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.

A method and apparatus for treatment of hypertension and heart failure by increasing vagal tone and secretion of endogenous atrial hormones by excitory pacing of the heart atria. Atrial pacing is done during the ventricular refractory period resulting in atrial contraction against closed AV valves, and atrial contraction rate that is higher than the ventricular contraction rate. Pacing results in the increased atrial wall stress. An implantable device is used to monitor ECG and pace the atria in a nonphysiologic manner.

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.

Systems and methods are provided for detecting arrhythmias in cardiac activity is provided. The systems and methods include measuring conduction delays between an atria (A) and multiple left ventricular (LV) electrodes to obtain multiple intrinsic A/LV intervals, measuring conduction delays between a right ventricular (RV) and the multiple LV electrodes to obtain multiple intrinsic VV intervals. The systems and methods include calculating a first atrial ventricular (AV) delay based on at least one of the intrinsic A/LV intervals, and calculating a second AV delay based on at least one of the intrinsic VV intervals. The systems and methods include selecting a biventricular (BiV) pacing mode or an LV only pacing mode based on a relation between the first and second AV delays, and delivering a pacing therapy based on the selecting operation.

Various embodiments include methods of cardiac resynchronization therapy (CRT). Various embodiments may include: generating, using a processing unit, a cardiac activation map including a three-dimensional (3D) heart model of the heart that shows coronary vessels of a patient and shows the propagation of electrical signals through the 3D heart model; determining the location of a left bundle branch block (LBBB) based on the cardiac activation map; implanting a first pacing device and a second pacing device into the patient; stimulating the His Bundle of the heart using the first pacing device; and stimulating the left ventricle (LV) of the heart at a position downstream of the LBBB with respect to a direction of electrical conduction through the LV using the second pacing device after stimulating the His bundle.

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.

A cardiac pacemaker is disclosed for pacing cardiac tissue to improve synchrony between the atria and ventricles and/or between the left and right ventricles. A pulse generator is configured to deliver a pacing pulse to a patient's ventricle at an atrioventricular (AV) delay following a preceding atrial event. A sensing circuitry configured to sense a signal from the patient's ventricle following delivery of a said pacing pulse. A processing circuitry coupled to the pulse generator and the sensing circuitry and configured to control the pulse generator, the processing circuitry further configured to: (1) acquire from the sensed signal a set of features; (2) determine whether the ventricular pacing pulse effectively captures the patient's ventricle using the set of features; (3) determine whether one or more tissue latency conditions are present. The one or more pacing pulse parameters are adjusted, in response to determining that tissue latency is present.

The disclosure relates to a device including a plurality of electrodes for stimulation of both ventricles with application of an atrioventricular delay and of an interventricular delay, a processor configured to multidimensionally measure an interventricular conduction delay, and monitor the evolution of a patient's condition. For the multidimensional measurement of the interventricular conduction delay, the device produces stimulation of one of the ventricles and collects, in the other ventricle, two endocardial electrogram signals on separate respective channels, giving two respective temporal components. Both temporal components are combined in one single parametric 2D characteristic representative of the cardiac cycle, and a comparison is made with reference descriptors for deriving an index representative of the evolution of the patient's condition.