RESUMO
An attack of acute myocardial infarction [MI] poses the threat of great damage to cardiac tissue. Operative therapeutic modalities such as coronary artery bypass grafting [CABG] may enhance myocardial perfusion in high-grade coronary vasculature occlusions. It has been shown previously that Low-Level Laser Therapy [LLLT] significantly reduces infarct size following induction of myocardial infarction in rats and dogs. The aim of this study was to investigate the effects of LLLT on cardiac tissue healing markers following grafting operations for coronary vessel occlusion. Thirty-two cases having each two or three coronary vessel occlusions [2VD/3VD] underwent low-level laser therapy post-CABG, and 28 patients who did not undergo laser therapy were studied as a control group. Diode laser [810 nm, 500 mW] was used as LLLT protocol for 3 successive days post-CABG. Repeated measurements of blood cell count [CBC] and cardiac damage markers [CPK, CPK-MB, LDH] attained before CABG and during the 5 days of LLLT post-operatively, taken at one and 12 hours after daily laser irradiation. In a comparison of the mean levels of the control and laser group, the variables were statistically different on 5[th] day after intervention for WBC, Neutrophil and Lymphocyte counts and WBC and lymphocyte changes. A statistically significant difference was seen in changes of CPK, CPK-mb and LDH over time P<0.001. It is concluded that low-level laser irradiation after CABG surgery could decrease cardiac cellular damage and help accelerate the repair of cardiac tissue post-operatively. This may lower post-operative disability as well as bed rest period in these patients