A medico-legal approach to the myocardial changes caused by transthoracic direct current countershock

The myocardial damage caused by transthoracic direct current countershock was evaluated serologically and histologically. Countershock energy of between 12 and 240 watt-second (ws) discharge was given to rabbits. Total creatine kinase (total CK) and creatine kinase-MB isozyme (CK-MB) activities in plasma were increased after the countershock, with peak values averaging 5690 IU/L (total CK) and 35 IU/L (CK-MB) within 6 h, whereas the CK-MB activity of a rabbit subjected to countershock in the femoral region was within normal range of less than 3 IU/L. Histologically, epicardial alteration was found in electrode-shaped areas which confined to the superficial epicardium in all rabbits. The heart from rabbits that died within a few minutes after countershock showed epicardial alteration in right and left ventricles, and subendocardial alteration with focal hemorrhage was evident in the left ventricle. Subendocardial necrosis and interstitial edema were also revealed in the left ventricle 72 h after countershock. These myocardial damages appeared in the transthoracic pathway between the electrodes. Thus, we conclude that the myocardial damage caused by countershock is distinguishable from heart disease in terms of the characteristic areas and measuring CK levels.