Effect of atrial fibrillation on exercise capacity in mitral stenosis.

To determine the preoperative and postoperative effect of atrial fibrillation (AF) on exercise capacity in mitral stenosis, 12 digitalized patients in AF (7 women and 5 men, age 52 +/- 6.1 years) and 10 in sinus rhythm (5 women and 5 men, age 46 +/- 5 years) underwent maximal cardiopulmonary exercise testing according to Weber's protocol and Doppler echocardiographic examination before and at 3 and 6 months after mitral valve replacement. The ratio of right ventricular acceleration to ejection time was used as an estimate of mean pulmonary artery pressure. Preoperative exercise duration (6.8 +/- 1 vs 8 +/- 2 minutes), peak oxygen consumption (9.7 +/- 3 vs 12.3 +/- 3 ml/kg/min), and right ventricular acceleration to ejection time ratio (0.34 +/- 0.07 vs 0.34 +/- 0.08) were not significantly different between patients with AF and those in sinus rhythm. Postoperative improvement in these parameters was lower in patients with AF than in those in sinus rhythm: exercise duration at 3 months, 7.5 +/- 2 vs 11.9 +/- 2 minutes (p < 0.001); at 6 months, 9 +/- 2 vs 12 +/- 2 minutes (p < 0.001); peak oxygen consumption at 3 months, 10.8 +/- 3 vs 17.5 +/- 3 ml/kg/min (p < 0.001); and at 6 months, 11.9 +/- 3 vs 17.8 +/- 3 ml/kg/min (p < 0.001); right ventricular acceleration to ejection time ratio at 3 months, 0.35 +/- 0.08 vs 0.42 +/- 0.05 (p < 0.05); and at 6 months, 0.38 +/- 0.05 vs 0.44 +/- 0.05 (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)