Effect of disopyramide on left ventricular diastolic function in patients with hypertrophic cardiomyopathy: Comparison with diltiazem

Summary Left ventricular diatolic function before and after the administration of disopyramide (100 mg) or diltiazem (30 mg) was assessed in 10 patients with nonobstructive-type hypertrophic cardiomyopathy. Left ventricular diastolic function was assessed by Doppler echocardiography. The peak early (E) and late (A) diatolic flow velocities and E/A ratio (E/A) were measured. Three hours after the administration of disopyramide, blood pressure did not significantly change, but heart rate was decreased significantly (p<0.01). Disopyramide increased the E velocity and E/A ratio from 43.8±15.0 cm/sec to 51.3±16.1 cm/sec and from 0.71±0.20 to 1.00±0.24 (each p<0.01), respectively, and decreased the A velocity from 63.9±18.5 cm/sec to 52.1±14.9 cm/sec (p<0.01). Diltiazem increased the E velocity and E/A ratio from 42.8±12.5 cm/sec to 46.4±13.4 cm/sec (p<0.05) and from 0.74±0.21 to 0.96±0.28 (p<0.01), respectively, and decreased the A velocity from 60.6±16.4 cm/sec to 50.2±15.6 cm/sec (p<0.01). These results indicate that disopyramide improved left ventricular diastolic filling in hypertrophic cardiomyopathy, and its effect was similar to that of diltiazem.