Patent ID: 7353062

Claim:
A method for operating a cardiac rhythm management device, composing: measuring a ventricular rate from sensed ventricular electrical activity; detecting a tachyarrhythmia that may be either a supraventricular tachycardia (SVT) or a ventricular tachycardia (VT) if the measured ventricular rate is within a specified range; generating a first electrogram signal from a cardiac sensing channel; discriminating between SVT and VT with a test for SVT/VT discrimination that includes a morphology criterion based on an analysis of the first electrogram signal; delivering either a cardioversion/defibrillation shock or anti-tachycardia pacing to treat the tachyarrhythmia; and, if a cardioversion/defibrillation shock is delivered: discontinuing use of the morphology criterion in the test for SVT/VT discrimination after delivery of the cardioversion/defibrillation shock for at least one ventricular beat; judging whether or not one or more ventricular beats that occur after delivery of the cardioversion/defibrillation shock are normally conducted; and, resuming use of the morphology criterion in the test for SVT/VT discrimination when a first predetermined minimum number of ventricular beats occurring after delivery of the cardioversion/defibrillation shock has been judged as normally conducted.