[Myocardial damage following cardioversion]

In order to ascertain myocardial damage secondary to D.C. cardioversion, we studied 20 patients from the National Institute of Cardiology Ignacio Chávez, in whom an elective electric countershock was applied because of rythm abnormalities. We studied the patients before and after the procedure with E.C.G., enzyme levels (SGOT, LDH, CKMB), and myocardial scintigraphy to detect possible myocardial lesions. Only in two patients the CKMB rose to a significant level. The ECG changes were significant in 40 per cent, and myocardial scintigraphy was positive in a diffuse pattern in 50 per cent of the cases. The interpretation of the three studies as a whole, showed an absolute lack of correlation between them. We conclude that DC countershock is a safe and innocuous procedure, to which no myocardial damage can be attributed, if it is used within the normal limits of clinic.