Denopamine augments the left ventricular pump function in infants with ventricular septal defect and pulmonary hypertension: Doppler echocardiographic analysis.

The purpose of this study is to evaluate hemodynamic effects and clinical benefit of oral denopamine in infants with left to right shunt disease. We measured heart rates, left ventricular end-diastolic and end-systolic dimensions, shortening fractions, peak and mean flow velocities of the main pulmonary artery and ascending aorta at 30, 60 and 90 min after oral denopamine using Doppler echocardiography. Seventeen infants with ventricular septal defect and pulmonary hypertension (mean pulmonary artery pressures higher than 25 mmHg) were divided into two groups depending upon the doses of denopamine; group 1 received 1 mg/kg, and group 2 was given 0.5 mg/kg. Serum concentrations of denopamine were measured with high performance liquid chromatography after completion of these evaluations. In both groups, heart rates and left ventricular shortening fractions increased, and left ventricular end-systolic dimensions decreased significantly. Although peak and mean velocities of aortic and pulmonary flows increased significantly, there were no significant alterations in peak and mean velocity ratios of pulmonary to aortic flow. There was no significant difference in the serum concentration of denopamine between the two groups. However, percentage changes of some indices, such as heart rates, left ventricular end-systolic dimensions, peak aortic and pulmonary flow velocities, and mean aortic flow velocities exponentially correlated to serum concentrations of denopamine. In conclusion, denopamine is supposed to have beneficial actions to augment the systemic output by enhancing the left ventricular pump function in patients of ventricular septal defect. However, we should be careful for denopamine not to produce excessive increases in heart rate and pulmonary blood flow.