Acute Systeinic and Coronary Hemodynamic Effects of Trimethidinium Methosulfate.∗

1. The acute hemodynamic effects of trimethidinium methosulfate have been studied in 10 mongrel dogs. 2. Administration of the drug results in a decrease in blood pressure in the systemic and pulmonary arteries and the right atrium. 3. Associated with these decreased pressures, the stroke volume decreased, but there was sufficient increase in cardiac rate so that cardiac output did not change significantly. Pulmonary vascular resistance decreased significantly where as peripheral resistance fell slightly but not significantly. 4. Both right and left ventricular work decreased significantly while left ventricular myocardial oxygen consumption was unchanged and calculated cardiac efficiency decreased. 5. These hemodynamic effects are similar to those of hexamethonium, pentolinium, mecamylamine and SKF 6890.