Patent ID: 7574258

Claim:
A system for delivering therapy to a heart, comprising: a lead system, the lead system comprising electrodes and extending into the heart; pulse generator circuitry coupled to the lead system, the pulse generator circuitry configured to generate pulses to electrically stimulate the heart; a detector system, the detector system coupled to the lead system and configured to sense cardiac signals transmitted through the lead electrodes and to detect atrial arrhythmia; a control system coupled to the detector system and the pulse generator, the control system configured to, following detection of a tachyarrhythmic episode, control the generation of pace pulses during the tachyarrhythmic episode, form a morphological feature set from cardiac signals sensed following one or more of the pace pulses; detect entrainment of cardiac activity if features of a predetermined number of the cardiac signals sensed following the pace pulses are consistent with the morphological feature set, and trigger delivery of a cardioversion/defibrillation stimulation in response to detection of entrainment.