[Hemodynamics after sublingual administration of captopril in severe heart failure. A pilot study]

In a preliminary trial, 23 patients in severe left-heart failure and, in some instances, also right-heart failure (NYHA classes III and IV) received a single sublingual dose of 25 mg captopril. Invasive measurement of various haemodynamic parameters indicated (1) an increase in cardiac index and stroke-volume index of 34% and 38%, respectively (P less than 0.001 for each); (2) decrease in pulmonary artery and systemic pressures by an average of 7% and 11.4% (P less than 0.01 and less than 0.001, respectively); (3) no significant change in heart rate and mean right atrial pressure; (4) decrease in systemic and pulmonary artery resistance by 33% and 29% (P less than 0.001 for both); (5) an increase in left ventricular stroke work index by 18% (P less than 0.001); and (6) a fall in heart rate x pressure product by 10% (P less than 0.005). These haemodynamic changes started within 12 to 23 minutes after captopril administration, the peak effect occurring between 40 and 90 minutes. Baseline values were reached after three hours. Reproducibility measurements revealed a close quantitative and temporal correlation (r for all greater than 0.8). To obtain similar changes of cardiac function 1.65 micrograms/min.kg sodium nitroprusside were needed. The results indicate that sublingual administration of captopril in severe heart failure will achieve early and significant improvement in cardiac function.