Effect of molsidomine on cardiac preload, coronary artery diameter, and coronary resistance.

The vascular and hemodynamic effects of a single intravenous bolus injection of molsidomine (100 micrograms/kg) were studied in six chronically instrumented, conscious dogs. At this dose only a minimal, short-term effect on peripheral resistance was observed. However, there was a pronounced dilation of peripheral veins and a simultaneous increase of effective vascular compliance of more than 60%. At the same time, central blood volume decreased significantly (17%). Because of preload reduction, left ventricular end-diastolic volume and pressure decreased significantly for more than 1 hour. A significant increase of large coronary artery diameter (up to 7% occurred simultaneously. Coronary resistance vessels were not affected. All effects reached a maximum between 15 and 30 minutes and were observed for at least 4 hours. We conclude that molsidomine exerts a long-lasting effect on the large coronary arteries and on the peripheral venous system. As a result of the combined effects on cardiac preload and on epicardial artery conductance, the myocardial oxygen supply and the supply/demand ratio will be improved.