Radiofrequency Ablation of Focal Activity as a Source of Persistent Atrial Fibrillation

Aim: It has been well recognized that atrial fibrillation (AF) can originate from focal sources in the pulmonary veins and extrapulmonary veins triggers. However, the role of focal activity (FA) in maintenance of persistent AF has not been well characterized. We assessed the contribution of FA in AF persistence.

Methods and results: In 2016 year 73 consecutive patients (mean age 64,26±12,24 years, 55 male)with AF were underwent radiofrequency catheter ablation (RFA). Twenty pts had persistent AF: 9 – persistent and 11 long standing persistent AF. Foci activity was diagnosed in 8 pts (70,25±12,45 лет, 6 male) utilizing activation and pace map: local activation time assessment and entrainment mapping after fast activation mapping of the hart chambers. Four pts had RFA as a first procedure and 4 had redo. Control (non-FA) group consisted of 12 consecutive patients with persistent and long-standing persistent AF who didn’t reveal foci activity. Chest ECG found in 5 of 8 FA pts nonsustained episodes of atypical atrial flutter superimposed on typical atrial fibrillation ECG pattern in compare to 1 of 12 in non-FA group (Pc²= 0,036). Cycle length in coronary sinus catheter was prolonged in FA group (209,86±98,63 ms in FA vs 154,78±23,24 ms in non-FA group, p<0,001). In FA group in 6 patients 1 foci, in 1 patient 2, and in 1 patient 3 foci activity were diagnosed. The sinus rhythm was obtained in 62,5% pts during RFA in FA group. All the rest got sinus rhythm by direct current shock. By 27 month of follow-up period subsequent to the last procedure 50% patents remained on sinus rhythm without of antiarrhythmic drugs independently of method of sinus rhythm restoration in FA AF patients.

Conclusion: Foci activity has substantial role in maintenance of persistent AF. Radiofrequency ablation of FA sources is effective strategy for arrhythmia treatment.