Effects on left ventricular function of pindolol added to verapamil in hypertrophic cardiomyopathy.

The aim of the study was to assess the effect of adding pindolol to previously used verapamil monotherapy on left ventricular (LV) systolic and diastolic function in 20 patients with hypertrophic cardiomyopathy. Patients were initially treated with verapamil in maximal well-tolerated doses for 16 +/- 14 months; pindolol, 5 mg twice daily, was added. In a Doppler echocardiographic study all patients had altered LV diastolic filling despite verapamil therapy. The control examination, which consisted of echocardiographic study and New York Heart Association functional status classification, was performed after 20 days and repeated after > or = 6 months of follow-up. Combined pindolol and verapamil therapy caused an increase in LV diastolic filling manifested by beneficial changes of transmitral flow parameters. Also, inhibition of hypercontractile LV function expressed by reduction of LV outflow tract pressure gradient and ejection fraction was observed. New York Heart Association functional class was reduced in 13 patients. The magnitude and distribution of LV myocardial hypertrophy did not change significantly. It is concluded that pindolol and verapamil combined therapy is superior to verapamil monotherapy because of improved LV diastolic function (probably due to partial agonist activity of pindolol) and reduced hypercontractile function in patients with hypertrophic cardiomyopathy.