Physiologic cardiac pacing in patients with contemporary implantable cardioverter-defibrillators

Contemporary implantable cardioverter-defibrillators (ICD) incorporate single-chamber ventricular pacing capability. However, because poor ventricular function and/or congestive heart failure is common in the ICD population, the provision of more “physiologic” pacing modes has been receiving increased attention. To evaluate the potential impact of ICDs with physiologic pacing features, we assessed the frequency with which atrial-based pacing modes with or without rate responsiveness are currently used in ICD recipients. Further, we characterized those clinical variables at initial ICD implant that tended to be associated with subsequent need for physiologic pacing. Clinical findings were reviewed in 250 consecutive patients who received ICDs with VVI pacing capability at the University of Minnesota Cardiac Arrhythmia Center between January 1991 and February 1997. Adjunctive physiologic pacing was undertaken in 35 patients (14%): 13 before or at the same time as their ICD, and 22 within a mean of 2.5 years after initial ICD surgery. A history of atrial tachyarrhythmia before ICD implantation (p