Beta-Blockade and Exercise Capacity in Patients with Mitral Stenosis in Sinus Rhythm
J. V. Monmeneu Menadas MD, F. Marín Ortuño MD, F. Reyes Gomis PhD, A. Jordán Torrent MD, M. García Martínez MD, V. Bodí Peris MD, F. García de Burgos de Rico PhD

This prospective study compared the results of cardiopulmonary exercise tests (Naughton protocol) performed before and after one-week atenolol therapy (50 mg/day) in 17 patients in NYHA classes I and II with mitral stenosis in sinus rhythm. Maximum O2 uptake (VO2max) did not differ significantly before or after beta-blockade. Heart rate at rest and during peak exercise, and anaerobic threshold were lower with beta-blockade compared with baseline state. Minute ventilation at maximum exercise and ventilatory equivalent for CO2 were unchanged with atenolol therapy, indicating no improvement in ventilatory performance. Some patients felt symptomatically worse during atenolol treatment (lower NYHA class). Thus, beta-blockade did not improve exercise tolerance in patients with mitral stenosis in sinus rhythm. In addition, ventilatory performance does not change with treatment.