The role of oxygen free radicals in reperfusion injury to the heart during thrombolytic therapy in myocardial infarction (M.I.) has been postulated. In this study, the clinical and antioxidant effects of esmolol, an ultra-short acting beta blocker in patients of acute M.I. were studied.
This was a randomized, double-blind, controlled, prospective study. Total 30 patients with acute M.I. were included. All patients were thrombolysed with streptokinase. Fifteen of these patients were randomly selected to receive esmolol while other 15 patients served as controls. The parameters compared at 0, 2 and 24 hours between the esmolol group and the controls were: malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX).RESULTS: Patients with M.I. had 5.16 times higher MDA level at 0 hours (20.34±6.12 nmol/ml vs. 3.94±0.70 nmol/ml, p<0.0001) than MDA level in normal healthy population. At 2 hours, patients with M.I. had 5.71 times higher MDA level compared to normal healthy population (22.51±5.51 nmol/ml vs. 3.94±0.70 nmol/ml, p<0.0001). A statistically significant difference in MDA levels at 2 and 24 hours was observed in M.I. patients given esmolol (mean change 2.06±5.39 nmol/ml vs. −4.47±6.93 nmol/ml, p =0.009). Esmolol infusion also caused significant difference in GPX level at 2 hours compared to controls (23.79+14.68 U/gm Hb vs 38.3±8.95 U/gm Hb, p=0.003).CONCLUSIONS: Free radical levels are raised in patients with M.I. which may contribute to reperfusion injury. The antioxidant action of esmolol was clearly observed by significant difference in MDA level and GPX sparing effect.CLINICAL IMPLICATIONS: Esmolol has significant antioxidant and myocardial protective effect in acute M.I. Esmolol has potential role as antioxidant as adjuvant to thrombolytic therapy in M.I. in future.
B. Sharma, None.