[Ventricular function in mitral valve prolapse: effects of beta adrenergic blockers with and without intrinsic...

A corollary of the "cardiomyopathy therapy" implies that mitral valve prolapse may cause intrinsic myocardial depression. The impairment of ventricular function may not be detected in basal conditions, but could be unmasked by superimposing depressant factors. The use of beta-blockers constitutes the first choice treatment for the symptomatic management of patients with mitral valve prolapse. Therefore, we tested the hypothesis that myocardial depression could be shown during beta-blockade in the uncomplicated primary form of mitral valve prolapse. The results of echocardiographic and radionuclide angiographic evaluation of left ventricular function during basal conditions, as well as under beta-blockade with propranolol and pindolol, do not lend support to the cardiomyopathy hypothesis of the pathogenesis of primary mitral valve prolapse. However, significant decreases of heart rate, left ventricular ejection fraction and peak velocity of left ventricular systolic emptying were seen with propranolol, but not with pindolol. Beta-blockade with intrinsic sympathomimetic activity may be preferable therapeutic option for patients with mitral valve prolapse.