Patent ID: 7856267

Claim:
A method for operating a cardiac pacemaker, comprising: sensing atrial depolarizations through an atrial sensing channel; sensing ventricular depolarizations through one or more ventricular sensing channels; pacing a ventricle in accordance with a particular primary pacing mode that delivers paces to only one ventricle; switching the pacemaker to an atrial fibrillation pacing mode upon detection of an atrial tachyarrhythmia, wherein the atrial fibrillation mode includes a biventricular pacing mode that delivers paces to both left and right ventricles in a non-atrial triggered pacing mode and adjustment of a ventricular escape interval in order to regularize the rate at which ventricular beats occur; and, wherein the adjustment of the ventricular escape interval increases the ventricular escape interval after each ventricular pace is delivered and decreases the ventricular escape interval after each ventricular sense.