Failure of propranolol to improve exercise tolerance in patients with mitral stenosis in sinus rhythm.

Abstract

SUMMARY Propranolol reduces left atrial pressure at rest and during exercise in patients with mitral stenosis by lowering cardiac output and heart rate. Ten patients (aged Propranolol did not improve objective or subjective exercise tolerance in patients with isolated mitral stenosis in sinus rhythm.The potential beneficial effect of, blockade in patients with mitral stenosis has been studied over the past 20 years.' -3 The rationale for these investigations was the understanding that the pressure gradient across a stenotic mitral valve rises exponentially as the heart rate and cardiac output increase.4 Thus the increases in heart rate and cardiac output that occur during exercise lead to higher left atrial and pulmonary venous pressure, which are the presumed cause of the exertional dyspnoea of mitral stenosis.5 ,B blockade, by blunting the rises in heart rate and cardiac output during exercise, and thereby increasing the diastolic filling period and reducing transvalvar flow, would be expected to reduce the increase in pulmonary venous pressure at any given level of exercise. Indeed, in studies in which intravenous pronethalol' or propranolol2 3 were given to patients with mitral stenosis during diagnostic car-

Effects of chronic β‐blockade on rest and exercise hemodynamics in mitral stenosi

“…Investigators who favor the use of (3-blockers in mitral stenosis generally report improved pulmonary capillary wedge pressure as a consequence of the beneficial action of P-antagonists [1,2,5,151. Although some investigators have suggested that ex- ercise performance is improved with P-antagonists [4,15], others have shown, in double-blind randomized placebo-controlled trials, no objective or subjective benefit in exercise performance [7]. Our results are similar to the results of Giuffrida et al [2], who reported that although propranolol reduced the gradient across the mitral valve during exercise, patients did not have an increase in exercise capacity.…”

“…Furthermore, because stroke volume was little changed, the paradoxic effects of beta blocker therapy became apparent, since the benefit of reduced PCWP is offset by lost cardiac reserve ( 1 CO = 4 HR X -SV). These observations may explain the disparate finding in exercise response reported by others [4,7,15].…”

Reliability and Efficacy of Metoprolol and Diltiazem in Patients Having Mild to Moderate Mitral Stenosis with Sinus Rhythm

“…Contradictory results are reported on this subject from studies in the literature. [11][12][13][14][15] Cumming and Car 14 suggested that although beta blockers decrease the transmitral gradient, they also cause a decrease in cardiac performance in general and so they have no place in the treatment of MS. They related this to augmentation of left ventricular EDP by beta blockers by decreasing the cardiac output.…”