Feasibility of mitral isthmus and left atrial roof linear lesions using an 8 mm tip cryoablation catheter.

BACKGROUND: Left atrial linear lesions are part of the ablation strategy for persistent atrial fibrillation. Radiofrequency (RF) energy is the standard energy modality. Pulmonary vein (PV) balloon cryoablation has similar success rates to RF energy but is unsuitable for linear lesions. This study assessed the feasibility and safety of left atrial linear lesions using an 8 mm tip cryoablation catheter. METHODS AND RESULTS: Consecutive patients undergoing left atrial ablation procedures for paroxysmal or persistent atrial fibrillation were studied. An 8 mm tip focal cryoablation catheter was used to create mitral isthmus and left atrial roof linear lesions and compared to a matched cohort undergoing RF ablation. A total of 21 patients (54 ± 11 years, 14 male), 15 undergoing de novo procedures using a dual console technique (simultaneous focal catheter and cryoballoon PV ablation) and 6 redo procedures (single console and focal catheter) were studied. Mitral isthmus ablation was successful in 19/21 (91%) with a mean total ablation time of 32.5 ± 2.9 minutes. Roof line ablation was successful in 18/19 with a mean ablation time of 15.6 ± 6.0 minutes. Success rates were similar but ablation times were longer than those in the matched RF group. Epicardial ablation in the coronary sinus was required less often with cryoablation (11/21 vs 17/21, P < 0.05). There were no complications. CONCLUSION: Left atrial linear lesions with an 8 mm tip cryoablation catheter are feasible and safe with a high acute success rate. The need for coronary sinus ablation is reduced. A dual console technique is possible. Long-term durability of linear lesions remains to be determined.