An Evaluation Of The Safety And Efficiency Of Ibutilide For Conversion Of Persistent Atrial Fibrillation During Radiofrequency Ablation

Background：Atrial fibrillation or atrial flutter could be successfully terminatedwith ibutilide by intravenous injection. However, whether ibutilide could be safe andeffective to patients with persist atrial fibrillation during ablation remained unknown.Objective: The aim of this study was to investigate the efficiency and safety ofibutilide for cardioversion of persistent atrial fibrillation during radiofrequency ablationand the factors affected conversion.Methods:18patients including16males and2females with persistent atrialfibrillation were enrolled in this study. All patients underwent circumferentialpulmonary vein ablation guided by a Carto three-dimensional mapping system. Inaddition, linear ablation at the roof of left atrium and isthmus of mitral valves andcomplex fractionated atrial electrogram (CAFE) ablation were performed.1mgibutilide were given to all patients who remained atrial fibrillation or atrial flutter afterablation within10minutes or reaching an endpoint by intravenous injection. Definitionof endpoint: sinus rhythm (SR) or adverse reactions such as ventricular tachycardiaCardioversion rate within30minutes and adverse reactions within4hours wereobserved. All patients were divided into either conversion group or non-conversiongroup according to whether AF was converted to sinus rhythm within30minutes afteributilide administration.Results: There were no significant differences in gender, age, body mass index，left atrium and left ventricular function between the two groups.11patients (61.11%)converted to SR after ibutilide injection. The average conversion timewas13.80±7.64mins., patients in the non-conversion group had a significant larger left atrium scar area ratio12.4.±11.03%than conversion group5.12±3.83%(p<0.05).Ibutilide significantly prolonged the average atrial cycle length0.17±0.29ms vs0.24±0.40s,(p<0.001) compared with that before injection. The QT intervalsignificantly prolonged than that before injection thirty minutes later of ibutilideinjection0.39±0.21s vs0.51±0.08s，(p <0.05). No serious arrhythmias or other adversereactions were found.Conclusions: Ibutilide is highly effective and safe. There were not seriousarrhythmias or other adverse reactions after ibutilide injection. The left atrium scar arearatio affected conversion rate significantly.