An implantable device and associated method for delivering multi-site pacing therapy is disclosed. The device comprises a set of electrodes including a first ventricular electrode and a second ventricular electrode, spatially separated from one another and all coupled to an implantable pulse generator. The device comprises a processor configured for selecting a first cathode and a first anode from the set of electrodes to form a first pacing vector at a first pacing site along a heart chamber and selecting a second cathode and a second anode from the set of electrodes to form a second pacing vector at a second pacing site along the same heart chamber. The pulse generator is configured to deliver first pacing pulses to the first pacing vector and delivering second pacing pulses to the second pacing vector. The pulse generator generates a recharging current for recharging a first coupling capacitor over a first recharge time period in response to the first pacing pulses. The pulse generator for generating a recharging current for recharging a second coupling capacitor over a second recharge time period in response to the second pacing pulses. An order of recharging the first and second coupling capacitors is dependent upon one of ventricular pacing mode, left ventricle to right ventricle delay (V-V) pace delay, multiple point LV delay and latest delivered pacing pulses to one of the first and second pacing vectors.

Methods and systems are provided for managing residual charge for multi-point pacing therapy. The method and system provide an electrode configuration that includes an atrial (A) electrode, a right ventricular (RV) electrode and multiple left ventricular (LV) electrodes. The method and system deliver pacing pulses for an MPP therapy, during a first cardiac cycle, from a pulse generator to the electrode configurations. The pacing pulses are separated by pacing pulse (PP) intervals. The method and system dynamically adjust at least one of a timing or a duration of discharge pulses for the residual charge to form a discharge sequence. The method and system activate the discharge pulses based on the discharge sequence, during the first cardiac cycle, to the multiple LV electrodes to distribute the residual charge across the PP intervals.

Systems and methods for reducing ventricle filling volume are disclosed. In some embodiments, a stimulation circuit may be used to stimulate a patient's heart to reduce ventricle filling volume or even blood pressure. When the heart is stimulated at a consistent rate to reduce blood pressure, the cardiovascular system may over time adapt to the stimulation and revert back to the higher blood pressure. In some embodiments, the stimulation pattern may be configured to be inconsistent such that the adaptation response of the heart is reduced or even prevented. In some embodiments, a stimulation circuit may be used to stimulate a patient's heart to cause at least a portion of an atrial contraction to occur while the atrioventricular valve is closed. Such an atrial contraction may deposit less blood into the corresponding ventricle than when the atrioventricular valve is opened throughout an atrial contraction.

An apparatus comprises a stimulus circuit, a cardiac signal sensing circuit, and a control circuit. The cardiac signal sensing circuit senses a cardiac activity signal using a sensing channel. The stimulus circuit provides electrical pulse energy to a first pacing channel that includes a first left ventricular (LV) electrode and a second pacing channel that includes a second LV electrode. The control circuit initiates delivery of electrical pulse energy using the first and second pacing channels according to a first multi-site LV pacing mode; determines a cardiac event associated with a change in cardiac conduction path using a sensed cardiac activity signal; and changes to a second LV pacing mode in response to determining the cardiac event. The second LV pacing mode is different from the first multi-site LV pacing mode in one or more of a pacing site location and inter-electrode stimulus timing.

Methods and devices for reducing ventricle filling volume are disclosed. In some embodiments, an electrical stimulator may be used to stimulate a patient's heart to reduce ventricle filling volume or even blood pressure. When the heart is stimulated in a consistent way to reduce blood pressure, the cardiovascular system may over time adapt to the stimulation and revert back to the higher blood pressure. In some embodiments, the stimulation pattern may be configured to be inconsistent such that the adaptation response of the heart is reduced or even prevented. In some embodiments, an electrical stimulator may be used to stimulate a patient's heart to cause at least a portion of an atrial contraction to occur while the atrioventricular valve is closed. Such an atrial contraction may deposit less blood into the corresponding ventricle than when the atrioventricular valve is opened throughout an atrial contraction.

Methods and devices are is provided for controlling a pacing therapy utilizing left ventricular multi-point pacing (MPP). The method and device provide electrodes configured to be located proximate to an atrial (A) site, a right ventricular (RV) site and multiple left ventricular (LV) sites of the heart. The method and device utilizes one or more processors. The processors determine atrial-ventricular conduction delays (AVCD) between the A site and multiple corresponding LV sites and determines pacing latencies at the LV sites. The processors adjusts the AVCDs, based on the pacing latency at the corresponding LV sites, to form atrial-ventricular latency adjusted (ARPL) conduction delays for the corresponding LV sites, calculates interventricular pacing (VV) delays for combinations of the LV sites based on the corresponding ARPL conduction delays and manages pacing therapy, that utilizes left ventricular MPP, based on the VV delays for the corresponding LV sites.

Computer implemented methods, devices and systems for monitoring a trend in heart failure (HF) progression are provided. The method comprises sensing left ventricular (LV) activation events at multiple LV sensing sites along a multi-electrode LV lead. The activation events are generated in response to an intrinsic or paced ventricular event. The method implements program instructions on one or more processors for automatically determining a conduction pattern (CP) across the LV sensing sites based on the LV activation events, identifying morphologies (MP) for cardiac signals associated with the LV activation events and repeating the sensing, determining and identifying operations, at select intervals, to build a CP collection and an MP collection. The method calculates an HF trend based on the CP collection and MP collection and classifies a patient condition based on the HF trend to form an HF assessment.

Methods and devices are provided for, under control of one or more processors within an implantable medical device (IMD), delivering cardiac resynchronization therapy (CRT) at one or more pacing sites. The processors obtain cardiac signals, associated with a candidate beat, from multi-site left ventricular (MSLV) electrodes distributed along a left ventricle and analyze the cardiac signals to collect at least one of a MSLV conduction pattern or a MSLV morphology. The processors compare at least one of the MSLV conduction pattern or MSLV morphology to one or more associated templates. The processors then label the candidate beat as a pseudo-fusion beat based on the comparing and adjust the CRT based on the labeling.

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 apparatus comprises a stimulus circuit, a recharge circuit, a switch circuit, and a control circuit. The stimulus circuit provides electrical cardiac pacing stimulation to multiple combinations of a plurality of electrodes, and the electrical stimulation is selectively applied at the first electrode of the electrode combinations. The recharge circuit includes a recharge capacitor electrically coupled to the second electrode of the electrode combinations, and the switch circuit selectively enables electrode combinations for electrical coupling to the stimulus circuit and the recharge circuit. The control circuit includes a pacing activation sub-circuit that selectively initiates delivery of the electrical stimulation using multiple electrode combinations, and enables simultaneous delivery of pacing recharge energy from the recharge capacitor to the second electrode of multiple electrode combinations.