The aim of this study was to determine whether paroxysmal atrial fibrillation (PAF) and/or restoration to sinus rhythm with
electric or pharmacologic cardioversion induce modifications to the coagulation system. Thirty-five patients with PAF undergoing
either electric (n = 11) or pharmacologic (n = 24) cardioversion were studied. Fibrinopeptide A and D-dimer blood
samples were taken immediately before and after cardioversion at different intervals. When compared with the control
group (n = 70), the precardioversion fibrinopeptide A plasma values were significantly elevated (11.8 vs 2.5 ng/mL). Fibrinopeptide
A plasma values were significantly reduced 5 minutes after cardioversion (11.8 vs 5.3 ng/mL) and remained stable
throughout the follow-up sequential measurements. D-dimer plasma values were significantly increased (measured at 12
hours and at day 7) in patients who underwent electrical cardioversions only. A positive correlation (R2 = 0.76) was found
between the energy delivered for cardioversion to sinus rhythm and D-dimer plasma values on day 7. In patients with PAF,
levels of fibrinopeptide A, an indicator of coagulation activation, are elevated and soon reduced by the restoration of sinus
rhythm. Electric, but not pharmacologic, cardioversion induces an early activation of the fibrinolytic system.
