Use of cardiac troponin T rapid assay in the diagnosis of a myocardial injury secondary to electrical cardioversion

Background and hypothesis: This study was carried out to determine whether cardiac troponin T test in rapid assay gives positive results in patients previously submitted to cardioversion or electrical defibrillation. Methods: Forty patients with supraventricular tachyarrhythmias lasting no more than 2 days were treated with electrical cardioversion. The total creatine phosphokinase (CPK)-MB isoenzyme and troponin T in rapid assay were measured at baseline and at 6, 12, and 24 h thereafter. Results: Total CPK baseline levels were normal in all cases; within 4 h, the serum CPK levels increased by 98%, at 6 h by 111.5%, at 12 h by 168%, and at 24 h by 225% (p > 0.01). The CPK-MB isoenzyme showed no percentage increase of total CPK higher than 5%, measured at 6, 12, and 24 h after the shock, independent of the number of attempts of cardioversion. The troponin T test was also negative in all cases at baseline and at 6, 12, and 24 h after cardioversion. Conclusion: We conclude that the absence of elevations in CPK-MB levels and cardiac troponin T levels matched clinical and electrocardiographic results showing absence of myocardial damage after electrical cardioversion.