Pacemaker troubleshooting: improved efficacy using a new diagnostic digital Holter recording system.

Asymptomatic dysfunction of cardiac pacing systems is not uncommonly detected using long-term ambulatory monitoring techniques. We report two patients with atrial and ventricular sensing abnormalities noted only on Holter monitoring. Multiple empirical attempts at pacemaker reprogramming based on deductive analysis of the pacing anomaly were unsuccessful. Through the use of a new digital recording system that allowed collection of surface electrocardiographic data, intracardiac electrograms, and Marker Channel data a correct diagnosis was made (pacing lead insulation failure). This new recording system has the advantage of significantly improving diagnostic sensitivity and resulting in cost savings.