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Introduction: The novel cryoballoon with 28 mm or 31 mm adjustable diameters, aims to achieve a wide antral pulmonary vein isolation (PVI). However, the distribution of antral lesions and their variations based on left atrial (LA) remodeling require further clarification. Methods: We evaluated 22 patients (67 [59.5–74.8] years, 19 males) who underwent PVI of atrial fibrillation (AF) (13 paroxysmal AF [PAF] and 9 non‐PAF) using size‐adjustable cryoballoons. LA electro‐anatomical mapping was performed post‐PVI with three‐dimensional mapping systems. We assessed the shapes of the LA and pulmonary veins (PVs) and the distribution of isolated areas (IAs), comparing the results between PAF and non‐PAF patients. Results: In the left PVs (LPVs), the distance between the PV orifice and IA edge (PVos‐IA) was larger on the roof and posterior segments (~15 mm) but relatively smaller on the anterior segment near the PV ridge (<10 mm). For the right PVs (RPVs), it was more extensive in the posterior segment (10–15 mm). Comparing PAF and non‐PAF, there were no significant differences in the PVos‐IA except for the right posterior‐carina segment, antrum IA (LPVs: 5.9 ± 1.6 vs. 5.8 ± 0.8 cm², p =.81; RPVs: 4.8 ± 2.3 vs. 4.8 ± 1.2 cm², p =.81), distances between the right and left IAs on the LA posterior wall (LAPW), and un‐isolated LAPW area (9.0 ± 4.9 vs. 9.9 ± 2.5 cm², p =.62). No individual PVIs were observed in either group. Two patients exhibited overlapping IAs on the roof, and one patient who underwent 31 mm balloon applications for all PVs exhibited an LAPW isolation. Conclusion: The size‐adjustable cryoballoon achieved a wide antral PVI even in non‐PAF patients. [ABSTRACT FROM AUTHOR]

Introduction: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low‐voltage‐bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB. Materials and Methods: Three‐dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut‐off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio. Results: Twenty‐seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut‐off of 0.3−1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001). Conclusion: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure. [ABSTRACT FROM AUTHOR]

An editorial is presented on Potential advantages of the KODEX‐EPD system as the fourth 3D mapping system for atrial fibrillation ablation. Topics include cardiac arrest in a randomized fashion could not definitely reveal the advantage of catheter ablation compared with medical therapy among patients with AF; and distinct dielectric properties of biological tissue by measuring voltages between body surface sensors and the catheters.

Objective: To evaluate the role of ultrahigh‐density mapping for conduction isthmus (CI) characterization in adult congenital heart disease (ACHD). Background: Catheter ablation remains suboptimal for ACHD with atypical intra‐atrial reentrant tachycardias (IART) that can be challenging to define using existing mapping technology. Methods: An ultrahigh‐density mapping system was selectively employed over a 1‐year period for procedures involving noncavotricuspid isthmus‐dependent‐IART. A global activation histogram (GAH) was assessed for the ability to predict ablation targets. Procedural characteristics were compared to a group of matched controls. Results: Twenty patients (mean age 43 ± 15, 70% male) underwent 20 procedures targeting 34 tachycardias during the study period. Diagnoses included single ventricle (8), tetralogy of Fallot (2), left heart obstruction (3), Ebstein's anomaly (2) atrial septal defect (2), Mustard operation (2), and Rasteilli operation (1). Prior catheter ablation/Maze operation had been performed in 12 (60%). The median time per map was 21 minutes (interquartile range [IQR], 16‐32), representing 14 834 points per map (IQR 9499‐43 191; P < .001 vs controls). Review of GAH maps showed lower trough values were associated with more favorable IART CI characteristics (P ≤ =.001 for all). Acute success was achieved in 19/20 (95%) procedures, with tachycardia termination during the first lesion in eight cases (P = .02 vs controls). There was one recurrence during 0.6 years follow‐up. Conclusions: Ultrahigh‐density mapping supplemented with the GAH tool was effective for CI identification in a cohort of complex ACHD patients. Catheter ablation was more efficient compared to controls, suggesting precise CI characterization using this technology. [ABSTRACT FROM AUTHOR]

Two female patients undergoing left atrial radiofrequency catheter ablation developed Tako-tsubo cardiomyopathy. This reversible form of left ventricular dysfunction is known to occur under conditions associated with marked sympathetic nervous activation. Radiofrequency catheter ablation in the left atrium can damage autonomic ganglionated plexi, leading to vagal withdrawal, thus resulting in enhanced sympathetic tone. Tako-tsubo cardiomyopathy has not been previously described following radiofrequency catheter ablation. [ABSTRACT FROM AUTHOR]

Introduction: Precise localization of target sites for radiofrequency catheter ablation (RFCA) of arrhythmias is hampered by the relative inaccuracy of X-ray localization procedures. This study evaluated the efficacy of a three-dimensional (3D) real-time position management system in guiding RECA procedures in patients. Methods and Results: Patients (n = 30, age 59 ± 20 years) referred for ablation of either atrial flutter (n = 10), ventricular tachycardia (n = 15), or accessory pathways (n = 5) were studied. The real-time position management system uses ultrasound ranging techniques to track the position of an ablation catheter relative to two multitransducer reference catheters, positioned in the right atrium or coronary sinus and the right ventricle. Each catheter contains three or four ultrasound transducers. The distance between the transducer(s) Is determined by calculating the time necessary for an ultrasound pulse to reach other transducers, assuming the speed of sound in blood is 1,550 m/sec. The proximal His bundle was marked at the beginning and the end of the procedure as an electrical landmark to verify reproducibility. After identification of target sites, the position of each lesion created with the ablation catheter was marked. Successful ablation was achieved in 94% of the patients. The distance between the location of the proximal His bundle as marked at the beginning and at the end of the procedure was 2.0 ± 1.2 mm (range 1.5 to 3.5). conclusion: The new 3D real-time position management system facilitated RFCA procedures as it allowed accurate and reproducible 3D tracking of the mapping and ablation catheter. [ABSTRACT FROM AUTHOR]