Background: We evaluated the efficacy of Cox-maze IV procedure using bipolar irrigated radiofrequency ablation and cryothermy in chronic atrial fibrillation associated with valvular heart disease.
Material and methods: From November 2005 to June 2009, ninety four patients have undergone valvular heart surgery with Cox-maze IV procedure. Preoperative duration of atrial fibrillation was 7.6±6.5 years and follow-up duration was 22.7±12.3 months.
Results: There were two (2.1%) postoperative deaths not related to maze procedure. Two cerebrovascular accidents, five low cardiac output syndromes and two permanent pacemaker implantations have occurred after surgery. Preoperative ejection fraction on echocardiography was 55.3±8.1% and ejection fraction of postoperative six month was 54.7±6.5%. Left atrial size of preoperative and postoperative were 61.5±11.6 mm and 53.1±8.4 mm at each. Freedom from atrial fibrillation rate at postoperative six-month was 80.7% and the cases of recurrence of atrial fibrillation after six months were three (3.3%). Risk factors for failure or recurrence of maze procedure were old age (p=.010) and preoperative moderate or severe tricuspid regurgitation (p=.033).
Conclusion: The Cox-maze IV procedure using RFBP2 and cryothermy is quite safe and freedom from atrial fibrillation at postoperative 6 month was 82.5%. Risk factors for failure or recurrence of atrial fibrillation after Cox-maze IV were old age and preoperative over moderate tricuspid regurgitation.
Keywords: Ablation; Arrhythmia; Arrhythmia surgery; Valve disease.