IMPLANTABLE MEDICAL DEVICE FOR STIMULATING A HUMAN OR ANIMAL HEART EMPLOYING AN EVALUATION OF SIGNALS BETWEEN A HIS ELECTRODE AND A FURTHER ELECTRODE

Abstract

An implantable medical device stimulates a human or animal heart. The medical device contains a processor, a memory unit, a His electrode having a first electrode pole configured to detect an electrical signal at a His bundle of a heart, and a further electrode having a further electrode pole configured to detect an electrical signal at a cardiac region of the same heart different from the His bundle. During operation of the device, performing the steps of: measuring electric signals at a His bundle of a heart with the first electrode pole; measuring electric signals at a cardiac region of the same heart different from the His bundle with the further electrode pole; and evaluating intracardiac electrogram signals and/or impedance signals measured between the first electrode pole and the further electrode pole, with the provision that this evaluating does not only contain a determination of an atrial-His bundle transition time.

Claims

1. An implantable medical device for stimulating a human or animal heart, the implantable medical device comprising: a processor; a His electrode having a first electrode pole configured to detect an electrical signal at a His bundle of the human or animal heart; at least one further electrode having at least one further electrode pole configured to detect an electrical signal at a cardiac region of the human or animal heart being different from the His bundle; a memory unit having computer-readable instructions causing said processor to perform the following steps when executed on said processor: measure electric signals at the His bundle of the human or animal heart with said first electrode pole; measure electric signals at the cardiac region of the human or animal heart being different from the His bundle with said at least one further electrode pole; and evaluate intracardiac electrogram signals and/or impedance signals measured between said first electrode pole and said at least one further electrode pole, with a provision that the evaluating step does not only comprise a determination of an atrial-His bundle transition time.

2. The implantable medical device according to claim 1, wherein the cardiac region is different from the His bundle is a right atrium, a right ventricle or a left ventricle.

3. The implantable medical device according to claim 1, wherein the computer-readable instructions cause said processor to determine a relation between a signal detected by said first electrode pole and a signal detected by said at least one further electrode.

4. The implantable medical device according to claim 3, wherein the relation is or contains a time relation between the two signals.

5. The implantable medical device according to claim 3, wherein the relation is or comprises an amplitude relation between the two signals.

6. The implantable medical device according to claim 3, wherein the computer-readable instructions cause said processor to determine a condition of the human or animal heart on a basis of the intracardiac electrogram signals and/or the impedance signals.

7. The implantable medical device according to claim 1, wherein the computer-readable instructions cause said processor to determine, based on a performed evaluation, at least one parameter representative for a hemodynamics and/or a contractility of the human or animal heart.

8. The implantable medical device according to claim 1, wherein the computer-readable instructions cause said processor to adjust, based on a performed evaluation, an algorithm for controlling the implantable medical device.

9. The implantable medical device according to claim 8, wherein the algorithm is chosen from the group consisting of a capture classification algorithm, an automatic threshold test, a beat-to-beat capture control algorithm, and a closed loop stimulation algorithm.

10. The implantable medical device according to claim 1, wherein said at least one further electrode is a quadrupolar electrode having four electric poles.

11. The implantable medical device according to claim 10, wherein the computer-readable instructions cause said processor to determine a change of an impedance between each of said four electric poles and said first electric pole during a cardiac cycle over a first period of time.

12. A method for determining a condition of a human or animal heart using an implantable medical device for stimulating the human or animal heart, the implantable medical device having a processor, a memory unit, a His electrode having a first electrode pole configured to detect an electrical signal at a His bundle of the human or animal heart, at least one further electrode having at least one further electrode pole configured to detect an electrical signal at a cardiac region of the human or animal heart different from the His bundle, the method comprises the following steps of: measuring electric signals at the His bundle of the human or animal heart with the first electrode pole; measuring electric signals at the cardiac region of the human or animal heart different from the His bundle with the at least one further electrode pole; evaluating intracardiac electrogram signals and/or impedance signals measured between the first electrode pole and the at least one further electrode pole, with a provision that the evaluating does not only comprise a determination of an atrial-His bundle transition time; and determining a condition of the animal or human heart on a basis of the evaluating step.

13. A non-transitory computer readable medium containing computer-readable code that causes a processor to perform the following steps when executed on the processor: measure electric signals at a His bundle of a human or animal heart with a His electrode having a first electrode pole; measure electric signals at a cardiac region of the human or animal heart different from the His bundle with at least one further electrode having at least one further electrode pole; and evaluate intracardiac electrogram signals and/or impedance signals measured between the first electrode pole and the at least one further electrode pole with a provision that the evaluating does not only comprise a determination of an atrial-His bundle transition time.

14. A method of treatment of a human or animal patient by means of an implantable medical device for stimulating the human or animal heart, wherein the implantable medical device containing a processor, a memory unit, a His electrode having a first electrode pole configured to detect an electrical signal at a His bundle of the human or animal heart, and at least one further electrode having at least one further electrode pole configured to detect an electrical signal at a cardiac region of the human or animal heart different from the His bundle, the method comprises the following steps of: measuring electric signals at the His bundle of the human or animal heart with the first electrode pole; measuring electric signals at the cardiac region of the human or animal heart different from the His bundle with the at least one further electrode pole; evaluating intracardiac electrogram signals and/or impedance signals measured between the first electrode pole and the at least one further electrode pole, with a provision that the evaluating does not only comprise a determination of an atrial-His bundle transition time; adjusting an algorithm for controlling the implantable medical device based on the evaluating step; and stimulating the cardiac region of the human or animal heart with at least one of the His electrode, the at least one further electrode or a simulation unit configured to stimulate the cardiac region, wherein the stimulating is performed by applying an adjusted algorithm.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0054] FIG. 1 is an illustration which schematically shows a first embodiment of an implantable medical device making use of data obtained by a His electrode and a right ventricular electrode along with schematic intracardiac electrograms; and

[0055] FIG. 2 is an illustration showing a second embodiment of an implantable medical device making use of data obtained by a His electrode and a left ventricular electrode.

DETAILED DESCRIPTION OF THE INVENTION

[0056] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown an implantable pulse generator 1 as example for a device for stimulating the human heart. The implantable pulse generator 1 comprises a His electrode 2 and a right ventricular electrode 3. The His electrode 2 is implanted such as to contact a His bundle 4 of a human heart 5, wherein the right ventricular electrode 3 is implanted such to contact the myocardium within a right ventricle 6 of the same heart 5.

[0057] During operation of the implantable pulse generator 1, and intracardiac electrogram (IEGM) between the His electrode 2 and the right ventricular electrode 3 is measured. On the right-hand side of FIG. 1, exemplary IEGMs 7 are depicted. Upon a stimulation pulse 8 with the His electrode 2, different types of IEGMs 7 can be detected. This depends on the exact positioning of the His electrode 2. In case of a selective capture of the His bundle 4, a elective capture IEGM 71 can be recorded. In case of a non-selective capture of the His bundle 4, a non-selective capture IEGM 72 can be recorded. In case that the His bundle is not captured at all, a no-capture IEGM 73 can be detected.

[0058] Thus, the different IEGMs 7 recorded between the His electrode 2 and the right ventricular electrode 3, or, to be more precise between a His electrode pole 20 serving as first electrode pole and a right ventricular electrode pole 30 serving as further electrode pole serve in assisting capture classification of the His bundle electrode 2. The information obtained by the IEGMs 7 recorded between the His electrode pole 20 and the right ventricular electrode pole 30 represents more exact and more reliable data than data obtained by relying only on a single electrode.

[0059] FIG. 2 shows another embodiment of an implantable pulse generator 1, wherein similar elements are denoted with the same numeral references as in FIG. 1. The implantable pulse generator 1 of FIG. 2 also comprises a His electrode 2 and right ventricular electrode 3, but additionally also comprises a left ventricular electrode 9. As in case of the embodiment depicted in FIG. 1, the His electrode 2 comprises a His electrode pole 20 being in contact with a His bundle 4 of the human heart 5. Likewise, the right ventricular electrode 3 comprises a right ventricular electrode pole 30 contacting the myocardium within the right ventricle 6 of the same heart 5. The left ventricular electrode 9 comprises four electrode poles 91, 92, 93 and 94 that are in contact with myocardium at the left ventricle 10 of the same heart 5.

[0060] It is possible to measure a first impedance Z1 between the first left ventricular electrode pole 91 and the His electrode pole 20, a second impedance Z2 between the second left ventricular electrode pole 92 and the His electrode pole 20, a third impedance Z3 between a third left ventricular electrode pole 93 and the His electrode pole 20, as well as a fourth impedance Z4 between the fourth left ventricular electrode pole 94 and the His electrode pole 20.

[0061] In doing so, four different impedances Z1, Z2, Z3, and Z4 are obtained that can be used to determine a length L between each of the left ventricular electrode poles 91, 92, 93, and 94 as well as the His electrode pole 20.

[0062] By evaluating a change of the four impedances Z1, Z2, Z3, and Z4 over time, detailed information with respect to the contractility of the heart 5 are obtained. Thus, an online measurement of the contractility of the human heart 5 is possible. Consequently, it is possible to online determine any changes of the condition of the human heart with respect to its contractility that can be indicative for a pathologic change of the cardiac power of the heart 5. This, in turn, may require an adjustment of pacing algorithms applied by the implantable pulse generator 1 when stimulating the heart 5. These algorithms are then adjusted on the basis of the determined change of the contractility of the heart 5.

[0063] It will be apparent to those skilled in the art that numerous modifications and variations of the described examples and embodiments are possible in light of the above teaching. The disclosed examples and embodiments are presented for purposes of illustration only. Other alternate embodiments may include some or all of the features disclosed herein. Therefore, it is the intent to cover all such modifications and alternate embodiments as may come within the true scope of this invention.