[Levels of fatty acid binding protein before and after direct current cardioversion of atrial fibrillation or flutter in patients without acute coronary syndrome].
It is not known whether FABP suggested as an early marker of myocardial necrosis increases after direct current cardioversion (DCC). Moreover there are no data on FABP levels in patients with atrial fibrillation (AF) and flutter.


OBJECTIVE
To find out whether DCC induces acute changes of FABP levels in patients with AF or flutter without acute coronary syndrome.


METHODS
Serum FABP and troponin I (TnI) were measured in 63 pts treated with DCC (monophasic shocks) because of AF (n=45, 71.4%) or atrial flutter (n=18, 28.6%). Initial energy was 50J for atrial flutter and 200J for AF. Median total energy was 200J, max 660J. Blood was sampled before DCC and in 30, 60 min, 3, 6 h after first shock. TnI and FABP were measured with single-step sandwich method ("Hytest" Finland). Upper limit of normal range (ULN) for TnI was 0.4 ng/ml (recommended by manufacturer). Serum FABP was measured in healthy volunteers and 95th percentile was used as ULN (4.67 ng/ml).


RESULTS
Most pts (n=40, 63.5%) had baseline FABP > ULN (median for all pts--5.55 ng/ml). In 11 pts (17.4%) baseline FABP was > 2 ULN. No relationship was found between baseline FABP and age, sex, duration of arrhythmia, concomitant ECG changes, and presence of overt coronary heart disease or clinical signs of heart failure. Median FABP level increased after DCC (p for trend 0.00014). FABP levels after DCC correlated with total delivered energy. Delivery of > or = 2 shocks compared with 1 shock was associated with higher FABP (median 60 min--9.65 and 5.24 ng/ml, p=0.009; 3 h--12.41 and 5.84 ng/ml, p=0.01, respectively). Median TnI levels were below ULN at each study point. After DCC TnI did not exceed ULN in 61 pts and remained unchanged in 2 pts with baseline TnI above ULN.


CONCLUSIONS
Unexpectedly most pts with AF and atrial flutter had elevated FABP at baseline. After DCC FABP increased in proportion with total delivered energy. Elevations of FABP levels were not associated with rapid increases of TnI so skeletal muscle damage can be a likely cause of elevated FABP. AF, atrial flutter and DCC for these arrhythmias should be considered as sources of false positive results when FABP is used for diagnosis of acute myocardial infarction.
Mazovets
O L
OL
Katrukha
A G
AG
Trifonov
I R
IR
Bereznikova
A V
AV
Deev
A D
AD
Gratsianskiĭ
N A
NA
D000208:Acute Disease; D001281:Atrial Fibrillation / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D003327:Coronary Disease; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation*; D004562:Electrocardiography; D050556:Fatty Acid-Binding Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D009336:Necrosis / Q000473:pathology; D012720:Severity of Illness Index; D013997:Time Factors; D014336:Troponin / Q000097:blood*
D050556:Fatty Acid-Binding Proteins; D014336:Troponin