Electrophysiologic study for ventricular arrhythmia: effect on total and myocardial-specific creatine kinase activity

To determine the potential for myocardial injury during electrophysiologic study for ventricular arrhythmia, total creatine kinase and creatine kinase B-subunit enzyme activity were serially measured after the procedure in 24 patients. During electrophysiologic study 14 of the 24 patients had sustained ventricular tachycardia or fibrillation, 4 patients had nonsustained ventricular tachycardia, and 6 patients had no ventricular arrhythmia induced. Cardioversion was necessary because of hemodynamic collapse in 9 of the 14 patients with sustained ventricular tachycardia or ventricular fibrillation. Coronary heart disease was present in 14 of the 24 patients, in 9 of the 14 with sustained ventricular tachycardia or ventricular fibrillation, and in 7 of the 9 patients requiring cardioversion. Total creatine kinase was modestly elevated (greater than twice baseline or greater than normal, or both) 24 hours after electrophysiologic study in 10 (42%) of the patients. Electrophysiologic study with or without the induction of ventricular tachycardia or ventricular fibrillation was not associated with increased creatine kinase B-subunit activity even in patients with coronary heart disease.