Calcium antagonist treatment in mild forms of cardiomyopathy.

Twenty-one patients with a mild form of cardiomyopathy (with normal ejection fraction but histologically-confirmed hypertrophy of myocardial cells and/or elevated diastolic pulmonary artery pressure during exercise) received 120 mg verapamil t.i.d. or no therapy at all for a period of 2 months in an open randomized cross-over study. Out of the 21 patients, 14 improved clinically, one patient's condition deteriorated and six remained unchanged (p less than 0.05). The mean diastolic pulmonary artery pressure during exercise decreased (25.3 +/- 7.6 to 20.1 +/- 6.6 mm Hg, n = 21, p less than 0.05). At rest, the decrease was only significant in the subgroup with pressures above 12 mm Hg (15.4 +/- 2.7 to 11.1 +/- 4.1 mm Hg, n = 9, p less than 0.05). All other hemodynamic data displayed no significant change. The benefits of verapamil therapy may be attributed to an improvement in diastolic ventricular function. The disturbance in diastolic relaxation might be of greater importance than the disturbance in systolic function in patients with mild forms of cardiomyopathy.