Persistent Atrial Fibrillation Ablation Using Circular Irrigated Ablation Catheter

Introduction: Persistent atrial fibrillation (PsAF) ablation remains time consuming, even when guided by non-invasive mapping. We investigated the role of a multielectrode irrigated circular radiofrequency (RF) catheter for PsAF ablation. Methods: A circular catheter (nMARQ®, Biosense Webster, Inc) with 10 irrigated simultaneous mapping and ablation electrodes was used in 50 patients with PsAF (age 60 ± 11 years, left atrial (LA) size 21.8 ± 9.7 cm2 and atrial fibrillation (AF) maximum duration 10.6 ± 9.3 months). Ablation was guided by non-invasive mapping (ECUVETM, Cardioinsight Inc.) in 32 (64%) patients. Pulmonary vein isolation (PVI) was systematically performed. Results: After targeting additional non-PV regions including 3 ± 2 indicated by ECVUETM (1-6), AF terminated in 37 (74%) patients, into atrial tachycardia (AT) in 22 and directly into sinus rhythm (SR) in 15 patients. Thirteen patients were in SR during the procedure. PVI required 8.01 ± 5.27 minutes of RF. Eleven patients required direct current (DC) shock to terminate AF. Linear lesions were performed for AT: 14 LA roof lines, 13 mitral isthmus lines and 27 cavo tricuspid isthmus (CTI). Using total of 20.24 ± 17.25 minutes of RF. Interestingly, 5/8 roof line block, 4/5 mitral isthmus line block and 19/24 CTI line block, were blocked with circular catheter only with 5.08 ± 4.58, 3.30 ± 2.56 and 3.26 ± 2.12 minutes of RF duration, respectively. A single tip conventional ablation catheter was required to complete linear lesions and obtain the block in 3 roof lines, 1 mitral isthmus line and 5 CTI. Mean procedure duration was 3.18 ± 1.03 hours. Complications included 1 pericardia effusion managed conservatively and 1 transient ischemic attack (TIA) resolved without any neurological sequelae. One year follow up data was available in 27 (54%) patients, 18 (67%) patients were in SR and 9 (33%) patients had AF recurrence in whom 1 (3%) patient had AT recurrence. Conclusion: Circular radiofrequency ablation catheter demonstrated encouraging results for rapid, safe and effective PsAF ablation when guided by non-invasive phase mapping. The catheter can be used for linear ablations and CTI in addition to PVI, thus obviating the need for an additional ablation catheter in the majority of patients.