[Effects of captopril on the myocardial performances and hemodynamics after cardiac arrest]

The effects of cardioplegia and reperfusional blood containing 4.6 mumol/L captopril (CPL) on the myocardial performances and hemodynamics of canine heart under hypothermic extracorporeal circulation were studied. Twenty four mongrel dogs were divided randomly into 3 groups.

Only modified St. Thomas cardioplegia was used. CPL group: St. Thomas cardioplegia containing CPL 4.6 mumol/L was used and the same concentration of captopril in the circulatory blood was established before releasing the cross clamp. CPL + phenylephrine group: The concentration was the same as the CPL group, with an additional dose of phenylephrine (2 micrograms/kg) into the oxygenator and abdominal coarctation. The results revealed that the coronary blood flow and left ventricular contractility and relaxation indices of CPL group were significantly improved than those of the control group, and increasing the systemic and pulmonary vascular resistence had no effect on the cardiac function protected by captopril. It is suggested that captopril could ameliorate the recovery of myocardial performences by inhibitting myocardial and systemic renin-angiotensin system and scavenging free radicals.