A medical device processor is configured to receive at least one cardiac electrical signal that is sensed during bilateral bundle branch pacing delivered from a bipolar electrode pair comprising an anode positioned along a first bundle branch and a cathode positioned along a second bundle branch opposite the first bundle branch, determine at least one feature from the first cardiac electrical signal, determine that the at least one feature meets first bundle branch capture criteria; and determine anodal bundle branch capture in response to the first bundle branch capture criteria being met.

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.

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.

In at least one example, a medical device is provided. The medical device includes at least one therapy electrode, at least one acoustic sensor, and at least one processor coupled with the at least one therapy electrode and the at least one acoustic sensor. The at least one processor is configured to deliver at least one pacing pulse via the at least one therapy electrode and to analyze processed acoustic data to determine whether the at least one pacing pulse resulted in capture.

In some examples, controlling delivery of cardiac resynchronization therapy (CRT) includes storing, in a memory of an implantable medical device system and in association with each of a plurality of heart rates, at least one respective value for an interval between an atrial event and a ventricular event. Processing circuitry of the implantable medical device system may determine a heart rate of a patient and select one of the stored values for the interval between the atrial event and the ventricular event associated with the determined heart rate. The processing circuitry may further determine whether to control therapy delivery circuitry of the implantable medical device system to deliver fusion pacing or biventricular pacing, based on the selected one of the stored values for the interval between the atrial event and the ventricular event.

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.

In some examples, a system can be used for delivering cardiac resynchronization therapy (CRT). The system may include a pacing device configured to be implanted within a patient. The pacing device can include a plurality of electrodes, signal generation circuitry configured to deliver ventricular pacing via the plurality of electrodes, and a sensor configured to produce a signal that indicates mechanical activity of the heart. Processing circuitry can be configured to identify one or more features of a cardiac contraction within the signal, and determine whether the contraction was a fusion beat based on the one or more features.

A stimulation device includes an energy source; an electronics unit; an actuator that is coupled with the electronics unit and/or the energy source. The electronics unit includes a controller. The energy source, the electronics unit and the actuator are arranged in a housing. A fixing unit which is coupled with the housing and affixes the stimulation device on a heart or in a heart. The actuator emits electromagnetic waves for the stimulation of genetically manipulated tissue, and the controller controls the stimulation of the tissue by way of the electromagnetic waves of the actuator.

Systems and methods for implanting a lead. The system includes an active guidewire having proximal and distal ends. The distal end includes a guidewire anchor that is configured to be attached to a target SOL. The active guidewire is configured to be utilized to electrically map the target SOI by at least one of delivering stimulation energy through the active guide wire to the target SOI or sensing an evoked response at the target SOI from the guidewire. The system also includes a lead having a lead body with proximal and distal ends and with a lumen extending between the proximal and distal ends. The distal end of the lead body is configured to receive the proximal end of the active guidewire. The lumen is configured to permit the lead body to be advanced over the active guidewire.

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.