Comparative Study of Diltiazem, Nitroglycerin, and Sodium Nitroprusside for Controlling Hypertension Following Coronary Artery Bypass Surgery

Hypertension following coronary artery bypass grafting is a common problem. Various drugs are used for the control of hypertension during this period which is known to be vulnerable for postoperative myocardial infarction and bleeding. The aim of this study was to compare the hemodynamic effects of diltiazem, nitroglycerin, and sodium nitroprusside. For this reason 45 patients were equally allocated into 3 groups. In group 1, diltiazem was administered as a 0.3mg/kg IV-bolus within 5 minutes followed by an infusion of 0.1-0.8mg/kg/hr; in group 2, nitroglycerin as a 1-3µg/kg/min infusion, and in group 3 sodium nitroprusside as a 1-3µg/kg/min infusion. Hemodynamic measurements were done before treatment (T1), and 30 min (T2), 2 hours (T3) and 12 hours (T4) thereafter. Mean arterial pressure decreased significantly within all groups (p<0.001). There were no differences between groups at T1 and T2 time points. At T3 time point heart rate was found to be 84±14, 98±13, and 94±15 beats/min in the 3 groups, respectively (group 1 vs 2; p<0.05). Rate-pressure product was 10975±1476 in group 1, 13071±2476 in group 2, 13788±2965 in group 3 (group 1 vs 3; p<0.001). At T4 time point rate pressure product was 10079±1567 in group 1, 12099±2674 in group 2 and 14416±4240 in group 3 (group 1 vs 3; p<0.001). The results of this study suggest that the hemodynamic effects of the three drugs are similar within the first 30 minutes. However, after 30 minutes, diltiazem offers a better myocardial performance and more effective control of hypertension compared to nitroglycerin and nitroprusside.