An implantable medical device system delivers a pacing pulse to a patient's heart and starts a first pacing interval corresponding to a pacing rate in response to the delivered pacing pulse. The system charges a holding capacitor to a pacing voltage amplitude during the first pacing interval. The system detects an increased intrinsic heart rate that is at least a threshold rate faster than the current pacing rate from a cardiac electrical signal received by a sensing circuit of the implantable medical device. The system starts a second pacing interval in response to an intrinsic cardiac event sensed from the cardiac electrical signal and withholds charging of the holding capacitor for at least a portion of the second pacing interval in response to detecting the increased intrinsic heart rate.

Methods and systems for detecting stability of the arrhythmia or fibrillation, determining whether defibrillation or pacing is needed to disrupt the fibrillation, and, if so, optimizing the timing of low energy therapies to improve efficacy of low energy therapy for defibrillation. By transforming electrogram signals into a discrete series of electrogram conformations, recurrence variables of the electrogram signal can be determined that are highly indicative of sources of the arrhythmia, that predict the likelihood of spontaneous termination of the arrhythmia, and that detect the optimal timing of low energy treatment to terminate the arrhythmia.

The present technology is generally directed to implantable medical device systems for stimulating tissue, such as heart tissue. In some embodiments, an implantable medical device system includes a controller-transmitter and a receiver-stimulator in operable communication with one another. The receiver-stimulator can be implanted at the heart of a patient. The controller-transmitter can be configured to transmit an acoustic signal to the receiver-stimulator, which receives the acoustic signal and converts the acoustic signal to electrical energy for delivery to the heart via one or more stimulation electrodes. The receiver-stimulator can further be configured to transmit a radiofrequency signal to the controller-transmitter including information about sensed physiological parameters of the patient, status information, and the like.

The present invention provides both methods and devices for termination of arrhythmias, such as ventricular or atrial tachyarrhythmias. The device and method involves application of alternating current (AC) for clinically significant durations at selected therapeutic frequencies through the cardiac tissue to a subject experiencing arrhythmia. Methods are also provided to minimize or eliminate pain during defibrillation.

Techniques are disclosed for a multi-tier system for delivering therapy to a patient. In one example, a first device senses parametric data for a patient and determines, based on a first analysis of the parametric data, that the patient is experiencing a treatable event. In response, the first device establishes wireless communication with a second device and transmits the parametric data to the second device. The second device verifies, based on a second analysis of the parametric data, whether the patient is experiencing the treatable event. The second device selects, based on the second analysis of the parametric data, an instruction for responding to the treatable event and transmits the instruction for responding to the treatable event to the first device. In some examples, in response to receiving the instruction, the first device aborts delivery of therapy for the treatable event or proceeds with delivering therapy for the treatable event.

Systems, methods and devices for delivering stimulating energy with a lead having a directional electrode are disclosed. The lead includes a directional electrode having an electrically active portion configured to emanate stimulating energy from an exposed portion of the directional electrode. The lead also has an electrically insulating portion around at least part of the circumference of the lead. The electrically insulating portion is configured to insulate surrounding muscle and/or tissue from the stimulating energy when the lead is implanted in the patient.

A device and method are described for transmitting tissue conductance communication (TCC) signals. A device may be is configured to establish a transmission window by transmitting a TCC test signal at multiple time points over a transmission test period to a receiving device and detect at least one response to the transmitted TCC test signals performed by the receiving device. The IMD is configured to establish the transmission window based on the at least one detected response so that the transmission window is correlated to a time of relative increased transimpedance between a transmitting electrode vector and receiving electrode vector during the transmission test period.

An implantable neurostimulator-implemented method for managing tachyarrhythmias through vagus nerve stimulation is provided. An implantable neurostimulator, including a pulse generator, is configured to deliver electrical therapeutic stimulation in a manner that results in creation and propagation (in both afferent and efferent directions) of action potentials within neuronal fibers of a patient's cervical vagus nerve. Operating modes of the pulse generator are stored. A maintenance dose of the electrical therapeutic stimulation is delivered to the vagus nerve via the pulse generator to restore cardiac autonomic balance through continuously-cycling, intermittent and periodic electrical pulses. A restorative dose of the electrical therapeutic stimulation is delivered to prevent initiation of or disrupt tachyarrhythmia through periodic electrical pulses delivered at higher intensity than the maintenance dose. The patient's normative physiology is monitored via a physiological sensor, and upon sensing a condition indicative of tachyarrhythmia, is switched to delivering the restorative dose to the vagus nerve.

A method and apparatus for treatment of hypertension and heart failure by increasing secretion of endogenous atrial hormones by pacing of the heart. Pacing is done during the ventricular refractory period resulting in premature atrial contraction that does not result in ventricular contraction. Pacing results in the atrial wall stress, peripheral vasodilation, ANP secretion. Concomitant reduction of the heart rate is monitored and controlled as needed with backup pacing.

A method and apparatus for treatment of hypertension and heart failure by increasing secretion of endogenous atrial hormones by pacing of the heart. Pacing is done during the ventricular refractory period resulting in premature atrial contraction that does not result in ventricular contraction. Pacing results in the atrial wall stress, peripheral vasodilation, ANP secretion. Concomitant reduction of the heart rate is monitored and controlled as needed with backup pacing.