Effect of disopyramide on left ventricular pressure gradient in hypertrophic obstructive cardiomyopathy in comparison with propranolol--a case report.

The effect of intravenous administration of disopyramide (total dose 100 mg, bolus 20 mg every 5 minutes) was compared with that of propranolol (total dose 10 mg, bolus 2 mg every 5 minutes) in a patient with hypertrophic obstructive cardiomyopathy. Left ventricular pressure gradient (LVPG) was assessed by continuous wave Doppler flowmetry. LVPG markedly decreased (97 to 16 mmHg), and preejection period (PEP) increased with an increase in heart rate (HR) during disopyramide injection. No changes were observed in LVPG and PEP, and a decrease occurred in HR during propranolol administration. These results indicate that disopyramide produced greater effects on the reduction of LVPG than propranolol, a negative inotropic agent, did.