title: 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)>150J was associated with significant elevation of CK and myoglobin levels after cardioversion (1.52+/-3.81 microkat/l and 187+/-433 microg/l), while CE<150J was not (-0.04+/-0.34 and 4+/-11, p<0.05). In BP group, CE>150J was associated with significant but smaller CK elevation (0.27+/-1.09 microkat/l, p<0.05) and comparable myoglobin elevation (80.7+/-21.4 microg/l, p<0.05). CE>150J 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>150J 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.
authors.affiliation: 2nd Department of Internal Cardiovascular Medicine, General Teaching Hospital, U Nemocnice 2, 128 08 Prague 2, Czech Republic. romanskulec@yahoo.com
authors.forename: Roman
authors.initials: R
authors.lastname: Skulec
authors.forename: Jan
authors.initials: J
authors.lastname: Belohlavek
authors.forename: Tomas
authors.initials: T
authors.lastname: Kovarnik
authors.forename: Jirí
authors.initials: J
authors.lastname: Kolar
authors.forename: Jana
authors.initials: J
authors.lastname: Gandalovicova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Dytrych
authors.forename: Ales
authors.initials: A
authors.lastname: Linhart
authors.forename: Michael
authors.initials: M
authors.lastname: Aschermann
mesh_terms: D001281:Atrial Fibrillation / Q000097:blood / Q000378:metabolism / Q000628:therapy; D001282:Atrial Flutter / Q000097:blood / Q000378:metabolism / Q000628:therapy; D015415:Biomarkers / Q000097:blood*; D004554:Electric Countershock / Q000379:methods*; D006801:Humans; D013612:Tachycardia, Ectopic Atrial / Q000097:blood / Q000378:metabolism / Q000628:therapy; D013617:Tachycardia, Supraventricular / Q000097:blood* / Q000378:metabolism / Q000628:therapy*
chemical_list: D015415:Biomarkers