Patent ID: 7537569

Claim:
A method of identifying a cardiac event, comprising: detecting sensed events using a first detection format in a first state during detection of other than the cardiac event; advancing from the first state to a second state corresponding to suspending the detecting using the first detection format and detecting sensed events using a second format different from the first detection format in response to the first detection format determining the sensed events correspond to the cardiac event while in the first state; advancing from the second state to the first state in response to the second detection format determining the sensed events do not correspond to the cardiac event while in the second state; advancing from the second state to a third state in response to the second detection format determining the sensed events correspond to the cardiac event while in the second state, the third state corresponding to detecting sensed events using the first detection format; advancing from the third state to a fourth state in response to the sensed events being determined not to correspond to the cardiac event while in the third state, the fourth state corresponding to suspending the detection using the first format and detecting sensed events using the second detection format; advancing from the fourth state to the third state in response to the sensed events being determined to correspond to the cardiac event while in the fourth state; and advancing from the fourth state to the first state in response to the sensed events being determined not to correspond to the cardiac event while in the fourth state.