Patent ID: 7317942

Claim:
A medical device for discriminating arrhythmia events, comprising: an input circuit sensing cardiac signals; a microprocessor identifying an event associated with the sensed cardiac signals as a first arrhythmia event; a first circuit delivering a first therapy, substantially simultaneous with coupling of a charging circuit and an energy storage device to generate stored energy on the energy storage device, in response to the first arrhythmia event; and a control circuit controlling delivery of the first therapy by the first circuit, wherein the microprocessor evaluates a physiologic response to the delivered first therapy and determines the event is other than the first arrhythmia event in response to the evaluated physiologic response, wherein the microprocessor determines whether an interval pattern during the first arrhythmia event corresponds to a predetermined pattern, and determines whether a difference between a cycle length corresponding to sensed cardiac signals during the first arrhythmia event prior to delivery of the first therapy and a cycle length corresponding to sensed cardiac signals during delivery of the first therapy is less than or equal to a predetermined threshold.