Myocardial damage after D.C. countershock: myoglobin and CK-MB radioimmunoassay evaluation.

After D.C. countershock to terminate cardiac arrhythmias, in 3 out of 8 patients studied, an increase in both plasma myoglobin (Mb) and CK-MB (assessed by radioimmunoassay) was found. In 2 patients there was an increase of only plasma Mb and in 1 an increase of only CK-MB. In 2 cases no increase of either parameters was found. It is suggested that the radioimmunoassay technique for measuring Mb and CK-MB might have a greater reliability than other techniques for the detection of myocardial damage.