Assessment of the hemodynamic response to acetyl-strophanthidin by Doppler echocardiography in normal subjects and in those with coronary artery disease or idiopathic dilated cardiomyopathy

Abstract

The effect of acetyl-strophanthidin, a rapidly acting digitalis-like drug, was measured on peak flow velocity, stroke distance (an index of stroke volume) and minute distance (an index of cardiac output), determined by Doppler echocardiography in 21 subjects with a wide range of left ventricular ejection fractions (12 to 89%, average 47%). For the total study group, peak flow velocity increased from 99 ± 10 to 110 ± 13 cm/s (p < 0.01), and stroke distance increased from 15.1 ± 3.2 to 16.8 ± 3.1 cm (p < 0.01). Minute distance remained unchanged: 1,093 ± 168 cm before and 1,129 ± 187 cm after acetyl-strophanthidin (difference not significant). Improvement in Doppler parameters of forward blood flow was significantly (p < 0.001) greater in subjects with left ventricular ejection fractions <60% (+17% for peak flow velocity, +22% for stroke distance and +15% for minute distance) than in those with left ventricular ejection fractions ≥60% (+4% for peak flow velocity, +2% for stroke distance and −8% for minute distance). These data suggest that Doppler echocardiography is a useful method to assess the efficacy of acute digitalis administration in improving forward blood flow.