Termination of long-lasting persistent versus short-lasting persistent and paroxysmal atrial fibrillation by ablation.

BACKGROUND: Left atrial (LA) structures for the maintenance of different atrial fibrillation (AF) forms are not uniform. The incidence, electrophysiological patterns, and LA sites of sinus rhythm (SR) restoration during ablation of different AF forms were evaluated.

METHODS: One hundred patients with long-lasting persistent AF were retrospectively compared to 35 patients with short-lasting persistent AF and 59 patients with a sustained episode of paroxysmal AF. All patients underwent a first ablation using a stepwise ablation approach with the endpoint of SR restoration by ablation.

RESULTS: SR was restored in 38%, 83%, and 97% of patients with long-lasting persistent, short-lasting persistent, and paroxysmal AF, respectively (P <0.001 for long-lasting persistent vs paroxysmal AF; P = 0.02 for long-lasting persistent vs short-lasting persistent AF). When modes and sites of SR restoration were evaluated among the patients with long-lasting persistent, short-lasting persistent, and paroxysmal AF, SR was restored via conversion into LA tachycardia in 79%, 52%, and 4% of patients (P <0.001 for long-lasting persistent vs paroxysmal AF); by the pulmonary vein encircling in 8%, 24%, and 93% patients (P <0.001 for long-lasting persistent vs paroxysmal AF); and by ablation at the LA anterior wall or inside the coronary sinus in 66%, 45%, and 2% patients (P <0.001 for long-lasting persistent and paroxysmal AF). During the 31 +/- 14 month follow-up since the first ablation, of the 50 patients with long-term SR maintenance (38 patients free of class I or III antiarrhythmic drugs), SR was restored by ablation in 29 (58%) patients versus nine (18%) patients out of 50 patients with unsuccessful clinical outcome (P = 0.009).

CONCLUSION: Ablation of long-lasting persistent AF was characterized by more frequent failure to restore SR, and predominant conversion into LA tachycardia prior to SR restoration, and SR restoration by ablation outside the LA posterior wall. SR restoration by ablation was associated with better clinical outcome in these patients.