Serum cardiac markers response to biphasic and monophasic electrical cardioversion for supraventricular tachyarrhythmia-a randomised study

Abstract

Background: Electrical cardioversion in patients with various types of supraventricular tachyarrhythmia (SVT) may induce serum cardiac markers elevation. Only a few studies have evaluated the impact of the type of shock waveform on electrical myocardial injury. The aim of our study was to compare the response of serum cardiac markers to biphasic and monophasic cardioversion for SVT. Methods: One hundred and forty one patients with various SVTs referred for electrical cardioversion were randomised to monophasic (MP) or biphasic (BP) cardioversion. Serum levels of creatine kinase (CK), MB fraction of CK (CK-MB), myoglobin and troponin I were analysed before cardioversion and 254 ± 58 min after the procedure. Results: Average age of the patients was 67.9 ± 11.3 years, 71 underwent BP and 70 MP cardioversion. In MP group, cumulative energy (CE) > 150 J was associated with significant elevation of CK and myoglobin levels after cardioversion (1.52 ± 3.81 μkat/l and 187 ± 433 μg/l), while CE < 150 J was not (-0.04 ± 0.34 and 4 ± 11, p < 0.05). In BP group, CE > 150 J was associated with significant but smaller CK elevation (0.27 ± 1.09 μkat/l, p < 0.05) and comparable myoglobin elevation (80.7 ± 21.4 μg/l, p < 0.05). CE > 150 J was the only independent positive predictor for CK and myoglobin elevation in both groups. No significant changes in CK-MB and Troponin I levels after cardioversion were identified. Conclusions: According to our study, electrical cardioversion for SVTs is not associated with biochemical signs of myocardial injury. Application of CE > 150 J can be followed by CK and myoglobin elevation most likely due to skeletal muscle damage. This reaction is more pronounced in MP than in BP cardioversion. © 2006 Elsevier Ireland Ltd. All rights reserved.