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.

An implantable medical device and medical device system for delivering a bi-ventricular pacing therapy that includes a plurality of electrodes to sense a cardiac signal, an emitting device to emit a trigger signal to control delivery of the bi-ventricular pacing, and a processor configured to compare the sensed cardiac signal associated with the delivered bi-ventricular pacing to at least one of an intrinsic beat template and an RV template associated with a morphology of RV-only pacing therapy, determine whether an offset interval associated with the bi-ventricular pacing therapy is set to a maximum offset interval level in response to the comparing, adjust the offset interval in response to the offset interval not being set to the maximum offset interval level, and generate the trigger signal to be emitted by the emitting device to subsequently deliver the bi-ventricular pacing therapy having the adjusted offset interval.

A system and method control a pacing parameter in a closed-loop manner by determining a value of an EGM-based index corresponding an optimal electrical activation condition of a patient's heart and adjusting a pacing therapy to maintain the EGM-based index value. The closed loop control method performed by the system may establish a relationship between an EGM-based index and multiple settings of a pacing control parameter. Values of the EGM-based index are stored with corresponding setting shifts relative to a previously established optimal setting. A processor of an implantable medical device monitors the EGM-based index during cardiac pacing. Responsive to detecting an EGM-based index value corresponding to a non-optimal setting of the control parameter, the processor determines an adjustment of the control parameter from the stored index values and corresponding setting shifts.

Provided herewith are methods and apparatus for optimizing an atrioventricular (AV) pacing delay interval. One manner described involves dynamically programming an AV interval in cardiac resynchronization therapy (CRT) device having a rate-adaptive AV (RAAV) feature in such a way that not less than a minimum AV interval is maintained. That is, the AV interval is not allowed to be reduced so much that the P-wave is truncated by the QRS complex. In this form of the invention, the AV interval is reduced by one millisecond per one bpm increase in heart rate (and vice versa for reducing heart rate) but maintained at a value calculated from the end of the P-wave (PWend) and the beginning of the QRS complex (QRSbeg) or delivery of a ventricular pacing stimulus or to the end of the end of the QRS complex (QRSend).

A medical device system and associated method predict a patient response to a cardiac therapy. The system includes for delivering cardiac pacing pulses to a patient's heart coupled to a cardiac sensing module and a cardiac pacing module for generating cardiac pacing pulses and controlling delivery of the pacing pulses at multiple pace parameter settings. An acoustical sensor obtains heart sound signals. A processor is enabled to receive the heart sound signals, derive a plurality of heart sound signal parameters from the heart sound signals, and determine a trend of each of the plurality of heart sound signal parameters with respect to the plurality of pace parameter settings. An external display is configured to present the trend of at least one heart sound parameter with respect to the plurality of pace parameter settings.

Devices and methods for improving device therapy such as cardiac resynchronization therapy by determining a value for a device parameter are described. An ambulatory medical device (AMD) can include a sensor circuit to sense a physiological signal and generate two or more signal metrics, and detect an event of worsening cardiac condition using the two or more signal metrics. In response to the detection of worsening cardiac condition, the AMD can determine, for a stimulator, a value of at least one stimulation parameter based on temporal responses of two or more signal metrics. The temporal responses include near-term and long-term responses to the stimulation. The AMD can program the stimulator with the determined parameter value, and generate stimulation according to the determined parameter value to stimulate target tissue.

An implantable medical device is provided that comprises a pulse generator circuit that times delivery of ventricular pacing pulses based on a base intracardiac interval (ICI). A processor is provided that has memory storing program instructions and storing atrial and ventricular events over multiple cardiac cycles and that is responsive to execution of the program instructions. The processor adjusts the base ICI by an ICI adjustment, during one or more of the multiple cardiac cycles, to promote intrinsic heart activity. The processor further counts a number of the cardiac cycles in which the ICI adjustments occurred in conjunction with arrhythmias to identify an excessive adjustment count and modifies the ICI adjustment to utilize a new ICI adjustment based on the excessive adjustment count.

Systems and methods for switching modes in a multi-device medical system. In one example, a first leadless cardiac pacemaker (LCP) may be implantable at a ventricular site, and a second leadless cardiac pacemaker (LCP) may be implantable at an atrial site and configured to sensing atrial contractions. The first LCP and the second LCP may be configured to be communicatively coupled such that the first LCP and the second LCP can deliver pacing therapy to the ventricular site in a tracking mode. The first LCP and/or the second LCP may additionally be configured to deliver pacing therapy to the ventricular site in a non-tracking mode if an interval between atrial contractions sensed by the second LCP becomes shorter than a threshold duration.

A method, apparatus, or system to identify optimal parameters for programming a cardiac stimulator by a matrix-based decision algorithm using sensor data representing cardiovascular function. The parameters include pacing intervals optimized concurrently to produce the maximum resulting cardiac function.

The disclosure relates to systems and methods for cardiac rhythm management. In some cases, a system may include a pulse generator for generating pacing pulses for stimulating a heart of a patient; a memory; and a sensor configured to sense a response to a unwanted stimulation and to produce a corresponding sensor signal. A processing circuit may receive the sensor signal for a time after one or more pacing pulses, and may derive a time-frequency representation of the sensor signal based on the received sensor signal. The processing circuit may use the time-frequency representation of the sensor signal to help identify unwanted stimulation. Once unwanted stimulation is detected, the processing circuit may change the pacing pulses to help reduce or eliminate the unwanted stimulation.