Dual chamber rate responsive pacemaker with variable refractory period

摘要

An improved atrial synchronous, dual chamber pacemaker provided with a variable refractory period during which the pacemaker is not responsive to the sensed atrial contractions. The atrial refractory period is varied as a function of measured atrial and ventricular rates, and corresponds to a predetermined proportion of the lesser of the average interval separating the ventricular contractions and the average interval separating atrial contractions. The invention is particularly beneficial in the context of a VDD type pacemaker.