Does rate-responsive pacing improve exercise capacity, symptomatology, and quality of life compared to constant rate pacing in patients with pacemakers for heart block or sick sinus syndrome?
Rate-responsive pacing significantly improves exercise capacity and specific symptoms like shortness of breath and energy levels compared to constant rate pacing.
Although the hemodynamic advantages of rate-responsive (RR) pacing are well established, the symptomatic benefits remain controversial and the effects on the quality of life have not been assessed. Sixteen patients with RR pacemakers and a mean age of 56 (range 22-77) years were involved in a double-blind crossover study to assess their exercise capacity (treadmill testing), symptomatology, and quality of life (structured questionnaires). Pacemakers were implanted because of symptomatic heart block or sick sinus syndrome. Ventricular demand pacemakers were randomly programmed into the constant rate (VVI) or RR pacing modes for four-week study periods. All patients exercised longer in the RR mode than in the VVI mode (570 +/- 29 vs. 437 +/- 17 s, p less than 0.001). Statistically significant improvements in "shortness of breath" and "energy during daily activities" as measured by a 10-point scale were reported in the RR pacing mode by the patients and were also observed by their close relatives. Symptoms such as "chest pain" and "palpitations" were not worsened during RR pacing. Nondisease-specific "quality of life" was studied in 11 patients using the Nottingham Health Profile which showed a trend for an improved quality of life in five of the six dimensions of perceived health, although none of the changes were statistically significant. This study suggests that RR pacing should be recommended in selected patients on symptomatic grounds.
Lau et al. (Fri,) studied this question.
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