Background: There is little recent information regarding outcome and its determinants following cardioversion (CV) for atrial fibrillation (AF) or flutter. This study aims to help improve prediction of cardiac rhythm outcome following CV for AF.
Methods: Cardiac rhythm at 6 weeks and 12 months was documented following elective (EC; n=496) or immediate (IC; n=52) cardioversion for AF or atrial flutter in a single referral centre.
Results: 65 and 58% of IC patients remained in sinus rhythm (SR) 6 weeks and 1 year after CV (respectively) compared with 43% and 30% in EC patients (P<0.001). Independent positive predictors of SR 6 weeks after cardioversion included amiodarone therapy (OR 2.04 [1.28-3.33], P<0.01) and atrial flutter (OR 1.85 [1.09-3.13], P<0.05). Negative predictors included the need for >1 shock to achieve SR (OR 1.61 [1.12-2.37], P=0.011) and arrhythmia duration, (OR 0.96 [0.95-0.97], P<0.001). At 1 year, amiodarone, duration of arrhythmia and the need for >1 shock remained independent predictors of rhythm.
Conclusions: The number of shocks required to achieve SR is a newly demonstrated independent predictor of rhythm outcome after elective CV.