Patent ID: 6522917
Filing Date: 2003-02-18
Classification: A61N

Abstract:
A system, comprising:an atrial lead and a ventricular lead, where the atrial lead includes an atrial pacing/sensing electrode and the ventricular lead includes a defibrillation electrode and a ventricular pacing/sensing electrode; control circuitry coupled to the atrial pacing/sensing electrode, the defibrillation electrode and the ventricular pacing/sensing electrode, where the control circuitry receives signals indicating atrial contractions and ventricular contractions, and where the control circuitry includes: a ventricular contraction detector circuit to detect the occurrence of the ventricular contractions; an atrial contraction detector circuit to detect the occurrence of the atrial contractions; a cardiac data analyzing circuit coupled to the ventricular contraction detector circuit and the atrial contraction detector circuit, where the cardiac data analyzing circuit calculates atrial cycle lengths from the detected atrial contractions and ventricular cycle lengths from the detected ventricular cycle lengths and analyzes the ventricular contractions for the occurrence of a tachycardia episode, and when the tachycardia episode occurs the cardiac data analyzing circuit analyzes the ventricular contractions and the atrial contractions to determine whether a one-to-one association of atrial contractions to ventricular contractions exists; a cycle length pairing circuit coupled to the cardiac data analyzing circuit, where the cycle length pairing circuit pairs the atrial cycle lengths and the ventricular cycle lengths in an antegrade direction and a retrograde direction when the cardiac data analyzing circuit determines the tachycardia episode has the one-to-one association of atrial contractions to ventricular contractions; and a microprocessor coupled to the cycle length pairing circuit, where the microprocessor determines a retrograde correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the retrograde direction and an antegrade correlation coefficient for the atrial cycle lengths paired with the ventricular cycle lengths paired in the antegrade direction, and where the microprocessor classifies the tachycardia episode based on a comparison of the antegrade correlation coefficient and the retrograde correlation coefficient.