Impact of Systematic Isolation of Superior Vena Cava in Addition to Pulmonary Vein Antrum Isolation on the Outcome of Paroxysmal, Persistent, and Permanent Atrial Fibrillation Ablation: Results from a Randomized Study

Impact of the Systematic Isolation of the Superior Vena Cava.   Background: Pulmonary veins (PVs) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation (AF). However, additional non-PV triggers, arising from different areas, have been reported as well. One of the most common non-PV sites described is the superior vena cava.
Aims: The purpose of the study was to investigate the impact resulting from the systematic isolation of the superior vena cava (SVCI) in addition to pulmonary vein antrum isolation (PVAI) on the outcome of paroxysmal, persistent, and permanent AF ablation.
Methods: A total of 320 consecutive patients who had been referred to our center in order to undergo a first attempt of AF ablation were randomized into 2 groups. Group I (160 patients) underwent PVAI only; Group II (160 patients) underwent PVAI and SVCI.
Results: AF was paroxysmal in 134 (46%), persistent in 75 (23%), and permanent in 111 (31%) of said patients. SVCI was performed on 134 of the 160 patients (84%) in Group II. SVC isolation was not performed on the remaining 26 patients either because of phrenic nerve capture or the lack of SVC potentials. Comparison of the outcome data between the 2 groups, after a follow-up of 12 months, revealed a significant difference in total procedural success solely with patients manifesting paroxysmal atrial fibrillation (56/73 [77%] Group I vs. 55/61 [90%] Group II; P = 0.04; OR 2.78).
Conclusions: In our study, the strategy of the empiric SVCI in addition to PVAI has improved the outcome of AF ablation solely in patients manifesting paroxysmal AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1–5, January 2010)     

心房颤动上腔静脉节段性电隔离方法及安全性评估

目的:分析心房颤动(房颤)上腔静脉节段性电隔离的具体手术方法,并评估其安全性.方法:入选2017年11月至2018年9月期间我院阵发性房颤患者50例,患者常规进行肺静脉隔离后,继续行上腔静脉隔离.消融前进行上腔静脉造影,显示上腔静脉与右心房解剖关系,并在CARTO系统运用PentaRay电极导管进行上腔静脉及右心房三维...     

Cryoballoon Versus Radiofrequency for Pulmonary Vein Re‐Isolation After a Failed Initial Ablation Procedure in Patients with Paroxysmal Atrial Fibrillation

Cryoballoon versus Radiofrequency Ablation . Aim: Catheter ablation of paroxysmal atrial fibrillation (PAF) is associated with an important risk of early and late recurrence, necessitating repeat ablation procedures. The aim of this prospective randomized patient‐blind study was to compare the efficacy and safety of cryoballoon (Cryo) versus radiofrequency (RF) ablation of PAF after failed initial RF ablation procedure. Methods: Patients with a history of symptomatic PAF after a previous failed first RF ablation procedure were eligible for this study. Patients were randomized to Cryo or RF redo ablation. The primary endpoint of the study was recurrence of atrial tachyarrhythmia, including AF and left atrial flutter/tachycardia, after a second ablation procedure at 1 year of follow‐up. All patients were implanted with a cardiac monitor (Reveal XT, Medtronic) to continuously track the cardiac rhythm. Patients with an AF burden (AF%) ≤ 0.5% were considered AF‐free (Responders), while those with an AF% > 0.5% were classified as patients with AF recurrences (non‐Responders). Results: Eighty patients with AF recurrences after a first RF pulmonary vein isolation (PVI) were randomized to Cryo (N = 40) or to RF (N = 40). Electrical potentials were recorded in 77 mapped PVs (1.9 ± 0.8 per patient) in Cryo Group and 72 PVs (1.7 ± 0.8 per patient) in RF Group (P = 0.62), all of which were targeted. In Cryo group, 68 (88%) of the 77 PVs were re‐isolated using only Cryo technique; the remaining 9 PVs were re‐isolated using RF. In RF group, all 72 PVs were successfully re‐isolated (P = 0.003 vs Cryo). By intention‐to‐treat, 23 (58%) RF patients were AF‐free vs 17 (43%) Cryo patients on no antiarrhythmic drugs at 1 year (P = 0.06). Three patients had temporary phrenic nerve paralysis in the Cryo group; the RF group had no complications. Of the 29 patients who had only Cryo PVI without any RF ablation, 11 (38%) were AF‐free vs 20 (59%) of the 34 patients who had RF only (P = 0.021). Conclusion: When patients require a redo pulmonary vein isolation ablation procedure for recurrent PAF, RF appears to be the preferred energy source relative to Cryo. (J Cardiovasc Electrophysiol, Vol. 24, pp. 274‐279, March 2013)     

Cryoballoon Pulmonary Vein Isolation with Real-Time Recordings from the Pulmonary Veins

Introduction: Cryoballoon (CB) ablation represents a novel technology for pulmonary vein isolation (PVI). We investigated feasibility and safety of CB-PVI, utilizing a novel spiral catheter (SC), thereby obtaining real-time PV potential registration.
Methods: Following double transseptal puncture, a Lasso catheter (Biosense Webster, Diamond Bar, CA, USA) and the 28 mm CB were positioned within the left atrium. A novel SC (Promap, ProRhythm Inc., Ronkonkoma, NY, USA) was inserted through the lumen of the CB allowing PV signal registration during treatment. Time to PV conduction block was analyzed. If no stable balloon position was obtained, the SC was exchanged for a regular guide wire and PV conduction was assessed after treatment by Lasso catheter.
Results: In 18 patients, 39 of 72 PVs (54%) were successfully isolated using the SC. The remaining 33 PVs were isolated switching to the regular guide wire. Time to PV conduction block was significantly shorter in PVs in which sustained PVI was achieved as compared to PVs in which PV conduction recovered within 30 minutes (33 ± 21 seconds vs 99 ± 65 seconds). In 40 PVs, time to PV conduction block was not obtained because of: (1) PVI not being achieved during initial treatment; (2) a distal position of the SC; or (3) isolation with regular guide wire. No procedural complications occurred.
Conclusion: Visualization of real-time PV conduction during CB PVI is safe, feasible, and allows accurate timing of PVI onset in a subset of PVs. Time to PV conduction block predicts sustained PVI. However, mechanical properties of the SC need to be improved to further simplify CB PVI.     

Cryoballoon Pulmonary Vein Isolation Supported by Intracardiac Echocardiography: Integration of a Nonfluoroscopic Imaging Technique in Atrial Fibrillation Ablation

Intracardiac Echo Supported Cryoballoon Ablation . Introduction: Cryoballoon ablation has been adopted for pulmonary vein (PV) isolation (PVI) in many centers. Complete occlusion of PV by an adequately sized balloon is crucial for effectiveness of cryoenergy delivery. The aim of this study was to evaluate intracardiac echocardiography (ICE) as an alternative imaging technique compared to angiographic imaging in cryoballoon PVI. Methods and Results: A total of 75 PVs were treated in 22 patients (61 ± 13 years, 17 male) undergoing PV cryoballoon ablation for drug refractory paroxysmal atrial fibrillation. Decision for an adequate balloon size was based on diameters of the PV antra assessed by ICE and PV angiography. Per PV 2.4 ± 0.4 cryoenergy pulses were applied. Decision for the balloon size was similar either based upon angiography or on ICE. A single 23 or 28 mm balloon was chosen in 10 and 3 patients, respectively. Two different sized balloons were used in 9 patients. PVI was evaluated after 2 cryoenergy applications. Total occlusion of the PV confirmed by ICE color flow Doppler (CFD) during ablation predicted successful PVI in 70 of 75 (93%) and unsuccessful PVI in 8 of 8 (100%). PV flow registered by pulsed wave Doppler at the PV ostium pre‐ and postablation was 0.48 ± 0.10 and 0.51 ± 0.12 m/s, respectively (n.s.). PVI was finally confirmed by entrance block in all PVs. No procedural complications occurred. Conclusions: ICE is a feasible novel imaging technique in cryoballoon ablation procedures. It allows decision for adequate balloon size, exact balloon placement, prediction of acute ablation success, and excludes acute narrowing of PV ostia. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1325‐1330, December 2010)     

Mitral Isthmus Block in a Case of Persistent Left Superior Vena Cava

Mitral Isthmus Block in Superior Vena Cava . Persistent left superior vena cava (LSVC), an uncommon venous anomaly, could be an arrhythmogenic source of atrial fibrillation. Multiple electrical connections were reported between the LSVC and the left atrium, which may negatively impact the achievement of conduction block during linear ablation of left mitral isthmus. We describe a case with perimitral atrial flutter (AFL) in a patient with isolated LSVC. AFL was successfully treated and complete perimitral conduction block was achieved following a lengthy epicardial radiofrequency application. (J Cardiovasc Electrophysiol, Vol. 22, pp. 343‐345, March 2011)