Patent ID: 7228176

Claim:
A system comprising: an atrial contraction detector circuit, including an atrial rate detector circuit to detect an atrial rate between atrial contractions of a heart; a ventricular contraction detector circuit, including a ventricular rate detector circuit to detect a ventricular rate between ventricular contractions of the heart; and a processor, coupled to the atrial and ventricular rate detector circuits, the processor including: a tachyarrhythmia detection module; and a tachyarrhythmia classification module including a first comparator for determining if the ventricular rate exceeds the atrial rate by a threshold value, in which the threshold value varies as a function of at least one of the atrial rate and the ventricular rate, and in which if the ventricular rate exceeds the atrial rate by the threshold value corresponding to the at least one of the atrial rate and the ventricular rate, then deeming the tachyarrhythmia to be a ventricular tachyarrhythmia.