DDD vs. VVI pacing in patients aged over 75 years with complete heart block: a double-blind crossover comparison.

We studied 16 patients aged 77-88 years to determine whether elderly patients gain significant benefit from dual-chamber (DDD) compared with single-chamber ventricular demand (VVI) pacing. The study was designed as a double-blind randomized two-period crossover study--each pacing mode was maintained for 7 days. End points included: (i) overall symptoms scores; (ii) exercise tests related to daily activities; and (iii) perceived level of difficulty (Borg score). The mean symptom score in DDD mode was 7.07 (6.38) vs. 12.27 (7.29) in VVI mode (p < 0.006). Dizziness, breathlessness and fatigue were the most noticed symptoms during VVI pacing. One patient dropped out from follow-up and three patients requested early reprogramming, all from VVI mode. Overall, no patient preferred VVI mode, 11 preferred DDD mode and four expressed no preference. There were significant improvements in all objective test performances in DDD mode. Mean (SD) total Borg scores in DDD mode and VVI mode were 36.57 (5.85) and 41.93 (6.49), respectively (p < 0.002). Ventricular demand pacing in elderly patients with complete heart block is associated with higher symptom scores, reduced exercise ability and greater perceived exercise difficulty compared with dual-chamber pacing.