Patent ID: 7024243

Claim:
In an implantable cardiac stimulation device having a biventricular pacing system and a PMT detection and termination system for implant within a patient, a method comprising: delivering a pair of biventricular pacing pulses to the left and right ventricles of the heart of the patient using the biventricular pacing system; detecting PMT using the PMT detection and termination system; and controlling the biventricular pacing system using the PMT detection and termination system to terminate the PMT; wherein detecting PMT comprises: detecting intervals between ventricular pulses (V-pulses) and subsequent atrial depolarization signals within the atrial and ventricular channel signals; determining a degree of variation within the intervals; and identifying PMT based on the degree of variation in the intervals; and wherein identifying PMT based on the degree of variation in the biventricular pacing intervals further comprises: determining, based on the V-pulse to atrial depolarization signal intervals, when a next expected atrial depolarization signal should occur; delivering a pacing pulse to the atria prior to the next expected atrial depolarization signal timed to render the atria refractory during the next expected atrial depolarization signal; and if an atrial depolarization signal nevertheless occurs at the expected time, verifying that PMT is occurring; otherwise concluding that PMT has not occurred.