A study of lipid peroxide and alpha tocopherol in acute myocardial infarction.

Thirty patients of acute myocardial infarction proven by electrocardiography (ECG) and enzymes were included in the study. All of them received streptokinase. A single lead showing the largest ST elevation, a proportional value for the shift in ST segment > or = 0.5 was taken as criteria for reperfusion. ECG was recorded at 0 hour, 3 hours and 72 hours. At the start of streptokinase and 3 hours after, marker of free radical activity malondialdehyde (MDA) and antioxidant alpha tocopherol was measured. Mean value of serum alpha tocopherol level at start of streptokinase (t0) 10.03 +/- 2.5 micrograms/ml and at (t3) 3 hours after streptokinase was 8.60 +/- 2.6 micrograms/ml (P < 0.001) and mean value of serum lipid peroxidation level was 6.86 +/- 2.92 nanomol/ml at t(o) and at t3 value was 8.4 +/- 3.88 (P < 0.012) in successfully reperfused patients. In unsuccessful reperfusion group serum alpha tocopherol level at t(o) was 8.89 +/- 2.55 micrograms/ml and at t3 8.23 +/- 2.9 micrograms/ml (p > 0.05). Serum lipid peroxidation level in the same group at t0 was 6.53 +/- 2.26 nanomol/ml and at t3 was 6.29 +/- 2.27 nanomol/ml (p > 0.05). The increase in free radical marker MDA and decrease in one of the important antioxidant alpha tocopherol suggest that free radicals are increased after coronary vessels open up. As a result reperfused patients may be at risk of free radical mediated injury which may deny him the full benefit of reperfusion.