Patent ID: 7076300

Claim:
An implantable cardiac stimulation device that treats accelerated arrhythmias of atria of a patient's heart, the device comprising: a sensing circuit that senses cardiac activity of one of the patient's atria to provide an atrial activity signal; a detector that detects an accelerated atrial arrhythmia of the patient's heart; a classifying circuit that measures relative correspondence between a plurality of pairs of successive P waves of the atrial activity signal to classify the detected accelerated atrial arrhythmia as either atrial tachycardia or atrial fibrillation; and a therapy circuit that applies a first therapy to the heart responsive to a classified atrial tachycardia and a second therapy to the heart responsive to a classified atrial fibrillation; wherein the relative correspondence is determined by an auto-power spectra computed as a discrete-time cosine transform.