The effect of perioperative use of Sodium nitroprusside (SNP) was reviewed in 20 patients undergoing mitral valve replacement. 0.01% SNP was used for intravenous infusion with an average dose of 1.15 + 0.57 ug/kg/min. Intravenous GIK was used also preoperatively to improve myocardial energy reserve and cardiac function. SNP helps to improve cardiac output by reducing renin-angiotensin activity and lowering both the systemic arterial and the pulmonary arterial pressure so as to lessen the preload as well as the afterload of the heart. Low dose dopamine was used in company with SNP after bypass if necessary. It helps to improve myocardial contractility

and to prevent low-cardiac output syndrome. Blood volume should be adequately supplemented before SNP infusion. Hemodynamic changes should be watched carefully during infusion of SNP

and potassium administered according to the urinary output. Effect of perioperative use of SNP was found satisfactory in mitral valve replacement