Far-field QRS complex sensing: prevalence and timing with bipolar atrial leads.

Sensing of far-field QRS complex through the atrial pacemaker lead may cause a number of pacemaker function disturbances, most of which are rarely seen with modern pulse generators. However, certain pulse generator algorithms will still be jeopardized by far-field QRS complex sensing. Intracardiac electrograms with markers were obtained by telemetry in 30 patients following implantation of a permanent bipolar atrial lead and a DDDR pulse generator.

Facilitation of DDD follow-up using the DDT mode.

To facilitate follow-up, modern dual chamber pacemakers provide a variety of diagnostic features like ECG interpretation channels and intracardiac electrograms. For evaluation of the sensing performance at rest and during exercise, for assessment of the presence of crosstalk, and for measurement of the retrograde conduction time, dual chamber triggered pacing, particularly the DDT mode, can be used alternatively or additionally in pacemakers equipped with this option. In contrast to ECG interpretation channels, ECG documentation is not required for evaluation of the sensing performance, because the triggered pulses serving as markers for sense events can also be seen on the monitor.