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Introduction: The left atrial (LA) posterior wall (LAPW) has been targeted to improve the clinical outcomes in patients with persistent atrial fibrillation (PersAF). This study aimed to investigate the feasibility, safety, and clinical implications of cryoballoon (CB) applications on the LAPW to accomplish electrical isolation (EI) of the LAPW with CB. Methods: A total of 100 patients (males, 84; mean age, 64 ± 10 years) with PersAF were enrolled. The first 50 patients underwent only pulmonary vein isolation (PVI) (PVI‐only group) and the remaining 50 patients underwent PVI and EI of the LAPW with CB (EI‐LAPW group). Results: One‐year sinus rhythm maintenance probability was significantly higher in the EI‐LAPW group than in PVI‐only group (80.0% vs 55.1%, P = 0.01). The success rate of constructing an LA roof block line (LA‐RB), bottom block line, and EI of the LAPW was 92%, 60%, and 58%, respectively. The nadir CB temperature (−45°C ± 4°C vs −39°C ± 5°C, P = 0.005) and anatomical angle of the left atrial roof (106°C ± 30°C vs 144°C ± 17°C, P < 0.001) significantly predicted the successful LA‐RB construction. The left ventricular ejection fraction was significantly higher in unsuccessful cases than in successful cases of an EI of the LAPW (64% ± 8% vs 58% ± 11%, P = 0.041). Even though the EI of the LAPW was unsuccessful, CB freezing in LAPW significantly debulked the nonscar area (≥0.1 mV) in LAPW (18.1 ± 5.6 vs 2.2 ± 3.1 cm 2, P < 0.001) and provided the equivalent 1‐year outcome of successful cases (79.3% vs 81.0%, P = 0.90). Conclusion: The combination of PVI and EI of the LAPW with CB provided better clinical outcomes than conventional PVI procedure for patients with PersAF. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies have reported the efficacy of the cryoballoon (CB)‐guided left atrial roof block line (LARB) creation in patients with persistent atrial fibrillation (AF). However, it can be technically challenging to attach the balloon to the left atrial (LA) roof due to its anatomical variations. We designed a new procedure called the "Raise‐up Technique," which may facilitate the firm adhesion of the CB to the LA roof during freezing. This study aimed to evaluate the efficacy of the Raise‐up technique in LARB creation. Methods and Results: In total, 100 consecutive patients with persistent AF who underwent CB‐LARB creation were enrolled. Fifty‐seven patients underwent LARB creation using the Raise‐up technique (Raise‐up group), and the remaining 43 did not use it (control group). The Raise‐up technique was performed as follows: An Achieve catheter was inserted as deeply as possible into the upper branch of the right superior pulmonary vein to anchor the CB. The balloon was placed below the targeted site on the LA roof and frozen. When the temperature of the CB reached approximately −10°C and the CB was easier to attach to the LA tissue, the CB was raised and pressed against the LA roof immediately by sheath advancement. Then the balloon could be in firm contact with the target site on the roof. If necessary, additional sheath advancement after sufficient freezing (−20°C to −30°C) was allowed the CB to have more firm and broad contact with the target site. LARB creation without touch‐up ablation was achieved in 54 of 57 patients (94.7%) in the Raise‐up group and 33 of 43 patients (76.7%) in the control group (p <.05). The lesion size of the LARB in the Raise‐up group was significantly larger than that in the control group (15.2 cm2 vs. 12.8 cm2, p <.05). Moreover, the width of the LARB lesion in the Raise‐up group was wider than that in the control group (32.0 mm vs. 26.6 mm, p <.05). Conclusion: The Raise‐up technique enabled the creation of seamless and thick LARB lesions with a single stroke. In addition, the CB‐LARB lesions created using the Raise‐up technique tended to be large, resulting in extensive debulking of the LA posterior wall arrhythmia substrates. In CB ablation for persistent AF, the Raise‐up technique can be considered one of the key strategies for LARB creation. [ABSTRACT FROM AUTHOR]

Introduction: Dual atrioventricular nodal non‐reentrant tachycardia (DAVNNT) is a rare and challenging‐to‐diagnose arrhythmia, without previous reports associating it with a leftward inferior extension (LIE). Methods: Diagnosis was made using adenosine triphosphate (ATP) injection during atrial pacing in a suspected DAVNNT patient. Results: Ablation of the rightward inferior extension was unsuccessful in eliminating DAVNNT; however, subsequent ablation of the LIE successfully eradicated the arrhythmia. Conclusion: This unique case, marked by the first instance of DAVNNT caused by LIE, diagnosed through ATP injection, underscores the utility of this diagnostic approach and broadens the spectrum of our understanding and management of this condition. [ABSTRACT FROM AUTHOR]

Introduction: The major limitation of the current cryoballoon (CB) system is a fixed 28 mm balloon‐size. We sought to analyze real‐world early experience with novel‐sized adjustable CB. Methods: This multicenter observational study included 140 consecutive atrial fibrillation patients (71 years, 94 men, 86 paroxysmal) who underwent pulmonary vein (PV) isolation using expandable diameter CB capable of ablation at 28 or 31 mm. Results: Out of 544 targeted PVs, 526 (96.7%) were successfully isolated by a size‐adjustable CB with a 770 [690−870] second median application dose, while the remaining 18 required touch‐up ablation. Among them, 326 (62.0%) PVs were isolated by a 31 mm balloon, and the rate was significantly higher for upper than lower PVs (73.0% vs. 45.7%, p <.0001) and highest for right superior (78.5%) and lowest for right inferior (39.9%) PVs. The biophysical parameters and time to isolation were comparable between the 28 and 31 mm balloons, however, the real‐time PV potential monitoring capability was significantly higher for 31 mm than 28 mm balloons for the left superior PV. The esophageal temperature reached 15°C during left inferior PV ablation significantly more often with 31 mm than 28 mm balloons (43.1% vs. 18.2%, p =.008). Right phrenic nerve injury (PNI) occurred in 9 (6.4%) patients during applications (6 right superior, 2 right inferior PVs), and most occurred with a 31 mm balloon. Conclusions: Our real‐world early data demonstrated high acute efficacy and safety of the novel‐sized adjustable CB. The biophysical parameters were similar between the 28 and 31 mm balloons. No marked decrease in the incidence of PNI was observed even with 31 mm balloons. [ABSTRACT FROM AUTHOR]

Introduction: Cryoballoon ablation (CBA) of the left atrial (LA) roof in addition to a pulmonary vein isolation has been expected to improve the clinical outcomes post‐atrial fibrillation (AF) ablation. We demonstrated the characteristics and efficacy of CBA of the LA roof through our experience with a large volume of procedures. Methods: Among 1036 AF ablation procedures with CBA of the LA roof, 834 patients who underwent a de novo ablation were analyzed. Results: Complete LA roof line conduction block was obtained in 767 patients (92.0%) solely by CBA (Group A). Compared with the other patients (Group B), the mean nadir balloon temperature during CBA of the LA roof (−44.5 ± 5.6°C for Group A vs. −40.5 ± 7.5°C for Group B, p <.01) and number of cryoballoon applications during the LA roof ablation with a circular mapping catheter located in the left superior pulmonary vein (1.3 ± 0.8 for Group A vs. 1.6 ± 1.0 for Group B, p =.02) were significantly lower in Group A. A multivariate analysis revealed that those were predictors of a complete LA roof conduction block after only CBA. The 1‐year Kaplan–Meier atrial arrhythmia free rate estimates were 80.6% for Group A and 59.0% for Group B (p <.01). Conclusion: Complete LA roof line conduction block could be obtained with a cryoballoon without touch‐up ablation in most cases. The LA roof CBA with a circular mapping catheter located in the right superior pulmonary vein was preferable to obtaining complete LA roof conduction block, which was important with regard to the clinical outcomes. [ABSTRACT FROM AUTHOR]

Backgrounds: Catheter ablation for non‐paroxysmal atrial fibrillation (non‐PAF) remains challenging and more effective strategy has been required to reduce postoperative arrhythmia recurrences. This study aims to investigate the efficacy and safety of a novel extensive ablation strategy for non‐PAF, that is based on a combination of cryoballoon (CBA), radiofrequency (RFA), and Marshall‐vein ethanol ablations (EA‐VOM). Methods: The study was a single‐center, retrospective observational study. We enrolled 171 consecutive patients who underwent de‐novo catheter ablation for non‐PAF under conscious sedation with a novel extensive ablation strategy that included CBA for pulmonary vein isolation (PVI) and left atrial roof ablation (LARA), RFA for mitral isthmus (MI) ablation, superior vena cava isolation, and other linear ablations and EA‐VOM. Recurrence of atrial arrhythmias over 1 year, procedure outcomes, and procedure‐related complications were investigated. Results: A total of 139 (81.3%) patients remained in sinus rhythm during 1‐year follow‐up. Of the 139 patients, 51 patients (29.8%) received antiarrhythmic drugs. The mean procedure time was 204 ± 45 min. PVI and LARA ablation by CBA and MI block by RFA and EA‐VOM were completed in 171 (100%) and 166 (97.1%) patients, respectively. No serious procedure‐related complications were observed except for one case of delayed pericardial effusion. Conclusion: Approximately 80% of the study patients were AF‐free during 1‐year follow‐up period after a single procedure based on the novel extensive ablation strategy combining CBA, RFA, and EA‐VOM. This strategy for non‐PAF may be preferred in terms of maintenance of sinus rhythm, safety even in high‐risk patients, and relatively short procedure time. [ABSTRACT FROM AUTHOR]

Introduction: Adenosine triphosphate (ATP) sensitive atrial tachycardia (AT) has been treated by radiofrequency catheter ablation. Cryofreezing energy has emerged as a novel energy source for catheter ablation. The aim of this study was to investigate the efficacy and safety of cryofreezing ablation for ATP‐sensitive AT. Methods and Results: A total of six patients with ATP‐sensitive ATs were included in this study. A single atrial extrastimulation was able to initiate and terminate these ATs in all six patients. The electrophysiological findings satisfied the diagnostic criteria of ATP‐sensitive AT. The ablation catheter was located at the earliest activation site of atrial excitation during the AT, and cryofreezing energy was delivered through a cryoablation catheter to perform cryomapping at temperature of −30 or −80°C. When cryomapping successfully terminated the ATs, cryoablation at a temperature of −80°C was subsequently performed. The earliest atrial activation during AT was recorded at the Koch's triangle area associated with a distinct intra‐atrial activation sequence from that recorded during ventricular pacing. Cryoablation was performed at successful cryomapping sites and resulted in the complete elimination of the AT in all six patients without affecting the bidirectional atrioventricular (AV) nodal conduction. Conclusion: Cryofreezing energy was safe and effective in treating ATP‐sensitive ATs even in patients with its origins located in the vicinity of the AV node. [ABSTRACT FROM AUTHOR]

Background: The cryoballoon (CB) can be utilized for extra pulmonary vein (PV) ablation such as for a left atrial (LA) posterior wall (LAPW) isolation. However, scrutiny of the esophageal injuries during the LAPW isolation has never been performed. We sought to thoroughly investigate the esophageal lesions (ELs) and gastric hypomotility (GH) caused by an LAPW isolation using a CB. Methods: A total of 101 persistent atrial fibrillation patients who underwent an LAPW isolation using a CB were enrolled. The CB was applied on the roof and bottom area of the LAPW after a PV isolation. The luminal esophageal temperature (LET) was monitored by a thermistor probe during the CB applications. When the LET reached 15°C, the freezing application was prematurely interrupted. Esophagogastroscopy was performed on the next day following the ablation. Results: All PVs were successfully isolated in all patients. A successful LAPW isolation solely with CB ablation was performed in 72 (71.3%) patients. Cryofreezing applications were prematurely interrupted due to low LETs in 49 (48.5%) patients predominantly during the LA bottom line ablation. ELs and GH were observed in 11 (10.9%) and 16 patients (15.8%), respectively. The nadir LET tended to be lower in patients with ELs and GH than in those without (ELs: 14.8 ± 4.5°C vs 17.4 ± 6.0°C, P = 0.17; GH: 15.5 ± 4.5°C vs 17.5 ± 6.1°C, P = 0.23, respectively). Conclusions: Esophageal complications such as ELs and GH occur during the LAPW isolation with a CB. There was no reliable predictor of those adverse events. [ABSTRACT FROM AUTHOR]