EFFECT OF ATRIAL-FIBRILLATION ON EXERCISE CAPACITY IN MITRAL-STENOSIS

To determine the preoperative and postoperative effect of atrial fibri llation (AF) on exercise capacity in mitral stenosis, 12 digitalized p atients in AF (7 women and 5 men, age 52 +/- 6.1 years) and 10 in sinu s rhythm (5 women and 5 men, age 46 +/- 5 years) underwent maximal car diopulmonary exercise testing according to Weber's protocol and Dopple r echocardiographic examination before and at 3 and 6 months after mit ral valve replacement. The ratio of right ventricular acceleration to ejection time was used as an estimate of mean pulmonary artery pressur e, 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 ven tricular 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 w as lower in patients with AF than in those in sinus rhythm: exercise d uration at 3 months, 7.5 +/- 2 vs 11.9 +/- 2 minutes (p < 0.001); at 6 months, 9 +/- 2 vs 12 +/- 2 minutes (9 < 0.001); peak oxygen consumpt ion at 3 months, 10.8 +/- 3 vs 17.5 +/- 3 ml/kg/min (9 < 0.001); and a t b months, 11,9 +/- 3 vs 17.8 +/- 3 ml/kg/min (9 < 0.001); right vent ricular deceleration 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). Peak oxygen: consumption was directly related to r ight acceleration to ejection time ratio both in patients with AF (r = 0.67) and in those in sinus rhythm (r = 0.77), Thus, AF is not associ ated with a further decrease in exercise capacity in digitalized patie nts with severe mitral stenosis but adversely affects the postoperativ e improvement in their exercise capacity after mitral valve replacemen t.