Comparison of the clinical outcome after pulmonary vein isolation based on the appearance of adenosine-induced dormant pulmonary vein conduction.

BACKGROUND: The elimination of transient pulmonary vein (PV) reconduction (dormant PV conduction) revealed by adenosine in addition to PV isolation reduced the atrial fibrillation (AF) recurrence after catheter ablation. The dormant PV conduction is induced in approximately half of the AF patients that undergo PV isolation. The present study compared the clinical outcome of AF ablation in patients whose dormant PV conduction was eliminated by additional radiofrequency applications with the outcome in patients without dormant conduction. METHODS: A total of 233 consecutive patients (206 male, 54.2 +/- 10.1 years) that underwent AF ablation were included in the present study. Dormant PV conduction was induced by the administration of adenosine triphosphate after PV isolation and was eliminated by supplemental radiofrequency application. All patients were followed up for >12 months (mean 903 days) after the first ablation. RESULTS: Following PV isolation, dormant PV conduction was induced in 139 (59.7%) of 233 patients and was successfully eliminated in 98% (223/228) of those in the first ablation procedure. After the first procedure, 63.9% (149/233) of patients were free from AF recurrence events. The success rates of a single or final AF ablation in patients with the appearance of the dormant PV conduction were similar to those of patients without dormant conduction (P = .69 and P = .69, respectively). CONCLUSIONS: Dormant PV conduction was induced in over half of the patients with AF. After the elimination of adenosine triphosphate-induced reconnection, the clinical outcome of patients with the dormant PV conduction was equivalent to that of patients without conduction.

Prospective randomized comparison of a steerable versus a non-steerable sheath for typical atrial flutter ablation.

AIMS: Although cavotricuspid isthmus (CTI) ablation can cure typical atrial flutter (AFL), it might be difficult to achieve a bidirectional conduction block in the isthmus in some patients. We investigated the usefulness of a steerable sheath for CTI ablation in patients with typical AFL or atrial fibrillation. METHODS AND RESULTS: A total of 40 consecutive patients (36 males; mean age 55.2 +/- 10.0 years) undergoing CTI ablation were randomized to one of the following two groups: group S (using a steerable long sheath) or group NS (using a non-steerable long sheath). Ablation was performed using an 8 mm tip catheter. The anatomy of the CTI was evaluated by a dual-source computed tomography scan prior to the procedure. The procedural endpoint was the achievement of a bidirectional isthmus conduction block. Bidirectional block in the CTI was achieved in all patients with 485.3 +/- 416.4 s of radiofrequency (RF) application. The CTI anatomy, including the length, depth, and morphology, was similar between the two groups. The duration and total amount of RF energy delivery were significantly shorter and smaller in group S than in group NS (310 +/- 193 vs. 661 +/- 504 s, P = 0.006, and 12,197 +/- 7306 vs. 26,906 +/- 21,238 J, P = 0.006, respectively). CONCLUSION: The use of a steerable sheath reduced the time and amount of energy needed to achieve a bidirectional conduction block in the CTI. For patients in whom the establishment of a conduction block is difficult, a steerable sheath should be considered as a therapeutic option for typical AFL ablation.