Patent ID: 8244353

Claim:
An implantable cardiac stimulator including: a. a cardioversion/defibrillation unit: (1) in communication with at least one electrode pair, and (2) being adapted to deliver cardioversion shocks through the electrode pair; b. an atrial sensing unit: (1) identifying an atrial contraction, and (2) outputting an atrial sensing signal when an atrial contraction is identified; c. a ventricular sensing unit: (1) identifying a ventricular contraction, and (2) outputting a ventricular sensing signal when a ventricular contraction is identified; d. a tachycardia detection unit: (1) receiving the atrial and ventricular sensing signals from the atrial sensing unit and ventricular sensing unit, (2) identifying a tachycardia therefrom, the identified tachycardia including one or more of: (a) a ventricular tachycardia (VT) or (b) a supraventricular tachycardia (SVT); wherein the tachycardia detection unit further identifies any atrial fibrillation (AFib) giving rise to a supraventricular tachycardia (SVT); e. a treatment control unit triggering an atrial cardioversion shock by the cardioversion/defibrillation unit when: (1) the rhythm of the ventricular contractions identified by the ventricular sensing unit is greater than a predefined frequency limit, and (2) the tachycardia detection unit identifies a supraventricular tachycardia (SVT) arising from an atrial fibrillation (AFib).