A biostimulator, such as a leadless pacemaker, has electrode(s) coated with low-polarization coating(s). 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.

A method of selecting a combination of electrodes for use in neurostimulation includes testing combinations of electrodes in an electrode array to identify an atrial capture. The atrial capture is indicated by at least one effect on an atrium. The method includes excluding electrodes with the atrial capture to result in remaining electrodes of the electrode array, testing combinations of the remaining electrodes of the electrode array for effect on cardiac contractility and/or relaxation, and selecting a combination of electrodes from the remaining electrodes. The selected combination has both a desired effect on cardiac contractility and/or relaxation and does not have an undesired side effect.

Systems and methods for monitoring and treating patients with heart failure (HF) are discussed. The system may sense cardiac signals, and receives information about patient physiological or functional conditions. A stimulation parameter table that includes recommended values of atrioventricular delay (AVD) or other timing parameters maybe created at a multitude of patient physiological or functional conditions. The system may periodically reassess patient physiological or functional conditions. A therapy programmer circuit may dynamically switch between left ventricular-only pacing and biventricular pacing, or switch between single site pacing and multisite pacing based on the patient condition. The therapy programmer circuit may adjust AVD and other timing parameters using the cardiac signal input and the stored stimulation parameter table. A HF therapy may be delivered according to the determined stimulation site, stimulation mode, and the stimulation timing.

Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.

Systems and methods for pacing cardiac conductive tissue are described. In an embodiment, a medical system includes an electrostimulation circuit to generate His-bundle pacing (HBP) pulses. A sensing circuit senses an atrial activation. A control circuit detects a retrograde atrial conduction timing, such as a His-to-atrial interval between the HBP pulse and the sensed atrial activation in response to the HBP pulse, and verifies capture status using the determined retrograded atrial conduction timing. Based on the capture status, the control circuit determines a HBP threshold, and the electrostimulation circuit delivers HBP pulses in accordance with the determined HBP threshold.

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.

Certain embodiments of the present technology described herein relate to detecting atrial oversensing in a His intracardiac electrogram (His IEGM), characterizing atrial oversensing, determining when atrial oversensing is likely to occur, and or reducing the chance of atrial oversensing occurring. Some such embodiments characterize and/or avoid atrial oversensing within a His IEGM. Other embodiments of the present technology described herein relate to determining whether atrial capture occurs in response to His bundle pacing (HBP). Still other embodiments of the present technology described herein relate to determining whether AV node capture occurs in response to HBP.

Certain embodiments of the present technology described herein relate to detecting atrial oversensing in a His intracardiac electrogram (His IEGM), characterizing atrial oversensing, determining when atrial oversensing is likely to occur, and or reducing the chance of atrial oversensing occurring. Some such embodiments characterize and/or avoid atrial oversensing within a His IEGM. Other embodiments of the present technology described herein relate to determining whether atrial capture occurs in response to His bundle pacing (HBP). Still other embodiments of the present technology described herein relate to determining whether AV node capture occurs in response to HBP.

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 signal, determine a monitoring metric representative of activity of at least one heart chamber from the sensed cardiac signal, and determine that the monitoring metric meets expected rhythm criteria. The medical device may enable a monitoring feature of the medical device that is based on processing and analysis of the cardiac signal in response to the monitoring metric meeting the expected rhythm criteria.