Cryoballoon ablation of atrial fibrillation in patients with atypical right pulmonary vein anatomy.

BACKGROUND: Cryoballoon ablation is widely used for pulmonary vein isolation in patients with atrial fibrillation. There are no data regarding the clinical efficacy of cryoballoon ablation in patients with atypical right pulmonary vein anatomy. AIM: We aimed to evaluate the impact of right pulmonary vein anatomy on the safety and efficacy of cryoballoon ablation. METHODS: Patients referred for cryoballoon ablation of paroxysmal atrial fibrillation were enrolled prospectively. Left atrial computed tomography was performed before cryoballoon ablation to determine whether the right pulmonary vein anatomy was "normal" or "atypical". For patients with atypical anatomy, cryoballoon ablation was only performed for right superior and right inferior pulmonary veins, neglecting accessory pulmonary veins. RESULTS: Overall, 303 patients were included: 254 (83.8%) with normal and 49 (16.2%) with atypical right pulmonary vein anatomy. First-freeze isolation for right superior and right inferior pulmonary veins occurred in 44 (89.8%) and 37 (75.5%) patients with atypical pulmonary vein anatomy, and in 218 (85.8%) and 217 (85.4%) patients with typical pulmonary vein anatomy, respectively (P not significant). Phrenic nerve palsies were only observed in patients with normal anatomy (0 vs. 26 [8.6%]; P=0.039). Mid-term survival free from atrial arrhythmia was similar, regardless of right pulmonary vein anatomy. CONCLUSIONS: A significant proportion of patients have atypical right pulmonary vein anatomy. Procedural characteristics, acute pulmonary vein isolation success and mid-term procedural efficacy were similar, regardless of right pulmonary vein anatomy. In addition to left-side pulmonary vein isolation, cryoballoon ablation of right superior and right inferior pulmonary veins only, neglecting accessory pulmonary veins, is sufficient to obtain acute right-side pulmonary vein isolation and mid-term sinus rhythm maintenance in patients with atypical anatomy.

The challenging right inferior pulmonary vein: A systematic approach for successful cryoballoon ablation.

BACKGROUND: Pulmonary vein isolation (PVI) using cryoballoon ablation is widely used for rhythm control in patients with paroxysmal atrial fibrillation. This technique has a steep learning curve, and PVI can be achieved quickly in most patients. However, the right inferior pulmonary vein (RIPV) is often challenging to occlude and isolate. AIM: We aimed to analyse the efficacy of RIPV ablation using a systematic approach. METHODS: Consecutive patients referred for cryoballoon ablation of paroxysmal atrial fibrillation were enrolled prospectively. A systematic approach was used for RIPV cryoablation. The primary endpoint was acute RIPV isolation during initial freeze. RESULTS: A total of 214 patients were included. RIPV isolation during initial freeze occurred in 179 patients (82.2%). Real-time PVI could be observed in 72 patients (33.6%), whereas cryoballoon stability required pushing the Achieve™ catheter inside the RIPVs in the remaining patients. The rate of unsuccessful or aborted first freeze as a result of insufficient minimal temperature was significantly higher in patients with real-time pulmonary vein potential recording (16.7% vs. 6.3%; P=0.031). To overcome this issue and obtain both stability and real-time PVI, a dedicated "whip technique" was developed. Twelve patients (5.6%) required a redo ablation; only two of these had a reconnected RIPV. CONCLUSIONS: A systematic approach to RIPV cryoablation can lead to a high rate of first freeze application. Operators should not struggle to visualize pulmonary vein potentials before ablation, as this may decrease cryoapplication efficacy. Thus, stability should be preferred over real-time PVI for RIPV ablation. Both stability and real-time PVI can be obtained using a "whip technique".