Effects of acute administration of gallopamil on left ventricular relaxation and filling dynamics in acute myocardial infarction assessed by doppler echocardiography
The purpose of this study was to assess the acute effect of an intravenous bolus of the calcium antagonist gallopamil on left ventricular diastolic function using Doppler echocardiography. Fifteen patients with acute myocardial infarction in the first Killip class and sinus rhythm were randomized to an intravenous bolus of gallopamil (50 μg/kg over 5 minutes) or placebo in a crossover sequence. Doppler echocardiography was performed at baseline and 15 minutes after each bolus. No patients had received calcium antagonists or beta blockers before the study; all patients received nitroglycerin, which was withdrawn at least 2 hours before the baseline Doppler echocardiogram. The following Doppler parameters were calculated: the early (E) and late (A) peak filling velocities, the velocities ratio (E/A), the diastolic filling time-velocity integral (TVI), the peak filling rate normalized to the mitral stroke volume (nMPFR), the isovolumic relaxation time (IVRT), and the systolic flow velocity integral (SFVI). Expressing the parameters measured after a gallopamil bolus as the percent change of those measured after placebo, E, E/A, and nMPFR increased by 25.5±11.5%, 30.6±15.5%, and 19.0±12.2%, respectively (p<0.001); IVRT decreased by 13.5±7.0% (p<0.001); and TVI increased mildly by 6.9±9.9% (p=0.01). SFVI and A did not change significantly. Negligible differences were observed between placebo and baseline values. Heart rate, mean blood pressure, and left ventricular and atrial diameters did not change significantly. It was concluded that gallopamil infusion improves early left ventricular filling and relaxation in patients with acute myocardial infarction. Considering the unchanged loading conditions, this indicates an improvement in left ventricular diastolic performance.