A medical device for stimulating the heart using biventricular stimulation. The device includes a sensor for detecting an endocardial acceleration parameter and a processing circuit configured to receive the endocardial acceleration parameter. The device further includes stimulation electronics coupled to the processing circuit. The processing circuit is configured to use the EA parameter to evaluate the biventricular stimulation. The evaluation includes comparing the value of the EA parameter in biventricular mode to the value of the EA parameter in left only mode or right only mode, and using the comparison and an assessment of the variability of the EA parameter as a function of the AVD in the left or right mode to distinguish between cases comprising: (a) normal operation, (b) a loss of RV or LV capture, (c) possible anodal stimulation. The processing circuit is further configured to conduct at least one update to operational parameters of the device based on the determined case.

An implantable medical device system receives a cardiac electrical signal produced by a patient's heart and comprising atrial P-waves and delivers a His bundle pacing pulse to the patient's heart via a His pacing electrode vector. The system determines a timing of a sensed atrial P-wave relative to the His bundle pacing pulse and determines a type of capture of the His bundle pacing pulse in response to the determined timing of the atrial P-wave.

For use by an implantable system including a first and second leadless pacemakers (LPs) implanted, respectively, in first and second cardiac chambers, a method comprises storing, within memory of the first LP, a paced activation morphology template corresponding to far-field signal components expected to be present in an EGM sensed by the first LP when a pacing pulse delivered to the second cardiac chamber by the second LP captures the second cardiac chamber. The method also includes the first LP comparing a morphology of a portion of an EGM sensed by the first LP to the paced activation morphology template to determine whether a match therebetween is detected, and determining whether capture of the second cardiac chamber occurred or failed to occur, based on whether the first LP detects a match between the morphology of the portion of the EGM and the paced activation morphology template.

A pacing system, which is particularly suitable for implantable leadless pacemakers, applies passively-balanced voltage-based pacing pulses, and periodically performs capture verification (evoked response detection) by following a pacing pulse with a current-based active balancing pulse, and then measuring any evoked response provoked by the pacing pulse. The active balancing pulse reduces residual charge on the electrodes used for pulsing, and thereby reduces polarization artifacts that could obscure measurement of the evoked response at the electrodes. The amplitude and pulse width of the active balancing current pulse are defined by measurements made in a few preceding pulses. The pacemaker preferably detects indicia of cardiac contractility, and performs capture verification only when contractility indicates that the patient is physically inactive and emotionally stable.

A biostimulator, such as a leadless pacemaker, having electrode(s) coated with low-polarization coating(s), is described. A low-polarization coating including titanium nitride can be disposed on an anode, and a low-polarization coating including a first layer of titanium nitride and a second layer of platinum black can be disposed on a cathode. The anode can be an attachment feature used to transmit torque to the biostimulator. The cathode can be a fixation element used to affix the biostimulator to a target tissue. The low-polarization coating(s) impart low-polarization to the electrode(s) to enable an atrial evoked response to be detected and used to effect automatic output regulation of the biostimulator. Other embodiments are also described and claimed.

An implantable medical device including a control unit, at least a right ventricular sensing unit and/or a right atrial sensing unit, wherein the right ventricular sensing unit is connected or can be connected to a right ventricular stimulation electrode lead having at least one electrode pole and a stimulation unit that is connected or can be connected to a multipolar left ventricular stimulation electrode lead having a plurality of electrode poles. The control unit is adapted to determine right atrioventricular conduction state and to cause selection of one of the plurality of electrode poles of the multipolar left ventricular stimulation electrode lead depending a respective determined right atrioventricular conduction state.

A medical device for stimulating the heart using biventricular stimulation. The device includes a sensor for detecting an endocardial acceleration parameter and a processing circuit configured to receive the endocardial acceleration parameter. The device further includes stimulation electronics coupled to the processing circuit. The processing circuit is configured to use the EA parameter to evaluate the biventricular stimulation. The evaluation includes comparing the value of the EA parameter in biventricular mode to the value of the EA parameter in left only mode or right only mode, and using the comparison and an assessment of the variability of the EA parameter as a function of the AVD in the left or right mode to distinguish between cases comprising: (a) normal operation, (b) a loss of RV or LV capture, (c) possible anodal stimulation. The processing circuit is further configured to conduct at least one update to operational parameters of the device based on the determined case.

Ventricle-from-atrium (VfA) cardiac therapy may utilize a tissue-piercing electrode implanted in the left ventricular myocardium of the patient's heart from the right atrium through the right atrial endocardium and central fibrous body. The exemplary devices and methods may determine whether the tissue-piercing electrode is achieving effective left ventricular capture. Additionally, one or more pacing parameters, or paced settings, may be adjusted in view of the effective left ventricular capture determination.

Ventricle-from-atrium (VfA) cardiac therapy may utilize a tissue-piercing electrode implanted in the left ventricular myocardium of the patient's heart from the right atrium through the right atrial endocardium and central fibrous body. The exemplary devices and methods may determine whether the tissue-piercing electrode is achieving effective left ventricular capture. Additionally, one or more pacing parameters, or paced settings, may be adjusted in view of the effective left ventricular capture determination.

A medical device is configured to sense a cardiac electrical signal and determine from the cardiac electrical signal at least one of a maximum peak amplitude of a positive slope of the cardiac electrical signal and a maximum peak time interval from a pacing pulse to the maximum peak amplitude. The device is configured to determine a capture type of the pacing pulse based on at least one or both of the maximum peak amplitude and the maximum peak time interval.