Patent ID: 7522956

Claim:
An implantable cardioverter-defibrillator, comprising: an atrial catheter including at least one atrial sensing electrode; a ventricular catheter including at least one ventricular sensing electrode and at least one ventricular defibrillation electrode; sensing circuitry, coupled to the atrial catheter and the ventricular catheter, the sensing circuitry adapted to sense atrial events and ventricular events from the electrodes; therapy delivery circuitry, coupled to the ventricular catheter, the therapy delivery circuitry adapted to apply or inhibit a ventricular tachycardia therapy; and control circuitry, coupled to the sensing circuitry and therapy circuitry, the control circuitry adapted to: detect at least one of a ventricular tachycardia and a ventricular fibrillation by analyzing the sensed ventricular events; start a first time interval when the at least one of the ventricular tachycardia and the ventricular fibrillation is detected; analyze the sensed atrial and ventricular events during the first time interval for assessing an origin of the detected at least one of the ventricular tachycardia and the ventricular fibrillation; determine whether to delay or inhibit the ventricular tachycardia therapy based on the origin of the detected at least one of the ventricular tachycardia and the ventricular fibrillation; determine whether the detected at least one of the ventricular tachycardia and the ventricular fibrillation is sustained during the first time interval; and reset the first time interval if the at least one of the ventricular tachycardia and the ventricular fibrillation does not sustain during the first time interval.