Myocardial damage after exposure to high-voltage electrical current has been reported to result in a serious and often life-threatening situation. However, because the diagnosis of myocardial injury based on ECG and creatinine kinase MB (CK-MB) is not reliable, the changes in myocardial function are not identified yet. The purpose of this study was to investigate the alterations in the left ventricular function using two-dimensional speckle tracking imaging. A total of 11 male patients with high-voltage (>22,900 V) electrical injuries were prospectively evaluated. Serial echocardiogram was obtained on days 1, 3, and 7. Serum CK-MB and troponin I levels were drawn on admission and for the first 24 hours. All parameters were compared to age- and sex- and body mass index-matched healthy control. There were no significant differences in stroke volume index, fractional shortening, ejection fraction, and peak strain (S) when compared to controls. In contrast to peak strain, peak systolic mitral annular velocity (Sa) and peak systolic strain rate (SR) were significantly increased and maintained throughout follow up in patient group (Table). No significant correlations were found between the increase of troponin I or CK-MB levels and all parameters of systolic function. These results demonstrate that the LV myocardial change after high-voltage electrical injury is related to an increase of LV systolic function rather than myocardial depression, and indicate changes of troponin I or CK-MB levels are not associated with myocardial damage.