Patent ID: 7031771

Claim:
An implantable medical device, comprising: means for sensing cardiac events; means for applying interval only logic steps to determine cardiac rhythms in response to the sensed cardiac events; means for combining morphology based considerations of the cardiac rhythms with the interval only logic steps to achieve improved specificity in arrhythmia detection of the apparatus without loss of sensitivity; means for generating a VT (ventricular tachycardia) count; and means for delivering therapy in response to the means for combining, wherein, in response to interval only logic steps corresponding to SVT (supraventricular tachycardia) rejection not being satisfied, the combining means determines whether the cardiac rhythms have a morphology that corresponds to sinus rhythm, therapy is delivered by the delivery means in response to the cardiac rhythms having a morphology that does not correspond to sinus rhythm and therapy is withheld by the delivery means in response to the cardiac rhythms having a morphology that corresponds to sinus rhythm, and wherein the generating means resets the VT count in response to the therapy being withheld by the delivery means in response to the cardiac rhythms having a morphology that corresponds to sinus rhythm.