A dual chamber pacemaker incorporating a system for distinguishing Wenckebach episodes from pacemaker mediated tachycardia episodes based on variations in VA intervals is disclosed which provides for adjusting the MTR upward in response to a threshold frequency of incidences of Wenckebach....http://www.google.de/patents/US6216035?utm_source=gb-gplus-sharePatent US6216035 - Determination of pacemaker wenckebach and adjustment of upper rate limit
