Atrial fibrillation recurrence after internal cardioversion: prognostic importance of electrophysiological parameters.
OBJECTIVE
To evaluate the clinical and electrophysiological determinants of arrhythmia recurrence in patients undergoing internal atrial cardioversion for chronic atrial fibrillation (AF).


METHODS
Tertiary cardiac referral centre.


METHODS
101 consecutive patients with failed external cardioversion or AF > or = 1 year underwent internal atrial cardioversion; once stable sinus rhythm (SR) was obtained, electrophysiological study was performed in 73 patients (72%) who gave informed consent. Patients were then followed on antiarrhythmic treatment.


RESULTS
101 consecutive patients underwent internal atrial cardioversion in the period 1996-1999 with 100% conversion to SR; prophylactic antiarrhythmic treatment was flecainide (52%), amiodarone (37%), and sotalol (11%). Average follow up at first AF recurrence was 18.4 (14.4) months (range 0.1-49.8 months); persistence of SR was observed in 72/101 (72%) patients. By logistic regression, AF duration (odds ratio (OR) 1.07, 95% confidence interval (CI) 1.01 to 1.13) and a lower sinus rate at discharge on antiarrhythmic drugs (OR 0.92, 95% CI 0.85 to 0.99) were independent predictors of AF recurrence, whereas age, New York Heart Association functional class, left atrial dimensions, and left ventricular ejection fraction were not predictive of arrhythmia recurrence. When electrophysiological parameters were added to the statistical model in 73 patients, a shorter atrial effective refractoriness (OR 1.04, 95% CI 1 to 1.08) and an abnormal relation of atrial effective refractoriness to cycle length (OR 31, 95% CI 3.7 to 266) were also independent predictors of AF recurrence at follow up, beyond AF duration and heart rate at discharge.


CONCLUSIONS
Patients with failed external cardioversion or long lasting AF may benefit from internal atrial cardioversion and antiarrhythmic treatment to keep SR at long term; electrophysiological study may identify patients at the highest risk of arrhythmia recurrence. Although preservation of SR seems unlikely for AF duration > 3 years, a consistent minority of this subgroup (38%) may benefit from this approach.
Biffi
M
M
Institute of Cardiology, University of Bologna, Bologna, Italy. mbiffi@orsola-malpighi.med.unibo.it
Boriani
G
G
Bartolotti
M
M
Bacchi Reggiani
L
L
Zannoli
R
R
Branzi
A
A
D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D004554:Electric Countershock / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D004594:Electrophysiology; D005260:Female; D005424:Flecainide / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012044:Regression Analysis; D013015:Sotalol / Q000627:therapeutic use; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000188:drug therapy
D000889:Anti-Arrhythmia Agents; D013015:Sotalol; D005424:Flecainide; D000638:Amiodarone