Efficacy of Three Different Ablative Procedures to Treat Atrial Fibrillation in Patients with Valvular Heart Disease: A Randomised Trial

K.E.M. Hospital, Mumbai, India.
Heart, Lung and Circulation (Impact Factor: 1.44). 07/2008; 17(3):232-40. DOI: 10.1016/j.hlc.2007.10.003
Source: PubMed


Various modifications have been proposed to the original Cox's Maze procedure due to concerns about the long bypass and cross clamp times. The efficacy of these procedures has been studied and reported. We conducted a randomised prospective study to compare three procedures, differing in extent, of ablation in patients in atrial fibrillation who were undergoing surgery for rheumatic valvular heart disease. These procedures utilised radiofrequency in the bipolar mode. The extent of ablation was (1) biatrial (replication of the Cox Maze) (2) left atrial portion of the Cox Maze and (3) pulmonary vein isolation along with a control group (the No Maze group). Conversion rate to sinus rhythm was studied over a mid-term follow-up period.
A total of 160 patients were studied with 40 patients in each group. Antiarrhythmic drugs were not used in the three months preceding surgery and for seven days postoperatively. The patients underwent surgery for their valve disease along with the ablative procedure as per randomisation using radiofrequency microbipolar coagulation and cryoablation. They were followed up and were evaluated for symptomatic improvement, rhythm with ECG documentation and 2D echocardiography.
Follow-up was available for 133 patients. Mid-term results showed that sinus rhythm was restored in 62.5% patients of Biatrial Maze group and 57.5% in the Left Atrial Maze. In the Pulmonary Vein Isolation Maze group, 67.5% patients converted to NSR whereas in the No Maze group only 20% patients were in sinus rhythm (p value for all the groups was 0.001 when compared to the No Maze group). The incidence of other arrhythmias was not significant and there were no other major complications. All the patients in sinus rhythm at follow-up were in NYHA functional class I-II and showed good effort tolerance.
Results achieved with the three ablative procedures are comparable. Therefore lesser procedures viz. Left Atrial Maze and the Pulmonary Vein Isolation Maze procedures must be studied further with the additional use of antiarrhythmic drugs.

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Available from: Vasudev Baburaya Pai, Jul 13, 2014
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    • "There is no doubt that bipolar radiofrequency (RF) ablation is better than unipolar RF ablation to cure the atrial fibrillation (AF) because of the full transmurality achieved almost exclusively by the bipolar RF. I have discussed this matter previously [2] [3]. The presumed basis of successful AF ablation is production of myocardial lesions that block the propagation of AF wave fronts from a rapidly firing triggering source or modification of the arrhythmogenic substrate responsible for re-entry. "
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