KARDIOCHIRURGIA DOROSŁYCH
Analysis of factors affecting the efficacy of radio frequency ablation in patients operated on mitral valve disease

Introduction : Atrial fibrillation is the most common supra­ventricular arrhythmia. This arrhythmia increases the risk of stroke, heart failure and death. Atrial fibrillation often coexists with mitral valve diseases. Currently, the most commonly used method in surgical treatment of AF is modification of the Cox maze III procedure using the radio frequency current to make transmular scars within the left atrium.

Aim : The aim of this study was to assess the early and late effectiveness of endocardial radiofrequency ablation in patients operated on mitral valve disease. We also analyzed factors which may have influence on effectiveness of ablation.

Material and methods : The study group included 86 patients operated at the Department of Cardiac Surgery Medical University of Lublin from 2005 until 2010. The analyzed factors that may have influence on effectiveness of ablation were age, sex, nature of AF, duration of permanent AF, left atrial dimension, left ventricular ejection fraction, stable sinus rhythm during hospitalization and the nature of the mitral valve defects.

Results: The overall effectiveness of ablation in the analy­zed group ranged from 68.2% at discharge to 77% after

6 months. The duration of atrial fibrillation and maintaining a stable sinus rhythm in the postoperative period were factors that had statistically significant impact on early and late effectiveness. The dimension of the left atrium and the nature of the AF were not statistically significant factors, despite the trend, which indicated a better efficacy of abla­tion in patients with LA < 5 cm and paroxysmal AF. We also

observed a trend suggesting that the efficacy of the ablation

decreased in patients with the ischemic mitral regur­gita­tion. Analysis did not show statistical signifi­cance. Factors that had no effect on early and late results were gender, age and the left ventricular ejection fraction.

Conclusions : Endocardial RF ablation is an effective and safe treatment for AF in patients who undergo mitral valve defects operation.