A
system and method which employs atrial discrimination algorithms to distinguish between different
atrial arrhythmias occurring in a patient for selecting an optimal pacing therapy corresponding to the type of arrhythmia identified. The invention may be implemented in a
bradycardia pacemaker or other implantable
cardiac device. In response to the detection of an
atrial rate above the atrial tracking rate, discrimination criteria are applied to a detected atrial activity
signal to distinguish between different types of
supraventricular tachycardia, such as fast
atrial flutter and other
atrial flutter at a relatively slower rate, which may be occurring in the patient. The discrimination criteria may be, for example, rate-based or morphology based. The pacer is controlled to provide pacing therapy to a heart in a manner corresponding to the type of
supraventricular tachycardia identified. For example,
antitachycardia pacing may be provided to the heart in response to the detection of a relatively lower rate
supraventricular tachycardia / other
atrial flutter, whereas another pacing control, e.g.,
ventricular pacing, such as
ventricular rate regulation or Rate
Smoothing, may be applied if a more
rapid rate supraventricular
tachycardia / fast atrial
flutter is identified. The output of an atrial discrimination
algorithm may be tracked and the trend thereof used to improve therapy timing.