Fluctuations of the atrial cycle length and A-V delay with a universal (DDD) pacemaker

The electronic characteristics of a new universal (DDD) pulse generator can result in significant shortening of the atrial cycle length (A-A interval) and shortening of the atrioventricular (A-V) interval beyond the programmed values. These pacemaker arrhythmias are entirely compatible with normal function and must not be interpreted as malfunctions.