Abstract: An implantable medical device may deliver pacing, cardioversion, and/or defibrillation stimulation to a heart of a patient via extravascular electrodes and delivers electrical stimulation to a nonmyocardial tissue site to modulate the autonomic nervous system of the patient. The implantable medical device may include a cardiac therapy module that generates and delivers at least one of pacing, cardioversion, or defibrillation therapy to a patient via an extravascular electrode, and a neurostimulation therapy module that generates and delivers a neurostimulation signal to the patient via a neurostimulation electrode. The cardiac therapy module and neurostimulation therapy module may be disposed in a common housing of the medical device. In some examples, at least one common lead may electrically couple the neurostimulation electrode and the extravascular electrode to the neurostimulation and cardiac therapy modules, respectively.

Abstract: An implantable system and method are provided for detecting myocardial electrical recovery time and for controlling the delivery of cardiac stimulation pulses relative to the detected recovery time. One or more fiducial points on a T-wave signal sensed from one or more intracardiac EGM or subcutaneous ECG signals are detected for estimating myocardial recovery time. Extra systolic stimulation pulses are delivered at an extra systolic interval based on a detected recovery time to effectively produce post-extra systolic potentiation while preventing delivery of extra systolic stimuli during the vulnerable period.