Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation Using a Circular Multipolar Ablation Catheter: Safety and Efficacy Using Low-Power Settings.

INTRODUCTION: The circular irrigated decapolar nMARQ ablation catheter designed for treating atrial fibrillation (AF) has recently been recalled following two deaths due to esoatrial fistula. Injury to the esophagus has been previously reported in up to 50% of patients using 20-25 W unipolar radiofrequency (RF) energy. Low power of 15 W has been proposed to prevent this complication, but the efficacy of this strategy to avoid AF recurrence is unknown.

METHODS AND RESULTS: Consecutive patients with drug-refractory, symptomatic AF were included. Under electroanatomical navigation, the nMARQ catheter was used to isolate all PVs by applying 15 W of unipolar RF simultaneously from up to 10 poles during 40 seconds. Multiple applications were used for each vein, until isolation was achieved. Follow-up was performed after a 2-month blanking period. A total of 50 patients (37 males, age 58 ± 10 years) were included. All PVs were acutely isolated without requiring touch-up by conventional ablation catheters. Pericardial effusion occurred in two patients, of whom one required periocardiocentesis. Right phrenic nerve palsy occurred in another patient, which partially resolved. There were no cases of esophageal fistula or stroke. After a follow-up of 15 ± 4 months, AF recurred in 27/50 (54%) patients.

CONCLUSION: The recurrence rate of AF with 15 W unipolar applications is high. Despite use of low power, complications such as pericardial effusion and phrenic nerve palsy may occur.