may depend primarily or solely on the suction effect generated by the left ventricle. However, LAA contraction may be out of sync with the left ventricular cycle. For example, LAA contraction may be up to 180 degrees out of phase with the left ventricle, which can significantly impede desired blood flow. Furthermore, most LAAs are geometrically complex and highly variable, with large irregular surface areas and narrow orifices or openings relative to their depth. These aspects, alone or in various combinations, along with others, can contribute to high flow resistance to blood outflow from the LAA.

[0060] To reduce the occurrence of thrombus formation in the left atrial appendage (LAA) and prevent thrombi from entering the bloodstream from the LAA, it is desirable to develop medical devices and / or systems that increase the contractility of the LAA and / or increase blood flow into and / or out of the LAA, thereby resulting in less congestion and thrombus formation within the LAA. This article discloses example medical devices and / or systems that increase the contractility of the LAA and / or increase blood flow into and / or out of the LAA.

[0061] Figure 1This is a partial cross-sectional view of certain elements of the heart 10 and some adjacent blood vessels. The heart 10 may include a left ventricle 12, a right ventricle 14, a left atrium 16, and a right atrium 18. An aortic valve 22 is located between the left ventricle 12 and the aorta 20. A pulmonary or semilunar valve 26 is located between the right ventricle 14 and the pulmonary artery 24. The superior vena cava 28 and the inferior vena cava 30 return blood from the body to the right atrium 18. A tricuspid valve 34 is located between the right atrium 18 and the right ventricle 14. A pulmonary vein 36 returns blood from the lungs to the left atrium 16. A mitral valve 32 is located between the left atrium 16 and the left ventricle 12. The left atrial appendage (LAA) 50 is attached to and in fluid communication with the left atrium 16.

[0062] Figures 2-3 An illustrative implantable medical device is shown, and Figure 4 Illustrative ECG 300 and heart sound 302 signals are shown, with details of each and their temporal relationships. The following will discuss... Figures 2-4 A more detailed discussion is needed. For introductory purposes, it can be understood that... Figure 2 The diagram illustrates a leadless cardiac pacemaker (LCP) including an anchoring portion 116 that can be used to anchor the LCP in or on the heart, such as by attaching it to the heart wall. The LCP 100 includes electrodes 114, 114' that can be used to sense cardiac signals via an electrical sensing module 106 and processed by a processing module 110. In response to a sensed signal (or a non-sensed signal), a pulse generator module 104 uses power from a battery 112 to generate electrical pulses via the electrodes 114, 114' to pace the heart, causing myocardial contraction. In some illustrative examples, the LCP 100 may be implanted in, on, or adjacent to the cardiac artery (LAA) and used to induce blood flow from the LAA to prevent excessive blood pooling in the LAA, which can cause thrombosis. Figure 3 The diagram illustrates a pacemaker, again including an inductive module 206, a processing module 210, and a pulse generator module 204, which can be used to sense heart rhythm and generate pacing pulses via electrodes on one or more leads 214. In some illustrative examples, the leads are positioned in, on, or adjacent to the LAA and are used to induce blood flow from the LAA to prevent excessive blood pooling in the LAA, which can cause thrombosis.

[0063] Figures 5-7An illustrative medical device system is shown that can be configured to operate according to the techniques disclosed herein. Other example medical device systems may include additional or different medical devices and / or configurations. For example, other medical device systems suitable for operation according to the techniques disclosed herein may include additional LCPs implanted in the heart. Another example medical device system may include multiple LCPs without other devices such as the MD 200. In other examples, the configuration or placement of medical devices, leads, and / or electrodes may differ from... Figures 5-7 Those depicted in [the text]. Therefore, it should be recognized that, unlike [the text]... Figures 5-7 Many other medical device systems described herein can be operated according to the techniques disclosed herein. Therefore, Figures 5-7 The examples shown should not be considered as limiting in any way.

[0064] Figure 5 This is a plan view of the example MD 200, configured for implantation in the chest (or other location), with leads 212a and 212b implanted within or on the left atrium 16 and LAA 50. It is conceivable that the second lead 212b could be positioned distal to the LAA 50. However, this is not necessary. Other implantation sites can be used as needed. It is further conceivable that more than one lead can be attached to the left atrium 16 and / or to the LAA 50. It is further conceivable that additional leads can be attached to other parts of the heart 10. Figure 5 In the diagram, leads 212a and 212b are shown extending onto the tissue of the heart 10 to position one or more electrodes 214a and 214b within the myocardium. An epicardial approach for leads 212a and 212b is shown. Another approach could be leads 212c and 212d as shown, wherein the leads traverse the venous system to the right atrium 18, then pass through a transseptal puncture to the left atrium 16, and are anchored in the atrial wall adjacent to or within the LAA 50, rather than via epicardial implantation. This system can be configured to stimulate both the left atrium 16 and the LAA 50 to increase blood flow into and / or out of the LAA 50.

[0065] exist Figure 5In this system, pacing pulses can be delivered in various ways. If desired, a pacing pulse can be generated between electrodes 214a and 214b, creating an electric field over a relatively large area between them. Alternatively, at least electrode 214b can be a composite electrode, such as having a tip electrode and a ring electrode located a few millimeters proximal to the tip electrode, and a pacing pulse can be generated between the tip and the ring. In the case of composite electrode 214b, when the composite electrode is used to generate a pacing pulse, electrode 214a can be used to sense whether a biological signal is being transmitted (retrogradely) along the myocardium to the location of electrode 214a, and / or to determine the magnitude of any pacing artifacts at the location of electrode 214a. Both electrodes 214a and 214b can be composite electrodes, and pacing stimulation can be applied at both sites, for example, in a synchronous manner (e.g., simultaneously or with a set and / or adjustable delay between them). Other ways of using electrodes are discussed below.

[0066] Figure 6 This is a plan view of an example of LCP 100 implanted in LAA 50. Furthermore, in this example, a second MD 200 can be configured for implantation in the chest (or other location), with a transvenous lead 212d implanted within the left atrium 16; alternatively, an epicardial lead 212a can be implanted, or the left atrial lead can be omitted, as needed. It is conceivable that LCP 100 can be positioned distally to LAA 50. However, this is not necessary. Other implantation sites can be used within, above, or adjacent to LAA 50 as needed. It is further conceivable that more than one lead can be attached to the left atrium 16 and / or that more than one lead and / or more than one LCP 100 can be attached to LAA 50. It is further conceivable that additional leads can be attached to other parts of the heart 10. Although not explicitly shown, in some cases, LCP 100 can be implanted in contact with the outer surface of LAA 50. Figure 6 In the diagram, the lead 212a and fixation mechanism 116 of the LCP 100 are shown extending into the tissue of the heart 10 to position one or more electrodes 214a, 114 into the endocardial tissue. The system can be configured to stimulate both the left atrium 16 and the LAA 50 to increase blood flow into and / or out of the LAA 50.

[0067] Figure 7 This is a plan view of an example MD device 200 configured for implantation in the chest (or other location), wherein lead 212a or 212d is implanted within the left atrium 60 and lead 212b extends to the skeletal muscle 60 outside the nearby heart or LAA 50. Figure 7In the diagram, leads 212a or 212d are shown extending into the tissue of the heart 10 to position one or more electrodes 214a into the myocardium. Although not explicitly shown, additional leads from the MD 200 or LCP 100 may be positioned to contact the LAA 50. The system can be configured to stimulate both the left atrium 16 and the tissue adjacent to the LAA 50 to increase blood flow into and / or out of the LAA 50.

[0068] Further envisioning, the LCP 100 could be guided towards the heart 10, to the right atrium 18, via the inferior vena cava 30. The LCP could then be delivered to the LAA 50 via the septum. In other examples, the LCP could be delivered via the femoral route, without the need for the septal route. Visualization (such as through contrast injection) can be used to assist in LCP placement as needed. In some examples, Figures 5-7 The pacing system can omit the lead 212a extending to the left atrium 16. For example, the LAA 50 can be stimulated independently or in response to another pacing system.

[0069] Figures 5-7 The pacing system can be configured to deliver pacing pulses to the left atrium 16 and LAA 50 (or adjacent areas). In some cases, pacing therapy can be delivered sequentially to the left atrium 16 and LAA 50. For example, in some cases, the left atrium 16 may be stimulated by a first pacing therapy and the LAA 50 may be stimulated by a second pacing therapy after a predetermined delay period. It is conceivable that the delay between stimulation / pacing therapy can be selected to optimize or maximize blood flow into and / or out of the LAA 50. Blood flow into and / or out of the LAA 50 can be measured as flow velocity, peak velocity, mean velocity, flow rate, ejection fraction, etc. Echocardiography, including but not limited to intracardiac echocardiography (ICE), transesophageal echocardiography (TEE), and transthoracic echocardiography (TTE), can be performed during or after implantation of the pacing system and used to optimize the pacing delay between the left atrium 16 and LAA 50. For example, the pacing delay can be customized for each patient.

[0070] Figure 8 This is a schematic cross-sectional view of the heart 10 with an implanted MD 200 and an illustrative ICE system 400. Although Figure 8 This description pertains to the ICE system, but other echocardiographic systems, such as, but not limited to, TEE or TTE, may be used as needed. The ICE system 400 may include an elongated axis 402 (such as, but not limited to, a catheter axis) and an ultrasound device 404 disposed distal to the elongated axis 402. It is conceivable that, although not explicitly shown, the ICE system 400 may include other features such as manipulator lines, guide sheaths, etc. The ICE system 400 may be a radial or rotatable system or a phased array system, as needed.

[0071] The implanted MD 200 may include leads 212a and 212b implanted within the left atrium 16 and LAA 50. The transvenous leads are omitted from the diagram to allow for easier visualization of the ICE system 400; however, it should be understood that transvenous leads 212c and 212d, as shown above, could be used in place of the epicardial leads shown. Figure 8 In the diagram, leads 212a and 212b are shown extending into the tissue of the heart 10 to position one or more electrodes 214a and 214b into the endocardial tissue. It should be understood that, regarding... Figure 8 The described imaging and pacing time delay selection techniques can be applied to any of the pacing systems described herein. For example, pacing systems may include the MD 200 and LCP 100. After implantation of the MD 200, the ICE system 400 can be guided towards the heart 10, to the right atrium 18, via the inferior vena cava 30. When viewed from the patient's anterior side, the distal portion of the ICE system 400 may include a right-handed bend near its distal end, such that the ICE system 400 bends towards the wall (e.g., septum) between the right atrium 18 and the left atrium 16, although this is not necessary. The wall (septum) between the right atrium 18 and the left atrium 16 is punctured and the ICE system 400 is delivered through this wall to a location adjacent to the LAA 50. This is just one example. It is conceivable that, if necessary, the ICE system 400 can be delivered to the left atrium 16 using other routes.

[0072] Once the ICE system 400 is in place, the ultrasound device 404 can be positioned relative to the LAA and / or guided toward and activated towards the LAA. The ultrasound device 404 can emit high-frequency sound waves 406 toward the LAA 50. The sound waves 406 can be used, for example, to measure blood flow into and out of the LAA 50 via color Doppler, such as velocity, volume, and / or ejection fraction. Once the ICE system 400 is in place, the MD200 can be placed in a configuration mode. For example, a clinician can use a display or user input to select a configuration mode for the MD200. When more than one implantable device is provided, such as in... Figure 6In the system, each of the implantable devices 100 and 200 can be placed in a configuration mode. Once in configuration mode, the processing module 210 of the MD 200 can be configured to change the time delay between the delivery of pacing pulses at each lead (any of 212a, 212b, 212c, 212d and / or the electrode of the LCP 100), whether under the guidance of an external programmer or independently in automatic mode. In some cases, the processing module 210 can automatically change the time delay between the delivery of pacing pulses at each lead. In other examples, the processing module 210 can be configured to change the time delay between activations of each lead based on user input received at a display or user input.

[0073] See also Figure 9A The diagram illustrates a schematic curve 500 of an illustrative pacing device stimulation protocol, where a first lead can receive a first pacing therapy 502 at a first time point, and a second lead can receive the first pacing therapy 504 at a second time point. The second time point can be a first time length 506 after the first time point. It is conceivable that each lead can be activated once during a single heartbeat 508. However, it is not necessary to activate the leads with every heartbeat. It is further conceivable that the first lead can be activated in response to a predetermined timing reference. The time delay between the activation of the first lead and the activation of the second lead can be incrementally increased over a series of consecutive heartbeats. In other words, pacing therapy to the first lead and pacing therapy to the second lead can be repeatedly delivered while varying the time interval between pacing therapy sessions. It is conceivable that, as needed, the incremental increase can be a fixed amount of time or a varying amount of time, and can occur with each heartbeat / pacing output as needed, or can be changed every “N” heartbeats, where N can be 1, 2, 3, 4, 5, or a larger number. The first lead can have a second activation 510 at the third time point and the second lead can have a second activation 512 at the fourth time point. The fourth time point can be a second time length 514 after the third time point, and the second time length 514 is greater than the first time length 506.

[0074] While processing module 210 is adjusting the pacing delay between the first and second leads, ICE system 400 can determine and / or record the blood flow into and / or out of LAA 50 for each iteration of the pacing therapy (e.g., as peak velocity, average velocity, flow rate, ejection fraction, etc.). Processing module 210 or an external computing device can record the blood flow into and / or out of LAA 50 and the corresponding pacing delay. In some cases, blood flow and pacing delay can be recorded and / or displayed as... Figure 9BThe graph 550, table, or other data recording system shown. Graph 550 may show a curve 552 depicting the flow rate of blood flowing into and / or out of the LAA relative to the pacing time delay between the first and second leads. (See graph 550 for details.) Figure 9B As shown, the flow rate of blood flowing into and / or out of the LAA 50 can be maximized at a specific pacing time delay, such as... Figure 9B Line 554 is shown. Although Figure 9B Blood flow is shown as velocity, but other variables (such as, but not limited to, peak velocity, average velocity, flow rate, and ejection fraction) can be used to maximize or optimize blood flow from the LAA 50. Processing module 210 can be configured to store operable time intervals between pacing therapies or operable pacing time delays that maximize blood flow into and / or out of the LAA 50.

[0075] In some cases, processing module 210 (or an external computing device) can automatically determine and store the operable time interval between pacing therapies or the operable pacing time delay in which blood flow into and / or out of the LAA 50 is maximized. In other cases, the user can input the pacing time delay that maximizes blood flow into and / or out of the LAA 50 into the external computing device for relay to processing module 210 of MD 200. Processing module 210 can then automatically or in response to user input exit configuration mode and enter operating mode, and ICE system 400 can be removed from the body. It is conceivable that when more than one pacing device is provided, the operable time interval between pacing therapies or the operable pacing time delay can be provided to each processing module, or one of the pacing devices can be the dominant device issuing operating commands to one or more sub-devices.

[0076] Once in operating mode, processing module 210 can be configured to deliver pacing therapy using parameters determined during the configuration mode process. For example, a first lead may be activated in response to a determined pacing reference flag, and a second lead may be activated "x" seconds after the first lead. It is conceivable that the predetermined pacing time delay "x" can be in the range of milliseconds, for example, from 0.1 milliseconds to approximately 50 milliseconds.

[0077] In addition to maximizing blood flow into and / or out of the LAA 50, polarizing and / or depolarizing the LAA 50 at its distal sites can generate motion and / or instability, which can additionally reduce or prevent thrombosis. In some examples, the MD 200 can be configured to deliver pacing therapy in response to a predetermined condition. For example, the MD 200 may not pace the LAA with every heartbeat, which can prolong the lifespan of the MD 200. In some cases, the MD 200 can be configured to pace upon detection of atrial fibrillation. As mentioned above, when atrial fibrillation is detected, the LAA 50 may contract inappropriately and stagnant blood may pool within it. Delivering pacing energy to the left atrium 16 and the LAA 50 can increase the flow rate of blood entering and leaving the LAA 50 and increase its motion to reduce stagnation and thus reduce clots. In another example, pacing therapy can be delivered in response to pressure in the left atrium 16, the LAA 50, or other areas of the heart 10. For example, when higher pressure is present, less stimulation of atrial 16 and / or LAA 50 may be required. For example, the duty cycle of LAA pacing can vary as a function of one or more benchmarks, including the presence or absence of atrial fibrillation or atrial flutter, the presence or absence of sensed P waves (the absence of which can indicate undetected atrial fibrillation or flutter), intraatrial blood pressure above or below a threshold, the presence or absence of any other arrhythmias, the presence of irregular heart sounds, and the absence of the following: Figure 4 This includes any heart sound identified in the discussion. Multiple such conditions can be monitored. The duty cycle of LAA pacing can vary linearly or stepwise, as shown here:

[0078] For a standard P wave, the duty cycle for LAA pacing is 10%.

[0079] If no P wave is detected, the duty cycle of LAA pacing is 33%.

[0080] If atrial fibrillation is detected, the duty cycle of LAA pacing is 100%.

[0081] Other configurations can be used. In some examples, the pressure gradient in the left atrium can be detected to determine the pressure change from minimum to maximum left atrial pressure during the cardiac cycle. When the pressure gradient is relatively high, the duty cycle of LAA pacing can be relatively low (e.g., less than 50%), while when the pressure gradient is relatively low, the duty cycle of LAA pacing can be relatively high (e.g., more than 50%).

[0082] Pacing therapy applied to the LAA can utilize several different LAA pacing benchmarks. The LAA pacing benchmark used in this article is the event that triggers the LAA pacing output immediately or with a delay. Some examples can use the detection of the mitral valve 32 opening as an LAA pacing benchmark, such as by monitoring heart sounds, e.g., S3. In another example, the LAA pacing benchmark could be the detection of the S4 heart sound. Another LAA pacing benchmark could be the detection of atrial pressure drop, or the downward slope of atrial pressure. Yet another LAA pacing benchmark could be the detection of the pacing pulse by another implanted system, or the delivery of the pacing therapy by the same implanted system that issues the LAA pacing therapy. However, another LAA pacing benchmark could be an electrical event, such as the onset or peak of a P wave. In multiventricular pacing systems, for example, a lead with electrodes in the right atrium can detect the onset of right atrial depolarization (P wave onset), which can be used as a benchmark for LAA pacing.

[0083] Once the LAA pacing reference is detected, the LAA pacing pulse can be delivered immediately or after a predetermined delay. If both the LAA and left atrial pacing pulses are delivered separately, the LAA pacing reference can be used to trigger the first pacing output, followed by the other. In some examples, the configuration mode procedure described above can be performed using multiple different LAA pacing references, resulting in multiple different optimized LAA-to-left atrial pacing delays. For example, the LAA pacing system can be configured to use a detected mitral valve orifice event or a P wave detection in the right atrium as the pacing reference, and the delay to the first pacing pulse and the delay from the first pacing pulse to the second pacing pulse can be selected based on which LAA pacing reference triggers the pacing output.

[0084] It is conceivable that the area of ​​atrium 16 and / or LAA50 could be ablated before providing pacing therapy to atrium 16 and / or LAA50. For example, ablation could isolate LAA50 from the rest of the atrial neural pathway. This could isolate LAA50 from atrial fibrillation. However, ablation is not necessary. When ablation is performed, since LAA50 is isolated from the atrial neural pathway and does not receive intrinsically generated electrical signals from the heart 10, a pacing pulse can be provided with each heartbeat. Alternatively, after LAA has been electrically isolated from the cardiac nervous system, a pacing pulse can be provided at a duty cycle of less than 100% using, for example, any of the factors mentioned above for increasing or decreasing the duty cycle.

[0085] In another example, Figures 9A-9BThe diagram can be used in different approaches. Here, elements 502 and 510 can be understood as pacing benchmarks, i.e., the detected events used to trigger LAA pacing outputs at 504 and 512. Here, in this example, only one pacing output is generated, directly in the LAA. Then, the time delay from detecting pacing benchmarks 502 and 510 to issuing LAA pacing outputs at 504 and 513 is changed to create, for example... Figure 9B The graph shown can be used to determine the delay that maximizes the flow rate, which can then be selected as the delay from the pacing reference to the LAA pacing output. This method can be repeated for multiple different pacing references. Furthermore, if desired, the method can also be repeated for two pacing systems by first optimizing the delay from the pacing reference to the initial pacing output and then optimizing the delay between the two pacing outputs.

[0086] In some examples, conventional spiral leads may not be well-suited for use in the LAA 50. It is conceivable that in some examples, leads intended for use in the LAA 50 could be configured to extend through the LAA and be positioned on the outer surface of the LAA. Figures 10A-10C A schematic diagram depicts an alternative illustrative lead 600 being delivered to the LAA 50. Figure 10A In this process, the lead 600 is advanced to a target location within the delivery sheath 602. In the illustrated embodiment, the target location may be the wall 52 of the LAA 50. However, this is not necessary. This illustrative lead 600 can be used at other locations within the heart 10 as needed. It is conceivable that the delivery sheath 602 can be guided toward the heart 10 via the inferior vena cava 30, to the right atrium 18. The delivery sheath 602 may extend through a puncture in the septum between the right atrium 18 and the left atrium 16 to enter the LAA 50.

[0087] Once the delivery sheath 602 is near the target implantation site, the puncture needle 604 of the lead 600 can be advanced distally, beyond the distal end of the delivery sheath 602 and through the wall 52, as... Figure 10B As shown. An adhesive growth pad 606 can be positioned between the puncture needle 604 and the outer surface of the wall 52. The adhesive growth pad 606 can be configured to promote tissue growth to further fix the lead 600 relative to the tissue. An electrode 608 can be proximally spaced from the puncture needle 604 such that the electrode 608 contacts the endocardial tissue as the puncture needle 604 extends through the wall 52. A conductive member 610 can extend proximally from the electrode 608 to the pacing device. Finally, the lead 600 can be retracted proximally to radially expand the puncture needle 604 and compress the adhesive growth pad 606 against the tissue, as... Figure 10C As shown. The delivery sheath 602 and any other delivery aids can be retracted proximally from the body.

[0088] Another method is to access the chest through the intercostal space and advance the suture from its outer surface to a location adjacent to the LAA. This can be done using... Figures 10A-10C The above description of the center lead anchoring, but in which the placement system / conduit 602 is placed on the outside of the LAA.

[0089] The following is about Figures 2-4 A more detailed discussion is needed. Figure 2 This describes an illustrative leadless cardiac pacemaker (LCP) that can be implanted in a patient and can prevent, control, or terminate cardiac arrhythmias by, for example, with appropriate use of one or more therapies (e.g., anti-tachycardia pacing (ATP), cardiac resynchronization therapy (CRT), bradycardia therapy, or other antiarrhythmic therapies). Figure 2 As shown, LCP 100 can be a compact device, in which all components are housed within LCP 100 or directly on housing 120. Figure 2 In the example shown, LCP 100 may include a communication module 102, a pulse generator module 104, an electrical sensing module 106, a mechanical sensing module 108, a processing module 110, a battery 112, and electrodes 114. LCP 100 may include more or fewer modules, depending on the application.

[0090] The communication module 102 can be configured to communicate with devices located outside the LCP 100, such as sensors, other medical devices, and / or the like. Communication may use, for example, Bluetooth, Bluetooth Low Energy, Medradio, or other communication protocols, and appropriate circuitry including an antenna may be included in the communication module 102. Communication may replace or additionally utilize any of inductive coupling, optical, acoustic, and / or conducted signals, as known in the art. Communication can serve a variety of purposes, including allowing the LCP to be programmed by external devices, enabling the LCP to report device status and events to external devices, etc.

[0091] exist Figure 2 In the example shown, the pulse generator module 104 may be electrically connected to a plurality of electrodes 114 and / or 114'. The pulse generator module 104 may be configured to generate electrical stimulation signals, such as by means of appropriate circuitry including for modulating or multiplying a power signal obtained from battery 112, and the output may include, for example, pacing pulses or other therapeutic signals.

[0092] In some examples, LCP 100 may not include pulse generator module 104, in which case device 100 may be described as an implantable cardiac monitor. Device 100 may collect data on a patient's electrical activity and / or physiological parameters and transmit such data and / or determinations to one or more other medical devices via communication module 102.

[0093] In some examples, LCP 100 may include an electrical sensing module 106, and in some cases, a mechanical sensing module 108. The electrical sensing module 106 may be configured to sense the electrical activity of the heart. The mechanical sensing module 108 may include one or more sensors, such as an accelerometer, a blood pressure sensor, a heart sound sensor, a blood oxygen sensor, a temperature sensor, a flow sensor, and / or any other suitable sensors configured to measure one or more mechanical and / or chemical parameters of the patient. Both the electrical sensing module 106 and the mechanical sensing module 108 may be connected to a processing module 110, which can provide signals representing the sensed mechanical parameters. While regarding... Figure 2 Described as separate sensing modules, in some cases, the electrical sensing module 106 and the mechanical sensing module 108 may be combined into a single sensing module as needed. Other sensors, such as a pulse oximeter module, may be included as needed.

[0094] Processing module 110 can be configured to control the operation of LCP 100. For example, processing module 110 can be configured to receive electrical signals from electrical sensing module 106 and / or mechanical sensing module 108. Based on the received signals, processing module 110 can determine, for example, the occurrence of an arrhythmia and, in some cases, the type of arrhythmia. Based on any determined arrhythmia, processing module 110 can control pulse generator module 104 to generate electrical stimulation according to one or more therapies to treat the determined one or more arrhythmias. Processing module 110 can further receive information from communication module 102. In some examples, processing module 110 can use such received information to help determine whether an arrhythmia is occurring, determine the type of arrhythmia, and / or take a specific action in response to the information. Processing module 110 can additionally control communication module 102 to send information to / receive information from other devices.

[0095] In some examples, processing module 110 may include a pre-programmed chip, such as a very-large-scale integration (VLSI) chip and / or an application-specific integrated circuit (ASIC). In such embodiments, the chip may be pre-programmed with control logic to control the operation of LCP 100. By using a pre-programmed chip, processing module 110 can use less power than other programmable circuits (e.g., general-purpose programmable microprocessors) while still maintaining basic functionality, potentially increasing the battery life of LCP 100. In other examples, processing module 110 may include a programmable microprocessor. Such a programmable microprocessor allows the user to modify the control logic of LCP 100 even after implantation, allowing LCP 100 greater flexibility than when using a pre-programmed ASIC. In some examples, processing module 110 may further include memory, and processing module 110 may store information about the memory and read information from the memory. In other examples, LCP 100 may include a separate memory (not shown) communicating with processing module 110, such that processing module 110 can read information from and write information to the separate memory.

[0096] Battery 112 can provide power to LCP 100 for its operation. In some examples, battery 112 can be a non-rechargeable lithium-based battery. In other examples, the non-rechargeable battery can be made of other suitable materials as needed. Because LCP 100 is an implantable device, access to LCP 100 after implantation may be restricted. Therefore, sufficient battery capacity is desired to deliver therapy over treatment periods such as days, weeks, months, years, or even decades. In some instances, battery 112 can be a rechargeable battery, which can help increase the lifespan of LCP 100. In still other examples, battery 112 can be some other type of power source as needed.

[0097] To implant the LCP 100 into a patient, an operator (e.g., a physician, clinician, etc.) may secure the LCP 100 to the cardiac tissue of the patient's heart. For ease of securing, the LCP 100 may include one or more anchors 116. Anchors 116 may include any of a plurality of securing or anchoring mechanisms. For example, anchors 116 may include one or more pins, nails, threads, screws, spirals, teeth, and / or the like. In some examples, although not shown, anchors 116 may include threads on their outer surface that may extend at least a portion of the length of the anchor 116. These threads may provide friction between the cardiac tissue and the anchor to help secure the anchor 116 within the cardiac tissue. In other examples, anchors 116 may include other structures such as barbs, spikes, or the like to facilitate engagement with surrounding cardiac tissue.

[0098] Figure 3 Another example of a medical device (MD) 200 is depicted, which can be used alone or with an LCP 100 ( Figure 2 These modules can be used in combination to detect and / or treat arrhythmias and other cardiac conditions. In the example shown, MD 200 may include a communication module 202, a pulse generator module 204, an electrical sensing module 206, a mechanical sensing module 208, a processing module 210, and a battery 218. Each of these modules may be similar to modules 102, 104, 106, 108, and 110 of LCP 100. Additionally, battery 218 may be similar to battery 112 of LCP 100. In some examples, MD 200 may have a larger volume within housing 220 than LCP 100. In such examples, MD 200 may include a larger battery and / or a larger processing module 210 capable of handling more complex operations than processing module 110 of LCP 100.

[0099] While it is conceivable that the MD 200 could be another leadless device, such as Figure 2As shown, in some instances, the MD 200 may include leads such as lead 212. Lead 212 may include wires that conduct electrical signals between electrodes 214 and one or more modules located within the housing 220. In some cases, lead 212 may be connected to and extend away from the housing 220 of the MD 200. In some examples, lead 212 is implanted on, within, or near the heart of a patient. Lead 212 may include one or more electrodes 214 located at various locations on lead 212, and in some cases at various distances from housing 220. Some leads 212 may include only a single electrode 214, while others may include multiple electrodes 214. Typically, electrodes 214 are positioned on lead 212 such that when lead 212 is implanted in a patient, one or more of electrodes 214 are positioned to perform the desired function.

[0100] In some cases, one or more of the electrodes 214 may come into contact with the patient's cardiac tissue, such as by implanting a lead 212 by passing it through a blood vessel in the patient and either into a chamber of the heart (atrium or ventricle), or into a blood vessel in the heart where the lead can be anchored. In some cases, one or more electrodes 214 may be positioned substernally or subcutaneously but adjacent to the patient's heart, or in an epicardial location on the pericardium or the heart itself. In some cases, the electrodes 214 may conduct intrinsically generated electrical signals to the lead 212, for example, signals representing intrinsic cardiac electrical activity. The lead 212 may then conduct the received electrical signals to one or more of modules 202, 204, 206, and 208 of the MD 200. In some cases, the MD 200 may generate an electrical stimulation signal, and the lead 212 may conduct the generated electrical stimulation signal to the electrodes 214. The electrodes 214 may then conduct the electrical signal and deliver the signal to the patient's heart (directly or indirectly).

[0101] Similar to mechanical sensing module 108, mechanical sensing module 208 may include or be electrically connected to one or more sensors, such as an accelerometer, blood pressure sensor, heart sound sensor, blood oxygen sensor, acoustic sensor, ultrasound sensor, and / or other sensors configured to measure one or more mechanical / chemical parameters of the heart and / or a patient. In some examples, one or more of the sensors may be located on lead 212, but this is not required. In some examples, one or more of the sensors may be located within housing 220.

[0102] While not strictly necessary, in some examples, the MD 200 may be an implantable medical device. In such examples, the housing 220 of the MD 200 may be implanted, for example, in a patient's chest region. For instance, the pectoral muscle location or the axilla location may be the implantation site. The housing 220 can typically comprise any of many known materials that are safe for implantation in the human body and that, upon implantation, can seal the various components of the MD 200 from the fluids and tissues of the patient's body.

[0103] In some cases, the MD 200 may be an implantable cardiac pacemaker (ICP). In this example, the MD 200 may have one or more leads, such as lead 212, which are implanted on or inside the patient's heart. The one or more leads 212 may include one or more electrodes 214 in contact with the cardiac tissue and / or blood of the patient's heart. The MD 200 may be configured to sense intrinsically generated electrocardiographic signals and determine, for example, one or more arrhythmias based on analysis of the sensed signals. The MD 200 may be configured to deliver CRT, ATP therapy, bradycardia therapy, and / or other therapy types in conjunction with the LCP via the implanted lead 212 or by commanding LCP pacing. In some examples, the MD 200 may also be configured to provide defibrillation therapy.

[0104] In some instances, the MD 200 may be an implantable cardioverter-defibrillator (ICD). In such examples, the MD 200 may include one or more leads implanted in the patient's heart. The MD 200 may also be configured to sense electrocardiographic signals, determine the occurrence of tachycardia based on the sensed signals, and may be configured to deliver defibrillation therapy in response to determining the occurrence of tachycardia.

[0105] It is conceivable that one or more LCP 100 and / or one or more MD 200 can be used in combination as an example medical device system. The various devices 100, 200 can communicate via various communication pathways, including using RF signals, inductive coupling, conductive coupling optical signals, acoustic signals, or any other signals suitable for communication. The system may further include and communicate with a display. The display may be a personal computer, tablet computer, smartphone, laptop computer, or other display as needed. In some instances, the display may include input devices for receiving input from a user. For example, the display may also include a keyboard, mouse, actuable (e.g., pressable) buttons, or a touchscreen display. These are merely examples.

[0106] Reference Figure 4 It will be understood that the human heart is controlled by electrical signals that pass through heart tissue and can be detected by implanted devices, such as, but not limited to, [other methods]. Figure 2 or Figure 3 100 for LCP and / or 200 for MD. Figure 4 This is a graphical representation of an illustrative electrocardiogram (ECG) 300 and mechanical signals 302, illustrated and labeled as heart sound signals, showing the temporal relationship between the electrical signals of the heart and the mechanical indications 302 of cardiac contraction (e.g., heart sounds). As can be seen in the illustrative ECG 300, the heartbeat includes a P wave, which indicates atrial depolarization associated with atrial contraction to load the ventricles. The QRS complex, including the Q wave, R wave, and S wave, represents ventricular depolarization, which is associated with ventricular contraction to pump blood to the body and lungs. The T wave indicates ventricular repolarization, preparing for the next heartbeat. For cardiac diseases, the timing of these individual events may be anomalous or abnormal, and the shape, amplitude, and / or timing of the various waves may differ from those shown. It will be understood that the ECG 300 can be detected by implanted devices, such as, but not limited to, implantable devices. Figure 2 or Figure 3 LCP 100 and / or MD 200.

[0107] Characteristics or events in ECG 300 may have associated events in mechanical signal 302. Mechanical responses are typically delayed because the heart needs some time to respond to electrical signals. It will be understood that heart sounds can be considered examples of mechanical indications of the heartbeat. Other illustrative mechanical indications may include, for example, endocardial acceleration or motion of the heart wall detected by an accelerometer in the LCP, acceleration or motion of the heart wall detected by an accelerometer in the SICD, pressure, pressure changes, or rates of pressure change in the heart chambers detected by a pressure sensor in the LCP or other implantable device, acoustic signals caused by heart motion detected by acoustic sensors (e.g., accelerometers, microphones, etc.), cardiac torsion detected by a gyroscope in the LCP or other implantable device, and / or any other suitable indication of the beating of the heart chambers.

[0108] Reference Figure 4 In some cases, a first heart sound, designated S1, may be produced by the vibration generated during ventricular systole due to the closure of the mitral and tricuspid valves; a second heart sound, designated S2, may be produced by the closure of the aortic and pulmonary valves; a third heart sound, designated S3, is an early diastolic sound caused by the rapid flow of blood from the right atrium to the right ventricle and from the left atrium to the left ventricle; and a fourth heart sound, designated S4, is a late diastolic sound corresponding to the late ventricular filling during active atrial systole. These are mechanical responses, which can typically be detected using various sensors, such as microphones, hydrophones, accelerometers, etc.

[0109] Because heart sounds are the result of the myocardium contracting or relaxing in response to an electrocardiographic signal, it will be understood that a delay typically exists between the electrocardiographic signal indicated by ECG 300 and the corresponding mechanical indication indicated in the example shown by heart sound trace 302. For example, the P wave of ECG 300 is the electrocardiographic signal that triggers atrial contractions of the heart. The S4 heart sound is the mechanical signal caused by atrial contractions. In some cases, this relationship between the P wave and the S4 heart sound can be used. For example, if one of these signals can be detected, their expected timing relationship can be used as a mechanism for searching for the other. For example, if the P wave can be detected, a window following the P wave can be defined and searched to help find and / or isolate the corresponding S4 heart sound. In some cases, the detection of both signals can be an indication of the increased confidence level in a detected atrial contraction. In some cases, the detection of either signal may be sufficient to identify an atrial contraction. The identification of atrial contractions can be used to identify a timing reference for atrial contractions (e.g., a timing marker for atrial contractions). Ventricular contractions can be identified using the QRS signal and the S1 heart sound in a similar manner. The identification of ventricular contractions can be used to identify timing references for ventricular contractions (e.g., timing markers for ventricular contractions).

[0110] It should be understood that this disclosure is merely illustrative in many respects. Changes may be made in detail, particularly in terms of shape, size, and arrangement of steps, without departing from the scope of this disclosure. To the extent appropriate, this may include using any of the features of one exemplary embodiment in other embodiments. The scope of this disclosure is, of course, defined by the language set forth in the appended claims.

Claims

1. A pacing system configured to sense cardiac activity and deliver pacing therapy to a patient's heart, the pacing system comprising: A first electrode, configured to be positioned in a first chamber of the heart and configured to deliver a first pacing therapy to the first chamber of the heart; A second electrode is configured to be located near the left atrial appendage of the heart and configured to deliver a second pacing therapy to the left atrial appendage of the heart. The pacing system's processing module is configured to time the delivery of at least a portion of a first pacing therapy to the first electrode based at least partially on a first timing reference, and the pacing system's processing module is configured to time the delivery of at least a portion of a second pacing therapy to the second electrode based at least partially on a determined pacing delay between the first and second pacing therapies; and The determined pacing delay is configured to maximize blood flow into and / or out of the left atrial appendage.

2. The pacing system according to claim 1, wherein, The first electrode is coupled to a first lead extending from the pacemaker and the second electrode is coupled to a second lead extending from the pacemaker.

3. The pacing system according to claim 2, wherein, The second lead includes: Puncture needle; Adhesive growth pad; The second electrode; and An electrical conductor extending proximally from the second electrode.

4. The pacing system according to claim 3, wherein, The puncture needle and the adhesive growth pad are configured to be punctured through the outer surface of the left atrial appendage and compressed against the outer surface of the left atrial appendage.

5. The pacing system according to claim 1, wherein, The first electrode is coupled to a first lead extending from the pacemaker and the second electrode is coupled to a leadless cardiac pacemaker.

6. The pacing system according to claim 5, wherein, The pacemaker communicates with the leadless cardiac pacemaker.

7. The pacing system according to any one of claims 1-6, wherein, The first timing reference includes heart sounds.

8. The pacing system according to any one of claims 1-6, wherein, The first timing reference includes the lobe opening.

9. The pacing system according to any one of claims 1-6, wherein, The first timing reference includes the voltage drop.

10. The pacing system according to any one of claims 1-7, wherein, The determined pacing delay is configured to be customized during the implantation of the pacing system.

11. The pacing system according to any one of claims 1-8, wherein, The first chamber of the heart is the left atrium.

12. The pacing system according to any one of claims 1-11, wherein, The second electrode is configured to be positioned in the left atrial appendage.

13. The pacing system according to any one of claims 1-11, wherein, The second electrode is configured to be positioned outside the left atrial appendage.

14. The pacing system according to any one of claims 1-13, wherein, The determined pacing delay is based on the first timing reference.

15. The pacing system according to any one of claims 1-13, wherein, The determined pacing delay is based on the first pacing therapy.

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