[Doppler and echocardiographic assessments of effects of disopyramide on non-obstructive hypertrophic cardiomyopathy]

Abstract

We assessed the effects and therapeutic implications of disopyramide on left ventricular systolic and diastolic functions in 19 patients with non-obstructive hypertrophic cardiomyopathy by Doppler echocardiography. All patients were in sinus rhythm. Parameters measured were fractional shortening (FS (%)), mean velocity of circumferential fiber shortening (mean Vcf (circ/sec)), ejection fraction (EF (%)), peak left ventricular outflow velocity (peak-LVOT (cm/sec)), peak rapid filling inflow velocity (peak-R (cm/sec)), peak late filling inflow velocity (peak-A (cm/sec)) and peak-A/peak-R ratio (A/R ratio). These values were compared before and after infusion of disopyramide (2 mg/kg). There was no significant difference in heart rate, systolic and diastolic blood pressures before and after infusion of disopyramide. Following the intravenous drip infusion of disopyramide, FS decreased from 38.1 +/- 5.4 to 33.2 +/- 4.9 (p less than 0.05) and the mean Vcf decreased from 1.285 +/- 0.181 to 1.141 +/- 0.188 (NS). EF and peak-LVOT also decreased from 67.7 +/- 6.3 to 61.9 +/- 7.0 (p less than 0.05), and from 107.6 +/- 29.5 to 92.4 +/- 25.2 (p less than 0.01), respectively. The infusion of disopyramide increased the peak-R from 47.3 +/- 18.2 to 55.5 +/- 19.2 (p less than 0.05), and decreased peak-A from 52.0 +/- 13.6 to 40.2 +/- 12.6 (p less than 0.01), resulting in a decrease of A/R ratio from 1.277 +/- 0.537 to 0.818 +/- 0.475 (p less than 0.01). These results suggest that disopyramide improved left ventricular diastolic function, although systolic function decreased slightly. In conclusion, disopyramide can be also used beneficially in non-obstructive hypertrophic cardiomyopathy without arrhythmias.