Patent ID: 8831723

Claim:
A cardiac medical device for delivering anti-tachycardia pacing, comprising: a plurality of electrodes implantable within a patient for sensing cardiac signals and delivering cardiac pacing pulses; a therapy delivery module coupled to the plurality of electrodes for delivering pacing pulses to the patient's heart via the plurality of electrodes; and a controller coupled to the therapy delivery module and adapted to be electrically connected to the plurality of electrodes, the controller configured to: detect a tachycardia episode from the cardiac signals, control the therapy delivery module to deliver, via the plurality of electrodes, a plurality of dual chamber pacing pulses in response to detecting the tachycardia episode; in response to sensing an earliest occurring intrinsic event in a first cardiac chamber, identify a plurality of cardiac cycles in the first cardiac chamber comprising the earliest occurring sensed intrinsic event and a predetermined number of subsequent sensed intrinsic events occurring in the first cardiac chamber subsequent to the dual chamber pacing pulses; determine how many sensed intrinsic events occur in a second cardiac chamber during the plurality of cardiac cycles in the first chamber as a number of second chamber events; and classify the detected tachycardia episode as originating in the second cardiac chamber in response to the earliest occurring intrinsic event in the first cardiac chamber and the determined number of second chamber events being greater than the predetermined number of subsequent sensed intrinsic events occurring in the first cardiac chamber during the identified plurality of cardiac cycles in the first chamber.