Electrode for an implantable medical device for stimulating a human or animal heart

Abstract

The present invention relates to an electrode (20) for an implantable medical device for stimulating a human or animal heart, the human or animal heart comprising a left ventricle (5) and a right ventricle (3). According to an aspect of the invention, the electrode (20) comprises a first electrode pole surface (201) and a second electrode pole surface (202) located in a distal tip region of the electrode (20), wherein the second electrode pole surface (202) is spatially separated from the first electrode pole surface (201) and is arranged proximally of the first electrode pole surface (201), wherein the first electrode pole surface (201) is designed and arranged for stimulating the left ventricle (5) and wherein the second electrode pole surface (202) is designed and arranged for stimulating the right ventricle (3).

Description

[0001] Applicant: BIOTRONIK SE & Co. KG

[0002] Electrode for an implantable medical device for stimulating a human or animal heart

[0003] The present invention relates to an electrode for an implantable medical device according to the preamble of claim 1 and to an implantable medical device comprising such an electrode according to claim 13.

[0004] Implantable medical devices for stimulating a human or animal heart can feature different functionalities. To give an example, a CRT-D device is designed and arranged to accomplish a cardiac resynchronization therapy and a defibrillation of the patient’s heart. Such a CRT- D device typically has three electrodes, namely a combined right ventricular defibrillation and stimulation electrode, a right atrial stimulation and sensing electrode and a left ventricular coronary sinus electrode. Some manufacturers like BIOTRONIK also offer a more complex right ventricular electrode that integrates the atrial sensing functionality into the right ventricular stimulation electrode. However, still in this case, two electrodes are necessary to be implanted in or at the patient’s heart. Thus, the solutions known from prior art require for a biventricular stimulation at least two ventricular electrodes. This requires a very big connecting block (header) of the stimulation generator of the implantable medical device being able to receive at least two, but typically even three electrode connectors. Such a big connecting block complicates the implantation of the implantable medical device.

[0005] If the implantable medical device is designed and arranged as a CRT-P device, i.e., a device for cardiac resynchronization therapy and pacing (but no defibrillation), the general setup is almost identical to the previously described CRT-D device. However, the CRT-P device does not comprise a defibrillation electrode. Nonetheless, CRT-P devices known from prior art typically require three distinct electrodes and an accordingly big connector block of the stimulation generator to connect these electrodes to the stimulation generator. If the implantable medical device is designed and arranged as a device for employing a two- chamber therapy, it is also necessary to implant two distinct electrodes into the patient’s heart. One electrode is guided into the right atrium, and the other is guided into the left ventricle. Both electrodes need to be connected with the stimulation generator, i.e., the implantable pulse generator. For this purpose, the implantable pulse generator typically comprises at least two connecting sockets. Like in case of a three-socket connecting box, this requires a significant amount of space.

[0006] As outlined above, prior art already teaches a specific variant of integrated electrodes that uses a proximal bipole for sensing electric signals in the patient’s right atrium. Then, this variant of the ventricular electrode already takes over the functionality of the atrial electrode. However, this electrode comprises a switch with two plugs to be able to be connected with a regular two-chamber stimulation system. Thus, the integration of the atrial electrode into the ventricular electrode does not alter the space requirement of the connector block of the stimulation generator.

[0007] It is an object of the present invention to provide an electrode for an implantable medical device for stimulating a human or animal heart that has a particular simple construction, allows an easy implantation in the heart and an easy implantation of a housing of an implantable medical device to which the electrode is connected.

[0008] This object is achieved with an electrode for an implantable medical device for stimulating a human or animal heart having the features of claim 1.

[0009] Such an electrode comprises a first electrode pole surface and a second electrode pole surface. Both the first electrode pole surface and the second electrode pole surface are located in a distal tip region of the electrode. The second electrode pole surface is a spatially separated from the first electrode pole surface. In addition, it is arranged proximally of the first electrode pole surface. The first electrode pole surface is configured to stimulate the left ventricle of a patient’s heart, wherein the second electrode pole surface is configured to stimulate the right ventricle of the patient’s heart. For the purpose of stimulating either the right ventricle or the left ventricle of the patient’s heart, the first electrode pole surface and the second electrode pole surface are spaced apart from each other such that they can stimulate the respective ventricle.

[0010] In an embodiment, a distance between a distal end of the second electrode pole surface and a proximal end of the first electrode pole surface lies in a range of from 1 mm to 30 mm, in particular from 2 mm to 25 mm, in particular from 3 mm to 20 mm, in particular from 4 mm to 15 mm, in particular from 5 mm to 10 mm. Such a distance between the first electrode pole surface and the second electrode pole surface is particularly appropriate to allow a stimulation of different cardiac regions by the first electrode pole surface and the second electrode pole surface if the electrode is implanted into the septum of the patient’s heart. Then, the first electrode pole surface can stimulate the left bundle branch, i.e., it can perform left bundle branch area pacing (LBBAP). Likewise, the second electrode pole surface can then stimulate the right bundle branch, i.e., it can perform right bundle branch area pacing (RBBAP).

[0011] The arrangement of the first electrode pole surface and the second electrode pole surface in the distal tip region of the electrode enables such a combined stimulation of the left bundle branch or the right bundle branch and therewith of the left ventricle and the right ventricle after having implanted the electrode in the septum of the patient’s heart. This significantly facilitates a biventricular stimulation with only a single electrode that can, additionally, be manufactured in very low-complex manner.

[0012] In an embodiment, the first electrode pole surface and the second electrode pole surface belong to a common electrode pole. Thus, the first electrode pole surface and the second electrode pole surface provide the same electric potential to the cardiac tissue surrounding the first electrode pole surface and the second electrode pole surface, but at different locations (i.e., at different impact sites). This configuration of the first and second electrode pole surfaces enables a unipolar stimulation of the left and right ventricle, for instance against a housing, as a counter electrode, of an implantable device comprising the electrode. As explained above, the electrode is particularly intended to be implanted into the septum of the patient’s heart. Then, it is particularly easy by such a configuration to stimulate the right ventricle and the left ventricle in a highly synchronous manner. Consequently, the electrode is particularly appropriate to provide a cardiac resynchronization therapy (CRT) to the patient’s heart.

[0013] In an embodiment, the first electrode pole surface and the second electrode pole surface are electrically connected in series. Then, the same electric current is provided to the first electrode pole surface and to the second electrode pole surface and can be transmitted from the first electrode pole surface to the surrounding tissue and from the second electrode pole surface to the surrounding tissue.

[0014] In an embodiment, the first electrode pole surface and the second electrode pole surface are connected in parallel. Then, the same voltage is present at the first electrode pole surface and at the second electrode pole surface.

[0015] In an embodiment, the first electrode pole surface and the second electrode pole surface form part of a single electrically conductive component, such as a conductive lead. However, the first electrode pole surface and the second electrode pole surface are separated from each other by a superficial layer made from an insulating material. In such an arrangement, the first electrode pole surface and the second electrode pole surface have the same potential. The insulating superficial layer prevents a direct current flow between the first electrode pole surface and the second electrode pole surface and ensures that the electric current from the first electrode pole surface and from the second electrode pole surface is guided into the surrounding cardiac tissue.

[0016] In an embodiment, the insulating material is chosen from the group consisting of silicone, diamond-like carbon (DLC), carbides, and parylenes. A parylene is a particularly appropriate material to cover a surface of an electrically conductive lead between the first electrode pole surface and the second electrode pole surface.

[0017] In an embodiment, the first electrode pole surface and the second electrode pole surface belong to different electrode poles. Thus, each of the electrode pole surfaces represents a different electrode pole in this embodiment. Then, the second electrode pole surface can act as counter electrode for the first electrode pole surface. This configuration of the first and second electrode pole surfaces enables bipolar stimulation and / or sensing. This facilitates sensing functionalities of the first electrode pole surface and the second electrode pole surface. Furthermore, a polarity of the first electrode pole surface and the second electrode pole surface can be changed so that a stimulation is possible by the first electrode pole surface and the second electrode pole surface in the temporal offset manner.

[0018] In an embodiment, the electrode comprises a further electrode pole that is designed as a ring electrode pole. In addition, the further electrode pole is located proximally of the second electrode pole surface. In such an arrangement, the further electrode pole can be used as counter electrode for the first electrode pole surface and / or the second electrode pole surface. If no such further electrode pole is present, the electrode can be operated as unipolar electrode, wherein the housing of an implantable medical device to which the electrode is connected is used as counter electrode for the first electrode pole surface and the second electrode pole surface.

[0019] The precedingly explained embodiment with a further electrode pole can be realized both in case of the first electrode pole surface and the second electrode pole surface belonging to the same electrode pole and in case the first electrode pole surface and the second electrode pole surface belonging to different electrode poles.

[0020] In an embodiment, the first electrode pole surface and the second electrode pole surface are separated from each other by an insulating material and belong to different electrode poles. Appropriate insulating materials are the insulating materials referred to above.

[0021] In an embodiment, the first electrode pole surface and / or the second electrode pole surface is located on a helix that is configured to be secured within cardiac tissue. In this embodiment, the first electrode pole surface and the second electrode pole surface form part of a helical electrode pole. A helical arrangement of the electrode pole facilitates the fixing of the electrode pole within cardiac tissue such as the septum of the patient’s heart. A helical pole can be screwed into the cardiac tissue in which is to be secured, wherein the helical design ensures a tight fit of the electrode pole within the cardiac tissue.

[0022] In an embodiment, the helical electrode pole is designed as a helix welded onto the outer surface of an electrically conductive lead forming part of the electrode. In an embodiment, the electrode comprises a shock coil located proximally of the second electrode pole surface. Such a shock coil makes it possible to provide a defibrillation shock to the right ventricle of the patient’ s heart. Furthermore, the shock coil can be used as counter electrode for the first electrode pole surface and / or the second electrode pole surface. This embodiment can also be well combined with an embodiment in which the electrode comprises a further electrode that is designed and arranged as ring electrode. If both the ring electrode and the shock coil are present, the shock coil is typically located proximally of the ring electrode (and still proximally of the second electrode pole surface). If both a ring electrode and a shock coil are present, the ring electrode typically serves as counter electrode for the first electrode pole surface and / or the second electrode pole surface. The shock coil then serves only for delivering defibrillation shocks to the patient’s heart.

[0023] In an embodiment, the shock coil has a surface of at least 150 mm2, in particular at least 175 mm2, in particular at least 200 mm2, in particular at least 225 mm2, in particular at least 250 mm2. Such a surface enables a sufficiently big shock pulse to be delivered by the shock coil to achieve an efficient cardiac defibrillation of the patient’s heart.

[0024] In an embodiment, the electrode comprises a first atrial electrode pole and a second atrial electrode pole. Both atrial poles are designed as ring electrode poles. In this context, the first atrial electrode pole and the second atrial electrode pole are designed and arranged such that one of the first atrial electrode pole and the second atrial electrode poles serves as counter electrode pole for the respective other atrial electrode pole. In addition, the first atrial electrode pole is located proximally from the second electrode pole surface. Furthermore, the second atrial electrode pole is located proximally from the first atrial electrode pole. If the electrode additionally comprises a further electrode (configured as ring electrode), the first atrial electrode pole is located proximally of this further electrode. Furthermore, if the electrode comprises a shock coil, the first atrial electrode pole is located proximally of the shock coil. These two additional atrial electrode poles form a bipolar electrode pole arrangement that is located proximally of the second electrode pole surface (or proximally of the ring electrode or proximally of the shock coil, respectively). Such an arrangement makes it is possible that the first atrial electrode pole and the second atrial electrode pole are located, in an implanted state of the electrode, in the right atrium of the patient’s heart. Then, the first atrial electrode pole and the second atrial electrode pole can sense atrial signals to be used for triggering a stimulation of the right ventricle and / or the left ventricle of the patient’s heart by the first electrode pole surface and / or the second electrode pole surface. Thus, all sensing and stimulation functionalities of an implantable medical device are integrated within a single electrode. This has the effect that lead-to-lead interactions between different electrode leads are completely omitted. Rather, a single electrode employing both sensing and stimulation functionalities enables a particularly safe operation of an implantable medical device and also enables a much easier implantation than in case of two or three different electrodes.

[0025] Preferably, the first and second atrial electrode poles forming the bipolar electrode pole arrangement are floating supported within the right atrium.

[0026] If the electrode is designed as a VDD electrode (i.e., an electrode enabling an implantable pulse generator to be operated in its VDD mode featuring ventricular stimulation, biventricular sensing, and a dual operational mode (inhibition and triggering)), it also enables a VAT operation, i.e., a ventricular stimulation after atrial sensing in an operational mode that allows only triggering. The stimulation of the ventricle of the basis of the atrial cardiac rhythm is a particularly physiologic possibility of employing ventricular stimulation. Due to the possibility of implanting the electrode within the (deep) septum of the patient’s heart, the implantation of the electrode is also particularly facilitated with respect to prior art systems requiring an additional coronary sinus electrode placed on an outside of the left ventricle.

[0027] In an embodiment, the electrode lead of the electrode has a diameter of equal to or smaller than 6 F, in particular equal to or smaller than 5 F, in particular equal to or smaller than 4 F. Such dimension of the electrode lead also facilitates the implantation of the whole electrode.

[0028] In an embodiment, the connector of the electrode is realized according to the DF4 standard. Such a design of the connector is particularly appropriate if the electrode is designed for CRT-D applications, i.e., if a shock coil is present on the electrode. In an embodiment, the connector of the electrode is realized according to the IS4 standard. Such a configuration of the connector is particularly appropriate if the electrode is intended to be used for CRT-P applications, i.e., if the further electrode pole designed as ring electrode pole is present on the electrode.

[0029] The integration of different electrode poles into one and the same electrode enhances the versatility of the electrode leads to a more complex construction of the electrode. To allow a particularly simple construction of the electrode, it comprises, in an embodiment, only a single electrode pole. Then, only a single electrode lead needs to be guided within an electrode body from a proximal end of the electrode to a distal tip of the electrode. Due to the first electrode pole surface and the second electrode pole surface, the electrode can still be effective at different stimulation sites, even if it comprises only a single electrode pole.

[0030] In an embodiment, the electrode comprises a connector having only a single connector contact. Such a connector can be designed in a particularly small way, thus facilitating implanting of the electrode. A connector having a single connector contact also requires much less space in a header of a housing of an implantable medical device so that the header and therewith the housing of the implantable medical device can be realized smaller than prior art housings and headers. This also facilitates implantation of an according housing of an implantable medical device.

[0031] In an aspect, the present invention relates to an implantable medical device for stimulating a human or animal heart. This implantable medical device comprises a stimulation unit configured to stimulate a human or animal heart. The implantable medical device furthermore comprises an electrode according to the preceding explanations. In this context, the electrode forms part of the stimulation unit of the implantable medical device.

[0032] In an embodiment, the electrode is the only electrode of the implantable medical device. Then, a particularly small and simple construction of the whole implantable medical device is possible and allows a safe biventricular stimulation with only a single electrode.

[0033] In an embodiment, the implantable medical device comprises a header having only a single electrode connector receiving socket (also referred to as electrode connecting port or simply connecting port). As explained above, the connector of the electrode can be designed in a particularly small way, e.g., having only a single electrode connecting port. Then, the electrode connector receiving socket of the header can also be designed with very small dimensions so that the space requirement of the overall implantable medical device is significantly reduced with respect to prior art devices.

[0034] In an embodiment, the implantable medical device comprises a processor and a memory unit. The memory unit comprises a computer-readable program that causes the processor to perform the step explained in the following when being executed on the processor.

[0035] The performed step comprises providing an anti-tachycardic therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface. Alternatively or additionally, the step comprises providing a cardiac resynchronization therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface. Additionally or alternatively, the step comprises providing an anti- bradycardic therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface.

[0036] In an embodiment, the implantable medical device also comprises a sensing unit. This sensing unit comprises, in an embodiment, a sensing electrode being separate from the electrode described above. In another embodiment, the electrode described above also forms part of the sensing unit so that no separate sensing electrode is necessary.

[0037] In an embodiment, the computer-readable program causes the processor to sense, with the sensing unit, a cardiac signal of the same heart that is to be stimulated by the stimulation unit of the implantable medical device, if necessary. In an embodiment, the first electrode pole surface and / or the second electrode pole surface are used for sensing the cardiac electric signal. Then, the sensed cardiac electric signal is a ventricular signal. In another embodiment, the first atrial electrode pole and / or the second atrial electrode pole are used to sense the cardiac signal. Then, the cardiac signal is an atrial signal.

[0038] In an embodiment, the anti-tachycardic therapy, the cardiac resynchronization therapy and / or the anti-bradycardic therapy are provided in response to the sensed atrial cardiac signals so that the ventricular stimulation is triggered by the previously sensed atrial activity and is applied to the patient’s heart with a temporal delay with respect to the sensed atrial activity.

[0039] In an embodiment, the anti-tachycardic therapy comprises or consists of a defibrillation shock. In an embodiment, the implantable medical device is designed and arranged to provide, with its stimulation unit, a maximum shock energy of at least 30 J, in particular at least 40 J, in particular at least 50 J.

[0040] In an aspect, the present invention relates to a method for stimulating a human or animal heart using an implantable medical device according to the preceding explanations. The method comprises the following step: a) providing an anti-tachycardic therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface; and / or b) providing a cardiac resynchronization therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface; and / or c) providing an anti-bradycardic therapy by emitting an electric pulse by the first electrode pole surface and / or the second electrode pole surface.

[0041] In an aspect, the present invention relates to a method of implanting an implantable medical device according to the preceding estimations in a patient in need thereof. The method comprises the steps explained in the following.

[0042] In one method step, the electrode of the implantable medical device is guided into the right ventricle of the patient’s heart.

[0043] In another method step, a distal tip of the electrode is fixed within the septum of the patient’s heart or in the apex of the patient’s heart. This fixing is done such that the first electrode pole surface is located within the septum. The second electrode pole surface is also implanted such that it is located within the septum. Optionally, a further electrode pole and / or a shock coil are located in the right ventricle after implantation. Optionally, a first atrial electrode pole as well as a second atrial electrode pole are located, after implantation, in the right atrium of the patient’s heart. In another method step, the electrode is connected with its connector to a header of the housing of the implantable medical device. After this connection, the electrode forms part of the stimulation unit and optionally also of a detection unit of the implantable medical device.

[0044] In a further method step, the housing is implanted at an appropriate site outside the patient’s heart within the patient’s body. This is typically done in a pocket specifically provided for the implantable medical device, e.g., within the area of the patient’s clavicle, i.e., in a subclavian manner.

[0045] It is of no specific importance, in which order the precedingly mentioned implantation steps are performed. Therefore, the order of the present description is not to be construed in a limiting way.

[0046] The implantation of this implantable medical device is much easier than an implantation of the prior art devices since the electrode comprises only a single connector and the housing of the implantable medical device can be designed in a much smaller way than housings of prior art devices since the header of the implantable medical device only requires a single port for receiving the single connector of the electrode.

[0047] All embodiments of the electrode can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the implantable medical device and to the method. Likewise, all embodiments of the implantable medical device can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the electrode and to the method. Finally, all embodiments of the method can be combined in any desired way and can be transferred either individually or in any arbitrary combination to the electrode and to the implantable medical device.

[0048] Further details of aspects of the present invention will be explained in the following making reference to exemplary embodiments and accompanying Figures. In the Figures:

[0049] Fig. 1 shows a prior art CRT-D system implanted into a human heart; Fig. 2 shows an embodiment of a particularly simple biventricular electrode;

[0050] Fig. 3 shows a detail of another embodiment of a biventricular electrode;

[0051] Fig. 4A shows a detail of yet another embodiment of a biventricular electrode;

[0052] Fig. 4B shows a detail of yet another embodiment of a biventricular electrode;

[0053] Fig. 5 shows another embodiment of a biventricular electrode implanted into a human heart;

[0054] Fig. 6 shows another embodiment of a biventricular electrode implanted into a human heart;

[0055] Fig. 7 shows another embodiment of a biventricular electrode implanted into a human heart; and

[0056] Fig. 8 shows another embodiment of a biventricular electrode implanted into a human heart;

[0057] Figure 1 shows a human heart 1 comprising a right atrium 2, a right ventricle 3, a left atrium 4, and a left ventricle 5. A prior art device for cardiac resynchronization therapy and defibrillation (CRT-D device) 6 is implanted into the heart 1. This CRT-D device 6 comprises a stimulation generator 7 having a header 70. The header 70 comprises three header ports, each of which serves for receiving an individual electrode. Thus, the CRT-D device 6 comprises three electrodes, namely a right ventricular stimulation and shock electrode 8, a right atrial stimulation and sensing electrode 9, and a left ventricular stimulation and sensing electrode 10.

[0058] The right ventricular stimulation and shock electrode 8 is implanted into the right ventricle 3, wherein a tip 80 of the right ventricular stimulation and shock electrode 8 is placed close to the apex 11 or is implanted into the apex 11 of the patient’s heart 1. The right ventricular stimulation and shock electrode 8 furthermore comprises a shock coil 81 that is located proximally of the tip 80 of the right ventricular stimulation and shock electrode 8 and is situated, in the implanted state of the right ventricular stimulation and shock electrode 8, within the right ventricle 3.

[0059] The right atrial stimulation and sensing electrode 9 is implanted into the right atrium 2 and is secured within the cardiac tissue surrounding the right atrium 2. The left ventricular stimulation and sensing electrode 10 is guided into a coronary vein and placed outside the left ventricle 5 to be able to stimulate the left ventricle 5.

[0060] It is apparent from Figure 1 that the implantation procedure of the CRT-D device 6 is rather complicated. In addition, the header 70 of the stimulation generator 7 requires a significant amount of space to be able to house the three electrodes 8, 9, 10.

[0061] Figure 2 shows a human heart 1 into which a particularly simple biventricular unipolar electrode 20 is implanted. In this and in all following Figures, similar elements will be denoted with the same numeral reference.

[0062] The biventricular electrode 20 comprises a distal electrode pole surface 201 that serves as first electrode pole surface. It furthermore comprises a proximal electrode pole surface 202 that serves as second electrode pole surface. The proximal electrode pole surface 202 is located proximally of the distal electrode pole surface 201. The distal electrode pole surface 201 and the proximal electrode pole surface 202 form together a single electrode pole 203 that is implanted into the septum 13 of the patient’s heart 1. Since the distal electrode pole surface 201 and the proximal electrode pole surface 202 are spatially separated from each other, the distal electrode pole surface 201 is able to stimulate the left bundle branch of the patient’s heart 1, whereas the proximal electrode pole surface 202 is able to stimulate the right bundle branch of the patient’s heart 1.

[0063] To allow for a safe fixation of the electrode pole 203 within the septum 13 of the patient’s heart 1, the distal electrode pole surface 201 is designed as helix that is screwed into the septum 13 of the patient’s heart 1. The distal electrode pole surface 201 and the proximal electrode pole surface 202 are connected to the same electrode lead 204 that is guided within the electrode 20. At a proximal end of the electrode 20, the electrode lead 204 is connected in an electrical conductive manner with a connector pole 205 of a connector 206. Since the electrode 20 comprises only a single electrode lead 204, also only a single connector pole 205 is necessary. Consequently, the connector 206 of the electrode 20 comprises the connector pole 205 as the only connector pole.

[0064] As can be seen from Figure 2, the electrode 20 is guided through the upper vena cava 12 and through the right atrium 2 into the right ventricle 3. As explained above, the distal electrode pole surface 201 is screwed into the septum 13 from the right ventricle 3. Thus, the electrode 20 makes it possible to achieve a stimulation of the left ventricle 5 of the patient’s heart 1 without requiring direct access to the left ventricle 5 nor to an outside thereof.

[0065] Since the biventricular electrode 20 is a unipolar electrode, electric pulses emitted by the distal electrode pole surface 201 and / or the proximal electrode pole surface 202 use a housing of an implantable medical device, to which the biventricular electrode 20 is connected, as counter electrode.

[0066] Figure 3 shows a detail of the distal region of an embodiment of a biventricular electrode 20. The distal electrode pole surface 201 and the proximal electrode pole surface 202 are arranged on a helix that is screwed into the septum 13 of the patient’s heart. A superficial layer 207 is arranged in a region of the helix between the distal electrode pole surface 201 and the proximal electrode pole surface 202. This superficial layer 207 is made from a parylene and serves for an electrical insulation of the helix in the region in which it is applied onto the surface of the helix. Thus, due to the presence of the superficial layer 207, the helix is separated into the distal electrode pole surface 201 and the proximal electrode pole surface 202.

[0067] The electrode 20 is implanted into the septum 13 such that the distal electrode pole surface 201 is located closely to the left ventricular terminus 131 of the septum 13, whereas the proximal electrode pole surface 202 is located closely to the right ventricular terminus 132 of the septum 13. The biventricular electrode 20 further comprises a ring electrode 208 that is located proximally from the proximal electrode pole surface 202. This ring electrode 208 serves as counter electrode for the first electrode pole surface 201 and the second electrode pole surface 202. During operation of the biventricular electrode 20, the first electrode pole surface 201 and the second electrode pole surface 202 act typically as cathode, whereas the ring electrode 208 serves as anode.

[0068] Figure 4A shows a detail of the distal tip region of another embodiment of a biventricular electrode 20. Here, the distal electrode pole surface 201 is realized by a helix that is wound around an electrically conductive electrode lead 204 that also forms an electrode body of the biventricular electrode 20. Within the right atrium and the right ventricle of the patient’s heart, the electrode lead 204 is insulated by an insulation 209. This insulation 209 is, however, removed at the distal tip of the biventricular electrode 20, e.g., in the most distal 1.5 mm of the biventricular electrode 20. The helix forming the distal electrode pole surface 201 is welded onto an outer surface of the electrode lead 204.

[0069] The proximal electrode pole surface 202 is realized by a platinum sleeve that is crimped such onto the electrode lead 204 that it penetrates the insulation 209 and establishes an electric contact with the electrode lead 204. Consequently, the distal electrode pole surface 201 and the proximal electrode pole surface 202 form one and the same electrode pole 203 of the biventricular electrode 20.

[0070] In a preferred variant, shown in Figure 4B, of the biventricular electrode 20 shown in Figure 4A, an additional ring electrode 208 is disposed proximally of the second electrode pole surface 202. Similar to the embodiment of Figure 3, this ring electrode 208 serves as counter electrode for the first electrode pole surface 201 and the second electrode pole surface 202. During operation of the biventricular electrode 20, the first electrode pole surface 201 and the second electrode pole surface 202 act typically as cathode, whereas the ring electrode 208 serves as anode. The ring electrode 208 together with the first and second electrode pole surfaces 201 and 202 can be used for bipolar stimulation and / or sensing. In yet another variant of the of the biventricular electrode 20 shown in Figure 4A basically the same setup is used to provide a bipolar biventricular electrode 20. For such a bipolar variant of the electrode 20, the proximal electrode pole surface 202 is not electrically connected with the electrode lead 204, but rather contacts a different electrode lead (not shown in Figure 4) that also extends within the biventricular electrode 20 in an electrically insulated manner with respect to the electrode lead 204. Then, the proximal electrode pole surface 202 can be used as counter electrode for the distal electrode pole surface 201 for stimulating and / or sensing cardiac electric signals.

[0071] Figure 5 shows another embodiment of a biventricular electrode 20 that does not only comprise the distal electrode pole surface 201 and the proximal electrode pole surface 202 located within the septum 13 of the patient’s heart 1, but additionally a shock coil 210 that is located proximally of the proximal electrode pole surface 202. This shock coil 210 serves for providing a defibrillation shock to the patient’s heart 1 if necessary. In addition, it serves as counter electrode for the distal electrode pole surface 201 and the proximal electrode pole surface 202. Such a configuration can also be denoted as integrated bipolar configuration. It still enables the possibility of unipolar sensing and / or stimulation by the distal electrode pole surface 201 and the proximal electrode pole surface 202, if desired.

[0072] Figure 6 shows another embodiment in which not only the shock coil 210 is present on the biventricular electrode 20, but also a ring electrode pole 211 that is located between the shock coil 210 and the proximal electrode pole surface 202, i.e., proximally of the proximal electrode pole surface 202 and distally of the shock coil 210. This ring electrode pole 211 serves as counter electrode for the distal electrode pole surface 201 and the proximal electrode pole surface 202 so that it is not required that the shock coil 210 takes over this functionality. This configuration can also be denoted as true bipolar configuration.

[0073] Figure 7 shows another embodiment of a biventricular electrode 20 implanted into a patient’ s heart 1. This embodiment does not comprise the ring electrode pole 211 shown in the embodiment of Figure 6, but it comprises a first atrial electrode pole 212 and a second atrial electrode pole 213. The first atrial electrode pole 212 is located proximally from the shock coil 210, wherein the second atrial electrode pole 213 is located proximally from the first atrial electrode pole 212. The first atrial electrode pole 212 and the second atrial electrode pole 213 form an atrial bipole for sensing atrial signals.

[0074] The biventricular electrode 20 in this configuration can comprise a DF4 connector and enables a simultaneous left ventricular and right ventricular sensing and stimulation, wherein the timing of the stimulation is triggered by the sensed atrial signals. If required, the biventricular electrode 20 can also provide a defibrillation shock by the shock coil 210. Thus, it features of functionalities required for a CRT-D therapy while requiring only very small space due to its integrated construction and the use of a 4-pole connector that can be plugged into a corresponding 4-pole connector receiving section of a header of a housing of an implantable medical device (not shown in Figure 7). Thus, the electrode 20 according to this embodiment requires only a very small header.

[0075] Figure 8 shows another embodiment of a biventricular electrode 20 that combines the features of the embodiments shown in Figures 6 and 7. Briefly, the biventricular electrode 20 comprises - besides the distal electrode pole surface 201, the proximal electrode pole surface 202, and the shock coil 210 - both a ring electrode pole 211 and an atrial bipole comprising a first atrial electrode pole 212 and a second atrial electrode pole 213. The ring electrode 211 provides for a true bipolar derivation of intra cardiac signals. Consequently, the embodiment shown in Figure 8 can feature all the functionalities explained with respect to the embodiments shown in Figures 6 and 7. A 5-pole connector can be used for connecting this embodiment of the biventricular electrode 20 with a connector receiving portion of a header of a housing of an implantable medical device of which the bipolar electrode 20 forms part of.

Claims

Claims1. Electrode (20) for an implantable medical device for stimulating a human or animal heart, the human or animal heart comprising a left ventricle (5) and a right ventricle (3), characterized in that the electrode (20) comprises a first electrode pole surface (201) and a second electrode pole surface (202) located in a distal tip region of the electrode (20), wherein the second electrode pole surface (202) is spatially separated from the first electrode pole surface (201) and is arranged proximally of the first electrode pole surface (201), wherein the first electrode pole surface (201) is designed and arranged for stimulating the left ventricle (5) and wherein the second electrode pole surface (202) is designed and arranged for stimulating the right ventricle (3).

2. Electrode according to claim 1, characterized in that the first electrode pole surface (201) and the second electrode pole surface (202) belong to a common electrode pole (203), wherein the common electrode pole is particularly configured for unipolar stimulation of the left and right ventricle.

3. Electrode according to claim 2, characterized in that the first electrode pole surface (201) and the second electrode pole surface (202) are connected in series or in parallel.

4. Electrode according to claim 2, characterized in that the first electrode pole surface (201) and the second electrode pole surface (202) form part of a single electrically conductive component but are separated from each other by a superficial layer (207) from an insulating material.

5. Electrode according to claim 4, characterized in that the insulating material is chosen from the group consisting of silicone, diamond-like carbon, carbides, and parylenes.

6. Electrode according to claim 1, characterized in that the first electrode pole surface (201) and the second electrode pole surface (202) belong to different electrode poles and are, in particular, configured for bipolar stimulation.

7. Electrode according to any of the preceding claims, characterized in that the electrode (20) comprises a ring electrode pole as a further electrode pole and / or a shock coil, wherein the ring electrode is located proximally of the second electrode pole surface (202) and the shock coil is located proximally of the ring electrode and / or proximally of the second electrode pole surface (202).

8. Electrode according to any of the preceding claims, characterized in that at least one of the first electrode pole surface (201) and the second electrode pole surface (202) is located on a helix that is designed and arranged to be secured within cardiac tissue (13).

9. Electrode according to any of the preceding claims, characterized in that the electrode comprises a first atrial electrode pole (212) and a second atrial electrode pole (213) that are ring electrode poles, wherein the first atrial electrode pole (212) and the second atrial electrode pole (213) are designed and configured such that one of the first atrial and second atrial electrode poles (212, 213) serves as counter electrode pole for the respective other atrial electrode pole (213, 212), wherein the first atrial electrode pole (212) is located proximally from the second electrode pole surface (202) and wherein the second atrial electrode pole (213) is located proximally from the first atrial electrode pole (212).

10. Electrode according to the preceding claim, characterized in that the first and second atrial electrode poles form an atrial dipole that is configured for sensing atrial signals.

11. Electrode according to any of claims 1 to 5, characterized in that the electrode (20) comprises only a single electrode pole (203).

12. Implantable medical device for stimulating a human or animal heart, comprising a stimulation unit configured to stimulate a human or animal heart, characterized in that the implantable medical device comprises an electrode (20) according to any of the preceding claims, wherein the electrode (20) forms part of the stimulation unit.

13. Implantable medical device according to claim 12, characterized in that the implantable medical device comprises a header having only a single electrode connector receiving socket.

14. Implantable medical device according to claim 12 or 13, characterized in that the implantable medical device comprises a processor and a memory unit, wherein the memory unit comprises a computer-readable program that causes the processor to perform the following step when being executed on the processor: a) providing an anti-tachycardic therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202); and / or b) providing a cardiac resynchronization therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202); and / or c) providing an anti-bradycardic therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202).

15. Method for stimulating a human or animal heart using an implantable medical device according to any of claims 12 to 14, the method comprising the following step: a) providing an anti-tachycardic therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202); and / or b) providing a cardiac resynchronization therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202); and / or c) providing an anti-bradycardic therapy by emitting an electric pulse by the first electrode pole surface (201) and / or the second electrode pole surface (202).

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