Incidence of Atrial Fibrosis in Non-Valvular Atrial Fibrillation Patients and its Impact on Recurrence after Pulmonary Vein Antrum Isolation

Abstract

SUMMARY A lthough pulmonary vein antrum isolation eliminates the triggers for atrial fibrillation development, a significant number of patients have developed recurrence during follow up. Thus, left atrium fibrosis as an important contributor of atrial substrate may play a role in recurrence and maintenance of atrial fibrillation episodes after catheter ablation. This study investigated the presence of atrial fibrosis in patients with lone paroxysmal atrial fibrillation and its impact on recurrence after pulmonary vein antrum isolation. Twenty eight patients referred to the Cardiology department at Ain Shams University Hospitals for first-time pulmonary vein antrum isolation for the treatment of symptomatic paroxysmal lone atrial fibrillation. A detailed electroanatomical voltage maps were done in the right and left atria before pulmonary vein antrum isolation. Low-voltage zones (atrial fibrosis) were defined as areas with bipolar peak-to-peak voltage amplitudes of < 0.5 mV and covering > 5% of the total atrial body surface area. Follow up for recurrence was done for 6 month duration after the procedure. Atrial fibrillation burden prior to the procedure was significantly higher in the recurrence group as compared to no recurrence group with P-value 0.002 and the presence of left atrium fibrosis was significantly higher in the recurrence group as compared to non recurrence group with P-value 0.024. The only significant predictors of atrial fibrillation recurrence were the presence of left atrium fibrosis P=0.046 and atrial fibrillation burden prior to the procedure P=0.023. The only significant predictor of the presence of left atrium fibrosis was atrial fibrillation burden prior to the procedure P=0.031. There were no significant differences between the recurrence and non recurrence groups regarding age, gender, BMI, AF duration, response to medical treatment, ejection fraction, left atrium anteroposterior diameter, lateral mitral annulus E’ wave, diastolic function and the presence of right atrium fibrosis (P>0.05 for all).