Cardiac troponin T does not increase after electrical cardioversion for atrial fibrillation or atrial flutter.
OBJECTIVE
To determine whether cardiac troponin T increases after electrical cardioversion in patients with atrial fibrillation or atrial flutter.


METHODS
Serum creatine kinase (CK), creatine kinase-MB (CKMB), and cardiac troponin T were measured before, 24 hours, and 48 hours after cardioversion in 15 patients with atrial fibrillation or atrial flutter.


RESULTS
12 of the 15 patients (80%) were successfully cardioverted to sinus rhythm. The median number of shocks was three (range one to six), the median cumulative energy 710 J (50 to 1430 J), and the median peak energy 300 J (50 to 360 J). Total CK increased from a baseline median concentration of 92 (45 to 259) to 1324 (96 to 6660) U/l at 24 hours and 1529 (120 to 4774) U/l at 48 hours after cardioversion. There was a small increase in CKMB but the ratio of CKMB to CK did not increase. There was no increase in cardiac troponin T in any patient.


CONCLUSIONS
Following electrical cardioversion of atrial fibrillation or atrial flutter, cardiac troponin T remains unchanged despite a large rise in total CK, indicating that the CK is derived from skeletal muscle and that myocardial injury does not occur. If cardiac troponin T is increased after cardioversion for atrial arrhythmias then other causes of myocardial damage should be sought.
Greaves
K
K
Department of Cardiology, St Bartholomew's Hospital, West Smithfield, London, UK.
Crake
T
T
D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood / Q000628:therapy*; D001282:Atrial Flutter / Q000097:blood / Q000628:therapy*; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D004554:Electric Countershock; D005260:Female; D006801:Humans; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D018709:Statistics, Nonparametric; D013997:Time Factors; D020107:Troponin T / Q000097:blood*
D015415:Biomarkers; D007527:Isoenzymes; D020107:Troponin T; D003402:Creatine Kinase