Objective: Endocardial ablation of the left atrial posterior wall has been used to treat atrial fibrillation. Aim of the study was to evaluate its efficacy looking for the ablation pattern allowing a fast execution with limited interference on atrial contractility. Moreover a statistical analysis to identify predictors of long-term sinus rhythm recovery has been provided.
Methods: From April 1998 to May 2002, 95 patients with permanent (mean duration 65 months) or persistent (33%) atrial fibrillation have undergone three different ablation patterns, only 1 patient being affected by lone atrial fibrillation. Mean antero-posterior left atrial diameter was 76.2 mm. The prospective study collected information regarding variables related to patients' demographics, disease's characteristics and type of surgical ablation employed. Dependent variables were presence of sinus rhythm either at discharge and at 6 months. A logistic regression analysis was used to estimate the association between the collected variables and sinus rhythm restoration.
Results: In-hospital and late mortality rate were 3.2 and 6.3% respectively. At discharge 67 patients (72.8%) were in sinus rhythm while at a mean follow-up of 3 years, 81.4% of 86 surviving patients are in sinus rhythm. Major adverse events rate including cardiac reoperation, pace-maker implantation and cerebrovascular accident were 8.5, 6.3 and 4.2%, respectively. Pre-operative atrial fibrillation duration, left atrial dimension and type of mitral disease did not show any correlation with long term success while the lesion pattern and the rhythm at discharge were significant predictive factors. Survival is significantly higher in patients who converted to sinus rhythm at discharge (P=0.014) with respect to those who remained in atrial fibrillation.
Conclusions: Permanent and persistent atrial fibrillation associated to a major cardiac disease can be safely treated with a linear ablation of the left atrial posterior wall. Satisfactory results in terms of rhythm restoration may be achieved regardless of the duration of the arrhythmia and its effects on atrial diameter. Any effort should be prompted to discharge patients in sinus rhythm. Life expectancy is longer if sinus rhythm is restored.