Sotalol vs metoprolol for ventricular rate control in patients with chronic atrial fibrillation who have undergone digitalization: a single-blinded crossover study.

AIMS: To compare the effects of sotalol and metoprolol on heart rate, during isotonic (ITE) and isometric (IME) exercise and daily activities, in digitalized patients with chronic atrial fibrillation.

METHODS AND

RESULTS

The study had a randomized, single-blinded, crossover design. Twenty-three patients with chronic atrial fibrillation received placebo for 4 weeks, followed by a 4-week period of treatment with sotalol and metoprolol in random order. At the end of each period, the patients were assessed with 24-h ECG monitoring, a cardiopulmonary exercise test and a handgrip manoeuvre. Both agents produced a lower heart rate than placebo at rest and at all levels of isotonic exercise (P < 0.001) without affecting oxygen uptake. Sotalol produced a lower heart rate than metoprolol only at submaximal exercise (116 +/- 9 bpm for sotalol vs 125 +/- 11 bpm for metoprolol, P < 0.001). During isometric exercise, sotalol produced a lower maximum heart rate than did metoprolol (113 +/- 22 vs 129 +/- 18 bpm, respectively). Both agents produced a lower mean heart rate than placebo over 24 h (P < 0.001 for all), while sotalol produced a lower mean heart rate than metoprolol during the daytime (P < 0.01).

CONCLUSION

Sotalol is a safe and effective agent for control of heart rate in digitalized patients with atrial fibrillation. Sotalol is superior to metoprolol at submaximal exercise, resulting in better rate control during daily activities.