Comparative investigations on the cardiovascular effects of Org NC45 and pancuronium in dogs.

Cardiovascular effects of Org NC 45 and pancuronium were examined in seven anaesthetized dogs. Systemic circulatory effects were measured after increasing doses administered as a single i.v. bolus. Cardiac effects were measured after intracoronary (i.c.) injection of the equivalent dose of the respective neuromuscular blocking agent, which produced 90% neuromuscular blockade. Org NC 45 i.v. did not cause any significant cardiovascular changes, whereas pancuronium i.v. produced significant and dose-related increases in heart rate, left ventricular (LV) dP/dtmax and cardiac output (CO). After i.c. injection of equipotent doses, neither drug induced any significant change in haemodynamic measurements. This implies that neither drug exerted a direct influence on cardiac contractility, the increases in LV dP/dt max and CO following pancuronium being dependent on heart rate.