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Aim A novel third-generation cryoballoon (CB3) to perform pulmonary vein isolation (PVI) has recently been released, featuring a shortened distal balloon tip when compared with the second-generation (CB2), possibly allowing for enhanced intra-ablation pulmonary vein (PV) signal mapping. We aimed to investigate procedural efficacy and safety of the CB3 as compared to the CB2. Methods and results We studied 472 consecutive patients who underwent CB-PVI for paroxysmal or persistent atrial fibrillation (CB3: 49 patients; CB2: 423 patients). Detailed procedural data and in-hospital complications were registered in a prospective database. Complete PVI using the CB only was achieved in 98% of patients in each group. Single-freeze PVI was observed in 84/88% (CB2/CB3, P = n.s.) of the PVs. Time-to-PVI (TPVI) was 49 ± 32 (CB2) and 45 ± 27 s (CB3) ( P = n.s.). Time-to-PVI determination rate was higher in the CB3 group (89.5 vs. 82.6%, P = 0.016). Signal noise due to ice formation on mapping electrodes occurred after 70 ± 46 s using CB3 and did not interfere with TPVI determination. Exchange of the spiral mapping catheter with a guide wire was more frequently required in the CB3 group (8.2 vs. 0.7% patients, P < 0.001). Balloon dislodgement during hockey stick manoeuvres occurred in 6.1% patients of the CB3 group only ( P = 0.001). Complication rates were not different between the groups. Conclusion The CB3 offers a higher TPVI determination rate, facilitating dosing schemes based on TPVI, with equally high single-freeze efficacy compared with the CB2. The shortened distal tip of the CB3 requires adaptation of standard catheter manoeuvers to avoid balloon dislodgement.

Cryoballoon ablation has been demonstrated to allow safe and effective isolation of pulmonary veins (PV) for the treatment of paroxysmal atrial fibrillation. Recently, the second-generation cryoballoon device has been developed (Arctic Front Advance, Medtronic CryoCath LP) with improved cooling capabilities by increasing the number of refrigerant injectors, resulting in homogeneous cooling of the balloon surface. In contrast, the first-generation balloon is characterized by a cooling zone concentrated on the equator of the balloon with less cooling around the frontal nose. This limitation is hypothesized to result in incomplete lesion formation in the myocardium contacting this area, specifically the inferior circumference of the inferior PVs.1 The nonhomogeneous cooling of the first-generation device may also explain a relative long time to left atrium-PV block recorded …

Two versus One Repeat Freeze–Thaw Cycle(s). Background: Repeated freezing (bonus applications) during cryoballoon pulmonary vein isolation (PVI) has been suggested to improve lesion durability. However, the long-term clinical effects of repeated freezing have not been investigated. Methods and Results: A total of 51 patients (pts) with paroxysmal atrial fibrillation (AF) underwent PVI using the single big (28 mm) cryoballoon technique. One (27 pts, group I) or 2 bonus applications (24 pts, group II) were performed at all PVs subsequent to PVI. Clinical follow-up consisted of continuous rhythm monitoring by an implantable cardiac monitor (ICM, 24 pts) and serial 7-day Holter-ECG recording (7DH, 27 pts). The primary endpoint was defined as recurrent AF or atrial tachycardia. Acute PVI of all PVs was obtained in 50/51 pts (98%). The median (Q1;Q3) follow-up duration in this study was 384 (213;638) days. The primary endpoint occurred in 48% (group I, 15 pts ICM, 12 pts 7DH) and 46% (group II, 9 pts ICM, 15 pts 7DH), P = 0.84. Procedure- and fluoroscopy-time for group I versus group II was 193 ± 56 minutes versus 207 ± 27 and 33 ± 13 minutes versus 34 ± 11 minutes, respectively. Right phrenic nerve palsy (PNP) occurred in 3 pts (all group II, time to resolution: 128 ± 112 days). In 2 of these pts, PNP occurred during the second bonus application. Conclusion: Application of 2 when compared to 1 freeze–thaw cycle(s) following cryoballoon PVI did not result in improved clinical success but was associated with a higher complication rate. (J Cardiovasc Electrophysiol, Vol. 23, pp. 814-819, August 2012)

Background The optimal energy setting for endoscopic pulmonary vein (PV) isolation (PVI) has not yet been determined. Objective To assess the influence of varying energy settings on the efficacy and safety of endoscopic PVI. Methods In the current prospective study, 30 patients with paroxysmal atrial fibrillation were consented for PVI using the endoscopic ablation system. Ablation was performed by using 5.5 and 7.0 W (group A), 7.0 and 8.5 W (group B), and 8.5 and 10.0 W (group C) along the posterior and anterior portion of each PV, respectively. Intraluminal esophageal temperature was measured via a temperature probe with a cutoff of 38.5°C. Endoscopy was performed 2 days postablation. Results After the completion of the initial circular lesion set, acute PVI was achieved in 25 of the 36 (69%) PVs in group A, in 29 of the 40 (73%) PVs in group B, and in 36 of the 40 (90%) PVs in group C, respectively. The rate of acute PVI was significantly higher in group C than in group A ( P = .025) and group B ( P = .045); there was no difference when comparing group A and group B ( P = .77). Esophageal thermal lesions were detected in 0 of the 10 patients in group A, in 1 of the 10 (10%) patients in group B, and in 1 of the 10 (10%) patients in group C. Mean procedure and fluoroscopy times were 219 ±42 and 30 ± 10, 239 ± 61 and 38 ± 14, and 207 ± 31 and 28 ± 8 minutes for group A, B, and C, respectively. Conclusions The use of higher energy settings increases the efficacy of acute endoscopic ablation system–based PVI without comprising safety. Further investigation is mandatory before final conclusions can be drawn.

This editorial refers to ‘Pulmonary vein ostium shape and orientation as possible predictors of occlusion in patients with drug-refractory paroxysmal atrial fibrillation undergoing cryoballoon ablation’ by A. Sorgente et al. , on page 205. Cryoballoon pulmonary vein isolation (CB-PVI) is attractive for many electrophysiologists because the device allows in principle to isolate the pulmonary veins (PVs) with a single application and a short learning curve.1,2 In order to achieve an effective lesion, the cryoballoon must be positioned with good circumferential tissue contact at the PV ostium, usually ascertained by the absence of contrast media run-off from the balloon tip into the left atrium during PV angiography.1–3 This means that the operator has to face a wide variety of left atrial and PV anatomies with a pre-shaped device that cannot be adapted to a patient's individual anatomy. Device selection is further limited in that the use of the smaller of the two available cryoballoon dimensions (23 and 28 mm) may impose an increased risk of right phrenic nerve …

Cryoballoon pulmonary vein isolation (PVI) currently requires a long cryoballoon application (CBA) time of 240 to 300 seconds, thus repeated ineffective CBA prolongs procedure duration. We hypothesized that cryoballoon temperature (CBT) may be used to discriminate between effective and ineffective CBA during freezing.This study sought to evaluate CBT as a predictor of CBA efficiency.Sixty-six patients with atrial fibrillation underwent PVI using the single big (28 mm) cryoballoon technique. CBT was continuously recorded. After each CBA (300 seconds), a Lasso catheter (Biosense Webster, Inc., Diamond Bar, California) was placed into the target pulmonary vein (PV) to determine whether electrical PV disconnection was present. Only the first CBA at each PV was analyzed to avoid cumulative effects.The CBT was lower during CBA at superior compared with inferior PVs. When individual CBAs were grouped according to successful/failed PVI, CBT was lower for those CBAs that resulted in successful PVI at all time points analyzed. To test the performance of CBT to predict failed CBA, receiver-operator curves were constructed. A minimal CBT of ≥ -42°C/ -39°C (superior/inferior PVs) predicted failed PVI with 73%/92% specificity (area under the curve 0.82/0.81); positive predictive value (PPV) 74%/74%. A minimal CBT of-51°C was invariably associated with PVI. After 120 seconds of freezing, a CBT of ≥ -36°C/ -33°C (superior/inferior PVs) predicted failed PVI with 97%/95% specificity (area under the curve 0.82/0.76); PPV 82%/80%.Balloon temperature predicts successful target PVI during cryoablation and may serve in the early identification of noneffective balloon applications.

Pulmonary vein isolation using a cryoballoon has evolved into a relatively simple alternative for point-by-point radiofrequency ablation because this technology theoretically allows for PV isolation with a single application. Recent clinical studies indicate a high efficacy rate of the procedure; however, the incidence of the most common complication-phrenic nerve palsy (PNP)-has been reported in up to 11.2% of cases. Based on the present data, PNP is mainly associated with the use of the smaller 23 mm balloon. Very recently, it became evident that cryoballoon ablation may be associated with PV stenosis. Thus, the use of cryoballoon technology needs to be combined with a strategy aiming for maximal patient safety. The "single big (28 mm) cryoballoon technique" is a straightforward single-device strategy to deploy cryothermal lesions proximal to the PV ostium at the antrum level, thereby reducing the risk of collateral damage. Using this technique the endpoint of complete PV isolation was achieved in 97% of patients in our laboratory. PNP was observed in 4.4% of patients and resolved within 12 months in the majority of cases. In the future, development of an even bigger (32 mm) cryoballoon may further increase procedural safety by reducing the risk of PNP or PV stenosis.

Esophageal Effects of Single Big Cryoballoon PVI. Introduction: Reversible esophageal thermal lesions after cryoballoon pulmonary vein isolation (CB-PVI) have been reported when using variable balloon sizes. The aim of this study was to investigate (1) the incidence of esophageal thermal lesions, and (2) esophageal temperature changes associated with CB-PVI using the single big cryoballoon technique. Methods and Results: Thirty-eight patients with atrial fibrillation underwent successful CB-PVI using only the 28 mm cryoballoon. Luminal esophageal temperature (LET) was continuously monitored by 3 thermocouples. Fluoroscopic distance from cryoballoon to esophagus probe was retrospectively evaluated in RAO 30° and LAO 40° projections. All patients underwent postprocedural esophageal endoscopy. Average minimal LET was lower during freezing at inferior PVs, when compared to superior PVs: 35.4 ± 0.9 (range: 32.6 to 37.4; RSPV); 31.5 ± 7.5 (2.5 to 37.6; RIPV); 32.9 ± 5.2 (8.5 to 36.5; LSPV); and 30.3 ± 8.4°C (−6 to 36.7°C; LIPV); P = 0.001. We found steep temperature gradients over distance (1) from the cryoballoon center (LETs < 10°C confined to a distance of < 15 mm in both RAO 30° and LAO 40° projections), and (2) along the esophagus long axis, underscoring the need for multiple measurement sites. None of the patients showed esophageal thermal lesions at endoscopy after 3 ± 1 (range 1–7) days. No AEF occurred during a follow-up of 125 ± 78 days. Conclusion: In a cohort of AF patients treated by the single big cryoballoon technique, CB-PVI was not associated with thermal esophageal lesions. (J Cardiovasc Electrophysiol, Vol. 21, pp. 869-874, August 2010)

Background— Radiofrequency current ablation of atrial fibrillation (AF) requires high technical skills to achieve optimal catheter stability and is associated with an individually high x-ray exposure to both the patient and the operator. To facilitate catheter navigation and to reduce the operator’s x-ray burden, remote navigation (RN) systems have been developed. Considerations for navigation of a novel remote robotic navigation system in pulmonary vein isolation (PVI) procedures are reported. Methods and Results— In 65 patients with drug-refractory AF (43 paroxysmal, 22 persistent), complete circumferential PVI was performed using RN in conjunction with different electroanatomic mapping systems. Acute complete PVI using exclusively RN was achieved in 95%. The procedure time was 195�40 minutes. The operator’s x-ray exposure time was reduced by 6�4 minutes (35%) using RN. In 7 of 14 patients with persistent AF, conversion to sinus rhythm was achieved by radiofrequency current ablation. During a median follow-up period of 239 days (range, 184 to 314 days), 47 of 65 patients (73%) remained free of any documented atrial tachyarrhythmia recurrences after a single procedure. The relative proportion of patients remaining free of AF was 76% and 68% for paroxysmal and persistent AF, respectively. Conclusions— PVI using the novel RN system can be performed safely and effectively. One third of the operator’s fluoroscopy exposure time might be saved using RN. However, the questions of whether the overall fluoroscopy exposure is reduced by RN and whether RN improves PVI procedures needs to be assessed during a comparative trial between man and machine.

Background Pulmonary vein isolation using the cryoballoon technique (CB-PVI) has evolved into a simple and safe alternative for point-by-point radiofrequency ablation. Systematic analysis of conduction recovery occurring after CB-PVI and causing recurrent atrial fibrillation has not yet been performed. Objective The purpose of this study was to analyze conduction recovery after PVI using the single big (28-mm) cryoballoon technique. Methods Twenty-six patients with recurrent atrial tachyarrhythmia after previous CB-PVI underwent repeat ablation. Pulmonary vein (PV) reisolation was performed by antral irrigated radiofrequency ablation using electroanatomic mapping. For analysis of the location of conduction gaps, the ipsilateral LA–PV junction was divided into six equally distributed segments. Results PV reconduction frequently occurred into multiple (>2) PVs (54% patients). Conduction gaps could be abolished by single point ablation in 63% (lateral) and 41% (septal) of patients or by incomplete circular lesions in the remaining patients. A significantly higher number of patients exhibited conduction recovery at inferior segments (85% lateral, 77% septal) compared with superior segments (42% lateral, 31% septal). Furthermore, the ridge between PV ostia and left atrial appendage (LAA) was highly associated with reconduction into lateral PVs (81% of patients). Retrospective analysis of the initial CB-PVI-procedure revealed lower freezing temperatures at superior than inferior PVs as well as sharp catheter angulations with loss of central cryoballoon alignment to reach inferior PVs. Conclusion Conduction recovery after CB-PVI occurs at a high incidence at inferior sites around ipsilateral PV ostia and the LAA–PV ridge. Modifications of the technique to ensure optimal balloon–tissue contact at predilection sites may improve long-term success rates.

Pulmonary Vein Conduction During Cryoballoon Ablation. 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. (J Cardiovasc Electrophysiol, Vol. pp. 1-8). ispartof: Journal of Cardiovascular Electrophysiology vol:20 issue:11 pages:1203-1210 ispartof: location:United States status: published