Implantable medical device for stimulating a human or animal heart featuring a ventricular stimulation upon detection of a premature ventricular contraction

Abstract

The invention relates to an implantable medical device for stimulating a human or animal heart. The implantable medical device comprises at least one electrode (20, 21) that comprises a distal dipole (203) and is designed and arranged to be implanted within the septum (13) of the heart (1) to be stimulated. During operation, the implantable medical device performs the following steps: a) detecting, with the at least one electrode (20, 21), at least one of an intrinsic atrial signal and an intrinsic ventricular signal, or stimulating, with the at least one electrode (20, 21), the atrium (2) of the heart (1) to be stimulated; b) triggering a stimulation of the ventricle (5) of the heart (1) to be stimulated upon i) detecting the intrinsic atrial signal, ii) stimulating the atrium (2), or iii) detecting the intrinsic ventricular signal, wherein triggering upon i) detecting the intrinsic atrial signal or ii) stimulating the atrium (2) is carried out only with a predeterminable temporal delay, and triggering upon iii) detecting the intrinsic ventricular signal is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding ventricular signal, the first time period representing an allowable minimum ventricular interval.

Description

[0001] Implantable medical device for stimulating a human or animal heart featuring a ventricular stimulation upon detection of a premature ventricular contraction

[0002] The present invention relates to an implantable medical device according to the preamble of claim 1 and to a method for operating such a device according to the preamble of claim 10.

[0003] 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.

[0004] 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.

[0005] As outlined above, prior art already teaches a specific variant of integrated electrodes that uses a proximal dipole 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 box of the stimulation generator.

[0006] If the sensing and detecting functionalities of an implantable medical device are integrated into one or two electrodes, there remains the requirements of providing a patient with an optimum pacing adapted to the patient’s health status.

[0007] It is an object of the present invention to provide an implantable medical device that has a small space requirement, allows an easy implantation, and enables a comprehensive cardiac resynchronization therapy.

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

[0009] Such an implantable medical device comprises a processor, a memory unit, a stimulation unit, and a detection unit. The stimulation unit is arranged and designed to stimulate a human or animal heart. The detection unit is designed and arranged to detect an electric signal of the same heart. In addition, the implantable medical device comprises at least one electrode forming part of the stimulation unit and of the detection unit. What is special about the presently claimed and described implantable medical device is that the at least one electrode comprises a distal dipole and is configured to be implanted within the septum of the heart to be stimulated. At this implantation site, the distal dipole of the at least one electrode is able to stimulate at least the left ventricle of the patient’s heart by left bundle branch area pacing (LBBAP). Thus, the at least one electrode is able to bypass a left bundle branch block and thus to achieve an efficient pacing of the left ventricle even in case that the physiologic stimulus lines are no longer working or no longer working correctly.

[0010] The memory unit of the implantable medical device comprises a computer-readable program that causes the processor to perform the steps explained in the following when being executed on the processor.

[0011] In a first step, an intrinsic atrial signal and / or an intrinsic ventricular signal is detected with the at least one electrode (and the detection unit, the at least one electrode forms part of). Alternatively, the at least one electrode (and the stimulation unit, the at least one electrode forms part of) is used for stimulating the atrium of the heart to be stimulated. In a first aspect, the trigger event is the detection of the intrinsic atrial signal. Alternatively, the trigger event is the stimulation of the atrium. Alternatively, the trigger event is the detection of the intrinsic ventricular signal. In this context, the intrinsic ventricular signal is typically a right ventricular signal, whereas the triggered stimulation of the ventricle of the heart to be stimulated is typically a left ventricular stimulation. Thus, a right ventricular event is used for triggering a left ventricular stimulation. This is a particular appropriate possibility of achieving a cardiac resynchronization.

[0012] If detecting the intrinsic atrial signal or stimulating the atrium is used as trigger event, the triggering of the stimulation is carried out only after a predeterminable temporal delay. In doing so, the atrioventricular conduction time is mimicked. Consequently, the ventricular stimulation occurs only with a short delay after the atrial contraction so that a particularly physiologic stimulation of the heart is achieved. If a detection of the intrinsic ventricular signal is used as triggering signal, the triggering is carried out without temporal delay. As outlined above, the detected intrinsic ventricular signal is typically a right ventricular signal. In contrast, the applied ventricular stimulation is typically a left ventricular stimulation. By applying the left ventricular stimulation without temporal delay with respect to the detected right ventricular intrinsic stimulation, a resynchronization of both ventricles of the heart to be stimulated is achieved in a particularly appropriate way. To prevent the patient from a too rapid ventricular stimulation, the ventricular stimulation is triggered only if a predeterminable first time period has passed since a preceding, typically left, ventricular event. This predeterminable first time period represents an allowable minimum ventricular interval and can also be denoted as upper tracking interval.

[0013] Due to this protection mechanism based on actively preventing a too fast ventricular rate, (right) ventricular extrasystoles can be used as trigger events for providing a (left) ventricular stimulation of the heart to be stimulated. Expressed in other words, even a premature ventricular contraction can be used as trigger event for a cardiac resynchronization if the resulting ventricular rate remains below a predeterminable threshold that can be adjusted by setting the predeterminable first time period to a value that suits the needs of the patient who uses the implantable medical device. Thus, the cardiac resynchronization is no longer dependent only on atrial signals (either intrinsic or externally applied by the implantable medical device) but can rather rely on (premature) ventricular contraction events for achieving a cardiac resynchronization.

[0014] In an embodiment, the predeterminable temporal delay is a time period lying in a range of from 0.05 s to 0.25 s, in particular from 0.12 s to 0.22 s, in particular from 0.14 s to 0.20 s, in particular from 0.14 s to 0.18 s.

[0015] In an embodiment, the computer-readable program causes the processor to allow an activation and deactivation of the functionality implementing the triggering upon detecting the intrinsic ventricular signal. Thus, while the implantable medical device generally comprises this functionality, the functionality can be, in this embodiment, activated or deactivated according to the user’s needs. In an embodiment, the implantable medical device comprises a communication unit. This communication unit serves for receiving instructions from an external device, wherein the instructions relate to the activation and / or deactivation of the functionality implementing the triggering upon detecting the intrinsic ventricular signal. Then, it is possible to transmit according instructions (control signals) from a programming device or via remote programming to the implantable medical device. This enables a user-specific programming of the implantable medical device and thus enhances the versatility of the implantable medical device.

[0016] In an embodiment, the communication unit serves for transferring data to the processor in a wireless manner. All standard data transmission protocols or specifications are appropriate for such a wireless data communication. Examples of standard data transmission protocols or specifications are the Medical Device Radiocommunications Service (MICS), the Bluetooth Low Energy (BLE) protocol, the Zigbee specification, the long range wide area network (LoRaWAN) protocol, the wireless personal area network (WPAN) specification, the low-power wide-area network (LPWAN) specification, the wireless local area network (WLAN) specification, the Global System for Mobile Communications (GSM) specification, the Long-Term Evolution (LTE) standard, and the fifth-generation technology standard for broadband cellular networks (5G).

[0017] In an embodiment, the computer-readable program causes the processor to allow a separate activation and a separate deactivation of the functionality implementing the triggering upon detecting the intrinsic ventricular signal for different operational modes. In this context, the different operational modes are an atrial controlled operational mode and a ventricularly controlled operational mode of the implantable medical device. To give an example, if the implantable medical device is to be operated in an atrial controlled operational mode, no ventricular contraction is needed for triggering a ventricular stimulation. In such a case, the functionality implementing the triggering upon detecting the intrinsic ventricular signal is deactivated. In contrast, if the implantable medical device is to be operated in a ventricularly controlled operational mode, it is helpful to also use premature ventricular contractions as trigger for a cardiac resynchronization. In such a case, the functionality implementing the triggering upon detecting the intrinsic ventricular signal is typically activated.

[0018] In an embodiment, the implantable medical device necessarily comprises the functionality implementing a triggering of a ventricular stimulation upon detecting the intrinsic ventricular signal. In this embodiment, the other functionalities implementing a triggering of the ventricular stimulation upon detecting an intrinsic atrial signal or upon an atrial stimulation are only optional functionalities that are not necessarily implemented in the implantable medical device. In a further embodiment, all precedingly mentioned functionalities are necessarily present, wherein individual functionalities may be activated or deactivated according to the user’s needs.

[0019] In an embodiment, the intrinsic ventricular signal is a signal that originates from a ventricular extrasystole. Alternatively, the intrinsic ventricular signal is a signal that originates from a regular ventricular contraction. As explained above, an extrasystole can be well used as ventricular trigger signal for a subsequent ventricular stimulation since the requirement of passing of the first time period prevents a ventricular overstimulation and thus a too high cardiac rate.

[0020] In an embodiment, the predeterminable first time period is a time period lying in a range of from 0.3 seconds to 1.5 seconds, in particular from 0.4 seconds to 1.4 seconds, in particular from 0.5 seconds to 1.3 seconds, in particular from 0.6 seconds to 1.2 seconds, in particular from 0.7 seconds to 1.1 seconds, in particular from 0.8 seconds to 1.05 seconds, in particular from 0.9 seconds to 1.0 seconds.

[0021] In an embodiment, the computer-readable program causes the processor to allow a separate activation and a separate deactivation of the functionality implementing the triggering of the ventricular stimulation upon detecting the intrinsic ventricular signal depending on the origin of the intrinsic ventricular signal. Thus, the triggering functionality relying on an intrinsic ventricular signal originating from a ventricular extrasystole can be separately activated and deactivated from the functionality implementing a stimulation triggering in dependence on an intrinsic ventricular signal originating from a regular ventricular contraction. This embodiment allows a further fine-tuning of the operational modes of the implantable medical device and an even better adjustment of the functionalities of the implantable medical device according to the user’s needs.

[0022] The distal dipole comprises a first electrode pole and a second electrode pole located proximally from the first electrode pole. In an embodiment, a distance between the first and second electrode pole is adapted to a thickness of the septum of the patient’s heart., i.e. the first and second electrode poles have a distance from one another that enables a simultaneous stimulation of the left and right bundle branch when the distal dipole is implanted in the septum. In an implanted state of the distal dipole, the first and second electrode poles are completely incorporated into the septum, whereas the first electrode pole is disposed next to the left ventricle and the second electrode pole is disposed next to right ventricle. In an, embodiment, a distance between a distal end of the second electrode pole and a proximal end of the first electrode pole 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 and the second electrode pole is particularly appropriate to allow a stimulation of different cardiac regions, in particular the left and right bundle branches, by the first electrode pole and the second electrode pole after the electrode has been implanted into the septum of the patient’s heart. Then, the first electrode pole can stimulate the left bundle branch, i.e., it can perform left bundle branch area pacing (LBBAP). Likewise, the second electrode pole can then stimulate the right bundle branch, i.e., it can perform right bundle branch area pacing (RBBAP). In addition, the second electrode pole can particularly well detect right ventricular signals in this position.

[0023] Moreover, a dipole configured as such, and depending on the position of the dipole, allows a precise, and in particular also simultaneous, stimulation of the left and right bundle branch. In addition, the second electrode pole of the dipole can also detect right ventricular signals in this position.

[0024] In an embodiment, the implantable medical device comprises two electrodes (in particular exactly two electrodes). The first of these two electrodes is the electrode with the distal dipole. The second electrode of these two electrodes comprises an atrial dipole designed and arranged to detect the intrinsic atrial signal. In particular, the second electrode may be configured such that after implantation of the second electrode, the proximal dipole is implanted within the right atrial wall. In another embodiment, the second electrode is configured such that after implantation, the proximal dipole is not fixed within the atrium but acts as a floating dipole. In an embodiment, the atrial dipole can also be used for stimulating the atrium of the heart to be stimulated. Then, the electrode poles take over the functionalities of sensing atrial signals and providing atrial stimulation pulses.

[0025] In an embodiment, the implantable medical device comprises only a single electrode. This single electrode comprises - besides the distal dipole - a proximal dipole that is arranged and designed to detect the intrinsic atrial signal. After implantation of the single electrode of the implantable medical device, the distal dipole is implanted within the septum of the heart to be stimulated, wherein the proximal dipole is located within the right atrium of the heart, in particular as a floating dipole.

[0026] If the implantable medical device comprises only a single electrode, a housing of the implantable medical device also requires only a single electrode connector receiving socket. Thus, in an embodiment, a header of a housing of the implantable medical device has only a single electrode connector receiving socket. This reduces the space requirement of the housing and facilitates implantation of the housing and thus of the overall implantable medical device with respect to prior art devices. If only a single electrode connector receiving socket is present, an electrode connector cannot be inadvertently inserted into a wrong electrode connector receiving socket. Thus, the implantation of the implantable medical device is less error-prone than the implantation of prior art devices.

[0027] In an aspect, the present invention relates to a method for operating an implantable medical device according to the preceding explanations. This method comprises the steps explained in the following.

[0028] In a first step, an intrinsic atrial signal and / or an intrinsic, typically right, ventricular signal is detected with the at least one electrode (forming part of the detection unit) or the atrium of the heart to be stimulated is stimulated with the at least one electrode (forming part of the stimulation unit).

[0029] In a subsequent step, a stimulation trigger signal for a subsequent stimulation of the ventricle, typically being the left ventricle, of the heart to be stimulated is provided. In this context, the detection of the intrinsic atrial signal or the detection of the intrinsic ventricular signal or the stimulation of the atrium is used as trigger event decisive for the provision of the stimulation trigger signal. The stimulation trigger signal is provided only after a predeterminable temporal delay if the intrinsic atrial signal or the stimulation of the atrium is used as trigger event for providing the stimulation trigger signal. If the detection of the intrinsic ventricular signal is used as triggering event for providing the stimulation trigger signal, the stimulation trigger signal is provided immediately without temporal delay but only if a predeterminable first time period has passed since a preceding, typically left, ventricular event. This predeterminable first time period represents an allowable minimum ventricular interval.

[0030] The provided stimulation trigger signal is - in a time frame lying outside the claimed range of the method for operating the implantable medical device - guided through the electrode to the distal dipole and can then effect a ventricular stimulation of the heart to be stimulated.

[0031] In an aspect, the present invention relates to a method for providing a cardiac resynchronization therapy to a patient in need thereof. This method comprises the steps explained in the following.

[0032] First, an intrinsic, typically right, ventricular signal is detected with an electrode of an implantable medical device for stimulating a human or animal heart. An implantable medical device according to the preceding destinations is particularly appropriate for carrying out the presently claimed and described method. The electrode comprises a distal dipole and is implanted within the septum of the patient’s heart. At its implantation site, the electrode is able to stimulate the left bundle branch (i.e., it is able to provide LBBAP) and thus to stimulate the left ventricle of the patient’s heart. Upon detecting the intrinsic ventricular signal, a stimulation of the ventricle, typically being the left ventricle, of the patient’s heart is triggered. This triggering is carried out without temporal delay so as to resynchronize the ventricular activity of the left ventricle and the right ventricle of the patient’s heart. However, the stimulation is only triggered if a predeterminable first time period has passed since a preceding, typically left, ventricular event. The first time period represents an allowable minimum ventricular interval. Thus, the first time period serves as protection against a too high ventricular rate.

[0033] In an embodiment, the intrinsic ventricular signal is a signal that originates from a ventricular extrasystole. Alternatively, the intrinsic ventricular signal is a signal that originates from a regular ventricular contraction.

[0034] In an embodiment, the method additionally comprises detecting an intrinsic atrial signal or stimulating the atrium of the patient’s heart with a stimulation unit of the implantable medical device. In this embodiment, the method further comprises triggering the stimulation of the, typically left, ventricle of the patient’s heart upon detecting the intrinsic atrial signal or upon stimulating the atrium. In this context, the triggering is carried out only after a predeterminable temporal delay after having detected the intrinsic atrial signal or after having stimulated the atrium. In this embodiment, the method does not only allow a cardiac resynchronization triggered on a, typically right, (premature) ventricular excitation such as an extrasytole, but also allows an atrial triggering of a subsequent ventricular stimulation, wherein the atrial triggering is based on an intrinsic (physiologic) atrial signal or an applied atrial stimulation.

[0035] 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 each of the methods. Likewise, all embodiments of each of the methods 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 respective other method.

[0036] 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: Figure 1 shows a prior art CRT-D system implanted into a human heart;

[0037] Figure 2 shows an embodiment of an implantable medical device comprising a dipolar ventricular electrode and a dipolar atrial electrode implanted into a human heart;

[0038] Figure 3 shows a detail of another embodiment of an implantable medical device comprising only a single electrode implanted into a human heart;

[0039] Figure 4 shows a detail of another embodiment of an implantable medical device comprising only a single electrode implanted into a human heart; and

[0040] Figure 5 schematically shows different components of an embodiment of an implantable medical device.

[0041] 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.

[0042] 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. 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.

[0043] 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.

[0044] Figure 2 shows a human heart 1 into which a ventricular electrode 20 and an atrial electrode 21 are implanted. Both the ventricular electrode 20 and the atrial electrode 21 are guided through the upper vena cava 12 into the right atrium 2. The ventricular electrode 20 is furthermore guided into the right ventricle 3 and fixed within the septum 13 separating the right ventricle 3 from the left ventricle 5, in particular next to or within the left bundle branch. In this way, the ventricular electrode 20 is implanted in a deep septal position so that it can stimulate the left bundle branch of the human heart 1 and thus stimulate the left ventricle 5 even though it does not directly contact the left ventricle 5.

[0045] The atrial electrode 21 serves for detecting atrial signals and / or stimulating atrial tissue. For this purpose, the atrial electrode 21 comprises a first atrial electrode pole 211 and a second atrial electrode pole 212 that is located proximally of the first distal atrial electrode pole 211. The first atrial electrode pole 211 and the second atrial pole 212 form an atrial dipole 213 that is at least partially implanted into atrial tissue.

[0046] The ventricular electrode 20 comprises a first distal electrode pole 201 and a second distal electrode pole 202 that is located proximally of the first distal electrode pole 201. The first distal electrode pole 201 and the second distal electrode pole 202 form a distal dipole 203. The distal dipole 203 is fixed within the septum 13 of the patient’s heart 1.

[0047] The ventricular electrode 20 and the atrial electrode 21 form part of a CRT-P device 22 that represents an implantable medical device. The CRT-P device 22 comprises a stimulation generator 23 (also referred to as housing) that comprises a header 230. The header 230 is significantly smaller than the header 70 of the prior art stimulation generator 7 (confer Figure 1) since it only requires space for two electrode connector receiving sockets. The ventricular electrode 20 and the atrial electrode 21 are plugged into these electrode connector receiving sockets with their electrode connectors.

[0048] Figure 3 shows another embodiment of an ventricular electrode 20 that forms part of an implantable medical device for stimulating the human or animal heart. This ventricular electrode 20 comprises not only the first distal electrode pole 201 and the second distal electrode pole 202, but also the first atrial electrode pole 211 and the second atrial electrode pole 212 that both form together the atrial dipole 213. This atrial dipole 213 serves for detecting atrial signals within the right atrium 2 of the heart 1. By integrating the atrial dipole 213 into the ventricular electrode 20, it is not necessary to implant a separate atrial electrode like in case of the embodiment shown in Figure 2. This further facilitates the implantation procedure. In addition, the electrode 20 comprising both the ventricular dipole 203 and the atrial dipole 213 requires only a single electrode connector so that the header of a housing of an implantable medical device can be realized even smaller than in case of the embodiment shown in Figure 2.

[0049] Figure 4 shows another embodiment of the ventricular electrode 20 that forms part of an implantable medical device. In this embodiment, the ventricular electrode 20 comprises the same elements as the ventricular electrode 20 of the embodiment shown in Figure 3, but additionally a shock coil 210 that is located between the ventricular dipole 203 and the atrial dipole 213. This shock coil 210 enables the provision of a defibrillation shock to the heart 1 in case that not only a resynchronization, but also a defibrillation is required. Thus, the ventricular electrode 20 of the embodiment shown in Figure 4 is able to provide a CRT-D therapy. Expressed in other words, this ventricular electrode 20 forms part of a CRT-D system as example of an implantable medical device.

[0050] Figure 5 schematically illustrates individual components of an embodiment of an implantable medical device, such as of the embodiments shown in Figures 2 to 4, that are comprised within the stimulation generator 23 of the implantable medical device. The stimulation generator 23 houses a detection unit 231 (also referred to as sensing unit) that typically comprises an analog-to-digital converter, a bandpass filter, and an offset compensation. The detection unit 231 is operatively connected with a processor 232 that has access to a memory unit 233. The memory unit 233 serves for storing instructions for the processor 232 as well as data detected by the detection unit 231. The stimulation generator 23 further optionally comprises an evaluation unit 234 that can also be part of the processor 232 and that serves for extracting features from the detected cardiac electric signal. The stimulation generator 23 further comprises a stimulation unit 235 that serves for stimulating the heart from which the detection unit 231 detects electric signals. The ventricular electrode 20 and optionally the atrial electrode 21 (along with their electrode poles 201, 202, 211, and 212; confer Figures 2 to 4) form part of the detection unit 231 and of the stimulation unit 235. Additionally, the stimulation generator 23 comprises a communication unit 236 that serves for data transfer to a (remote) programming device.

[0051] In the following, an operation of an implantable medical device for stimulating a human or animal heart according the embodiment of figure 5 having an electrode configuration according to the embodiment of figure 3 is described. The computer-readable program stored in the memory unit 233 causes the processor 232 to perform the following steps when being executed on the processor 232: a) detecting, by the detection unit 231, with the at least one electrode 20, 21, at least one of an intrinsic atrial signal and an intrinsic right ventricular signal, or stimulating, with the at least one electrode 20, 21, the atrium 2 of the heart 1 to be stimulated; b) triggering, by the processor 232 or the evaluation unit 234, a stimulation of the left ventricle 5 of the heart 1 to be stimulated upon i) detecting the intrinsic atrial signal, ii) stimulating the atrium 2, or iii) detecting the intrinsic right ventricular signal, wherein triggering upon i) detecting the intrinsic atrial signal or ii) stimulating the atrium (2) is carried out only with a predeterminable temporal delay, and triggering upon iii) detecting the intrinsic right ventricular signal is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding left ventricular signal, the first time period representing an allowable minimum ventricular interval; and c) stimulating, by the stimulation unit 235, the left ventricle.

Claims

Claims1. Implantable medical device for stimulating a human or animal heart, comprising a processor (232), a memory unit (233), a stimulation unit (235) configured to stimulate a human or animal heart (1), a detection unit (231) configured to detect an electric signal of the same heart (1), and at least one electrode (20, 21) forming part of the stimulation unit (235) and the detection unit (231), characterized in that the at least one electrode (20, 21) comprises a distal dipole (203) which is designed and arranged to be implanted within the septum (13) of the heart (1) to be stimulated, and in that the memory unit (233) comprises a computer-readable program that causes the processor (232) to perform the following steps when being executed on the processor (232): a) detecting, with the at least one electrode (20, 21), at least one of an intrinsic atrial signal and an intrinsic ventricular signal, or stimulating, with the at least one electrode (20, 21), the atrium (2) of the heart (1) to be stimulated; b) triggering a stimulation of the ventricle (5) of the heart (1) to be stimulated upon i) detecting the intrinsic atrial signal, ii) stimulating the atrium (2), or iii) detecting the intrinsic ventricular signal, wherein triggering upon i) detecting the intrinsic atrial signal or ii) stimulating the atrium (2) is carried out only with a predeterminable temporal delay, and triggering upon iii) detecting the intrinsic ventricular signal is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding ventricular signal.

2. Implantable medical device according to claim 1, characterized in that the detecting comprises detecting at least one of an intrinsic atrial signal and an intrinsic right ventricular signal and the triggering comprises triggering a stimulation of the left ventricle (5) upon i) detecting the intrinsic atrial signal, ii) stimulating the atrium (2), or iii) detecting the intrinsic right ventricular signal, wherein the triggering upon i) detecting the intrinsic atrial signal or ii) stimulating the atrium (2) is carried out only with a predeterminable temporal delay, and the triggering upon iii) detecting the intrinsic right ventricular signal is carried out without temporal delay but only if apredeterminable first time period has passed since a preceding left ventricular signal, the first time period representing an allowable minimum ventricular interval.

3. Implantable medical device according to any one of claims 1 or 2, characterized in that the computer-readable program causes the processor (232) to allow an activation and a deactivation of a functionality featuring the triggering upon detecting the intrinsic ventricular signal.

4. Implantable medical device according to claim 3, characterized in that the implantable medical device (22) comprises a communication unit (236) configured to receive instructions from an external device, wherein the instructions are instructions on the activation and the deactivation of the functionality featuring the triggering upon detecting the intrinsic ventricular signal.

5. Implantable medical device according to any one of claims 3 or 4, characterized in that the computer-readable program causes the processor (232) to allow a separate activation and a separate deactivation of the functionality featuring the triggering upon detecting the intrinsic ventricular signal for atrially controlled operational modes and for ventricularly controlled operational modes of the implantable medical device (22).

6. Implantable medical device according to any of the preceding claims, characterized in that the intrinsic ventricular signal is a signal originating from a ventricular extrasystole or a signal originating from a regular ventricular contraction.

7. Implantable medical device according to claim 6, characterized in that computer- readable program causes the processor (232) to allow a separate activation and a separate deactivation of i) a functionality featuring the triggering upon detecting the intrinsic ventricular signal, wherein the intrinsic ventricular signal is a signal originating from a ventricular extrasystole and of ii) a functionality featuring the triggering upon detecting the intrinsic ventricular signal, wherein the intrinsic ventricular signal is a signal originating from a regular ventricular contraction.

8. Implantable medical device according to any of the preceding claims, characterized in that the implantable medical device (22) comprises two electrodes (20, 21), wherein a second electrode (21) comprises an atrial dipole (213) being configured to detect the intrinsic atrial signal and / or wherein the atrial dipole is configured to be implanted within an atrial wall of the heart (1) to be stimulated.

9. Implantable medical device according to any of claims 1 to 7, characterized in that the implantable medical device (22) comprises only a single electrode (20), wherein the single electrode (20) comprises, besides the distal dipole (203), a proximal dipole (213) being configured to detect the intrinsic atrial signal and / or wherein the proximal dipole is configured to be floating supported within the atrium.

10. Implantable medical device according to claim 9, characterized in that the implantable medical device comprises (22) a header (230) having only a single electrode connector receiving socket.

11. Method for operating an implantable medical device (22) according to any of the preceding claims, the method comprising the following steps: a) detecting, with the at least one electrode (20, 21), at least one of an intrinsic atrial signal and an intrinsic ventricular signal; b) providing a stimulation trigger signal for a subsequent stimulation of the ventricle (5) of the heart (1) to be stimulated upon i) detecting the intrinsic atrial signal, or ii) detecting the intrinsic ventricular signal, wherein providing a stimulation trigger signal upon i) detecting the intrinsic atrial signal is carried out only with a predeterminable temporal delay, and providing a stimulation trigger signal upon ii) detecting the intrinsic ventricular signal is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding ventricular signal.

12. Method for providing a cardiac resynchronization therapy to a patient in need thereof, the method comprising the following steps:a) detecting, with an electrode (20) of an implantable medical device (22) for stimulating a human or animal heart (1), in particular of an implantable medical device (22) according to any of claims 1 to 10, an intrinsic atrial signal or an intrinsic ventricular signal, or stimulating, with an electrode (20) of an implantable medical device (22) for stimulating a human or animal heart (1), in particular of an implantable medical device (22) according to any of claims 1 to 11, an atrium (2) of the patient’s heart (1), wherein the electrode (20) comprises a distal dipole (203) and is implanted within the septum (13) of the patient’s heart (1); b) triggering a stimulation of the ventricle (5) of the patient’s heart (1) upon detecting the intrinsic atrial signal or upon stimulating the atrium (2), wherein the triggering is carried out only with a predeterminable temporal delay after detecting the intrinsic atrial signal or after stimulating the atrium (2), or triggering a stimulation of the ventricle (5) of the patient’s heart (1) upon detecting the intrinsic ventricular signal, wherein the triggering is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding ventricular signal.

13. Method according to claim 11 or 12, characterized in that an intrinsic right ventricular signal is detected and a trigger signal for a subsequent stimulation of a left ventricle is provided or a stimulation of a left ventricle is triggered, respectively, upon detecting the intrinsic right ventricular signal, wherein the providing the trigger signal or the triggering, respectively, is carried out without temporal delay but only if a predeterminable first time period has passed since a preceding left ventricular signal.

14. Method according to claim 11 or 12, characterized in that the intrinsic atrial signal is detected or the atrium (2) is stimulated and a trigger signal for a subsequent stimulation of a left ventricle is provided or a stimulation of a left ventricle is triggered, respectively, upon detecting the intrinsic atrial signal or upon stimulating the atrium (2), wherein the providing of the trigger signal or the triggering, respectively, is carried out only with a predeterminable temporal delay after detecting the intrinsic atrial signal or after stimulating the atrium (2).

15. Method according to any one of claims 11 to 14, characterized in that the intrinsic ventricular signal is a signal originating from a ventricular extrasystole or a signal originating from a regular ventricular contraction.

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