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A 58-year-old woman was referred for atrial flutter ablation after atrial fibrillation ablation. Linear and reinforcement mitral isthmus ablation failed to terminate the perimitral flutter. During vein of Marshall ethanol infusion (VOMEI), the flutter was terminated and followed by left atrial appendage (LAA) isolation. Voltage mapping showed that a large low voltage area was created in the superior and anterior wall of left atrium. During the waiting time, the LAA activation recovered. It would be necessary to keep in mind that VOMEI would lead to uncontrolled lesion of left atrium., (© 2024 Wiley Periodicals LLC.)

Competing Interests: Funding Support and Author Disclosures This study was supported by the National Natural Science Foundation of China (No. 81970273, 82000312, 82000375), the Clinical Research Plan of Shenkang Hospital Development Center of Shanghai (No. SHDC2020CR4009, SHDC2020CR6012), the Shanghai Pujiang Program (21PJD057), and the Clinical Research Plan of Shanghai Municipal Health Commission (No. 202040461). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.

A 23-year-old woman with palpitations for 9 years was referred for catheter ablation. ECG showed an irregular narrow complex tachycardia with alternating and gradually changing QRS morphologies after alternating and changing RR intervals, with a clear pattern of 2 alternating QRS complexes. An electrophysiology study was performed and confirmed that the mechanism of tachycardia was an automatic left-side His-Purkinje system (HPS) ventricular tachycardia. The gradually changing type-2 QRS complexes was the conduction delayed in the left anterior fascicle due to the short RR interval or the short left-side HH interval. Nine months after the index electrophysiology study, the patient encounter a progressive of heart failure with increased heart rate to 130-150 bpm during rest. Radiofrequency ablation was performed at the upper-septum for eliminating the tachycardia and resulted in complete atrioventricular block. A permanent pacemaker with left bundle branch pacing was implanted. Twelve months after the ablation, the enlarged heart shrink to normal with normal left ventricular ejection fraction. In conclusion, careful interpretation of the ECG can identify the sinus P waves followed by irregular narrow complexes, thus avoiding misdiagnosis and unnecessary treatment. Unifocal HPS tachycardia could present with alternating and gradually changing narrow QRS complexes tachycardia and lead to tachycardia cardiomyopathy. Electrophysiology study and catheter ablation were useful for the diagnosis and treatment of HPS tachycardia but with high risk of atrioventricular block. However, successfully elimination the tachycardia would resolve and reverse the enlarged heart and deteriorative heart function., (© 2021 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Background: Ablation index (AI), a novel lesion quality marker, includes contact force, time, and power of radiofrequency (RF) application, but not regional variation in wall thickness within the wide antral catheter ablation (WACA) circle. This study explored the relationships among AI target value, atrial wall thickness, and gap formation within the WACA circle in patients with paroxysmal atrial fibrillation (PAF)., Methods: We evaluated 102 consecutive patients (mean age, 65 ± 9 years) with PAF who underwent AI-guided WACA for ipsilateral pulmonary vein isolation (PVI). Each WACA circle was subdivided into eight segments, and overall 7143 RF applications were delivered, including 125 gaps in PVI ablation lines. For each RF tag within the ablation circle, we collected data on ablation lesion depth surrogates (time of application, delivery power, impedance drop, average contact force, force-time integral [FTI], and AI) and left atrial wall thickness measured by multidetector computer tomography scanning., Results: The anterior and roof walls were the thickest segments of the ablation circle, in which 85.8% of gaps concentrated, while the posterior and inferior walls were the thinnest. Gap formation was significantly associated with FTI, AI, wall thickness, FTI/wall thickness, and AI/wall thickness. AI/wall thickness had the highest predictive value for gap formation, with a cutoff of 195.6 au/mm for effective ablation., Conclusions: In AI-guided PVI of PAF, AI/wall thickness by normalizing myocardial thickness variation along the WACA circle was a strong predictor of gap formation, with a target of 195.6 au/mm appearing suitable for effective ablation., (© 2020 Wiley Periodicals LLC.)

Introduction: Left atrial posterior wall (LAPW) isolation may be performed as an additional atrial fibrillation (AF) ablation strategy based on pulmonary vein isolation. A modified posterior-inferior line (MPL) was proposed for reducing esophageal injury. The aim of this study was to evaluate the anatomical characteristics of the MPL, compared with the conventional posterior line (CPL)., Methods and Results: Multidetector computed tomography was performed in 102 consecutive AF patients (male/female = 60/42) preoperative, and the parameters were evaluated as follows: the distance from MPL and CPL to the esophagus, fat pad presence and thickness in the course of MPL and CPL, and the esophageal route below CPL. The average distance from the MPL to the esophagus was longer than from CPL to the esophagus (3.7 ± 1.5 vs. 1.7 ± 0.4 mm, p < .001). Proportion of fat pad was higher in the course of MPL than CPL. The myocardium tissue and fat pad under MPL was thicker than under CPL (2.9 ± 1.1 vs. 1.6 ± 0.3 mm, p < .001; 1.4 ± 0.6 vs. 0.9 ± 0.2 mm, p < .001), respectively. In patients whose esophagus was unconfined in a triangular space at the left inferior pulmonary vein level, the average distance from MPL to esophagus was longer than the confined patients (4.0 ± 1.7 vs. 3.2 ± 1.0 mm, p = .001)., Conclusion: The MPL was far away from the esophagus with thicker myocardium tissue and more fat pad than the CPL; thus, MPL could serve as a favorable alternative in linear ablation for LAPW isolation., (© 2020 Wiley Periodicals LLC.)

Background: Data on the incidence, clinical characteristics, and implications of acute conduction recurrence during mitral isthmus (MI) ablation are scarce., Methods: MI ablation was performed in patients with atrial fibrillation. After confirming bidirectional conduction block, the acute conduction recurrence of MI was systematically evaluated. Clinical and electrophysiological characteristics were analyzed., Results: A total of 66 consecutive patients in whom bidirectional conduction block of MI was achieved were prospectively enrolled in a single center. Acute conduction recurrence of MI developed in 12 (18.2%) patients within 14.2 ± 11.5 minutes after the confirmation of bidirectional conduction block. There were two recurrent conduction breakthrough sites of MI along the course of the great cardiac vein (4.5 ± 3.5 min) in two patients and 11 along the course of the ligament of Marshall (LOM) (16.0 ± 11.6 min, P = .035) in 11 patients. LOM accounted for most (84.6%, 11/13) acute MI conduction recurrence. MI length, total ablation time, and procedure time for MI were greater in patients with acute conduction recurrence than in those without acute conduction recurrence. During follow-up, arrhythmia recurrences were less observed in patients with acute conduction when compared to patients without acute conduction recurrence (0% vs 26.4%, P = .055)., Conclusion: Acute conduction recurrence, predominantly due to recurrent LOM conduction, was a common phenomenon during MI ablation, and its evaluation should therefore be the focus to improve MI ablation efficacy and durability., (© 2020 Wiley Periodicals LLC.)

Aims: The mechanisms of the QRS complex axis deviation changing of idiopathic left fascicular ventricular tachycardia (FVT) during or after radiofrequency catheter ablation were investigated in this study, which were still not well defined., Methods and Results: In the index procedure, FVTs characterized by right bundle branch block configuration and left-axis deviation (LAD-FVT) were ablated at the VT exit site guided by the earliest ventricular activation with fused presystolic Purkinje potential (PP) in 234 consecutive patients. A new type of FVT characterized by right-axis deviation (RAD-FVT) was identified after successful elimination of the LAD-FVT in 12 patients, including 9 patients during the index procedure and 3 patients during follow-up. The QRS duration of RAD-FVT was shorter than that of LAD-FVT (115.3 ± 15.2 vs. 125.3 ± 16.4 ms, P = 0.006). The RAD-FVTs showed an earliest ventricle activation site localized at anterior fascicle area in 11 patients and anterior-median fascicle area in 1. However, the earliest PP during the RAD-FVT was still identified within the posterior fascicular network. Elimination of the RAD-FVTs was successfully achieved by applying radiofrequency current at a more proximal site within the left posterior fascicular network guided by the earliest PP. After a mean of 1.6 ± 0.8 ablation procedures and median follow-up of 132 (range 19-216) months since the last procedure, no recurrence was observed in any patients., Conclusion: The axis deviation changing of QRS complex in FVT may be attributed to the different exit sites of the reentry., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Aim: To evaluate the clinical safety and efficacy of radiofrequency catheter ablation for atrial fibrillation (AF) in patients aged ≥80 years., Methods: A total of 333 AF patients aged ≥60 years were enrolled, who underwent contact force-guided radiofrequency catheter ablation with uninterrupted anticoagulation. All patients were followed-up for at least 12 months. Success was defined by the absence of episodes of AF/atrial tachycardia lasting more than 30 seconds after a 3-month blanking period, without antiarrhythmic drugs., Results: Compared to patients aged 60-79 years (Group 2, n = 244), patients aged ≥80 years (Group 1, n = 89) were presented with higher rate of diabetes (36.0% vs 22.1%, P = .011), lower body mass index (23.4 ± 3.1 vs 24.9 ± 3.4 kg/m 2 , P = .001), lower creatinine clearance (56.9 ± 16.5 vs 83.3 ± 24.5 mL/min, P < .001), higher CHA 2 DS 2 -VASc score (4.3 ± 1.3 vs 3.3 ± 1.4, P < .001), and HAS-BLED score (2.2 ± 0.8 vs 1.8 ± 0.8, P < .001). Wide antral pulmonary vein isolation was achieved in all patients, and there was no significant difference in procedure time, ablation time, fluoroscopy time, and complications rate between two age groups (P > .05). After a mean follow-up of 24.4 ± 9.6 months, the overall success rate was 78.2% in Group 1 and 78.9% in Group 2 (P = .622)., Conclusions: Radiofrequency ablation with contact force sensing catheters for AF is safe and effective in selected patients aged ≥80 years., (© 2020 Wiley Periodicals LLC.)

Background: Premature ventricular complex (PVC) with narrow QRS duration originating from proximal left anterior fascicle (LAF) is challenging for ablation. This study was performed to evaluate the safety and feasibility of ablation from right coronary cusp (RCC) for proximal LAF-PVC and to investigate this PVC's characteristics., Methods: Mapping at RCC and left ventricle and ECG analysis were performed in 20 patients with LAF-PVC., Results: The earliest activation site (EAS), with Purkinje potential during both PVC and sinus rhythm, was localized at proximal LAF in 8 patients (proximal group) and at nonproximal LAF in 12 patients (nonproximal group). The Purkinje potential preceding PVC-QRS at the EAS in proximal group (32.6±2.5 ms) was significantly earlier than that in nonproximal group (28.3±4.5 ms, P =0.025). Similar difference in the Purkinje potentials preceding sinus rhythm QRS at the EAS was also observed between proximal and nonproximal groups (35.1±4.7 versus 25.2±5.0 ms, P <0.001). In proximal group, the distance between the EAS to left His bundle and to RCC was shorter than that of nonproximal group (12.3±2.8 versus 19.7±5.0 mm, P =0.002, and 3.9±0.8 versus 15.7±7.8 mm, P <0.001, respectively). No difference in the distance from RCC to proximal LAF was identified between the 2 groups. PVCs were successfully eliminated from RCC for all proximal groups but at left ventricular EAS for nonproximal groups. The radiofrequency application times, ablation time, and procedure time of nonproximal group were longer than that of proximal group. Electrocardiographic analysis showed that, when compared with nonproximal group, the PVCs of proximal group had narrower QRS duration; smaller S wave in leads I, V 5 , and V 6 ; lower R wave in leads I, aVR, aVL, V 1 , V 2 , and V 4 ; and smaller q wave in leads III and aVF. The QRS duration difference (PVC-QRS and sinus rhythm QRS) <15 ms predicted the proximal LAF origin with high sensitivity and specificity., Conclusions: PVCs originating from proximal LAF, with unique electrocardiographic characteristics, could be eliminated safely from RCC.

Aims: Mitral isthmus (MI) ablation is challenging. We hoped to close those conduction breakthrough sites (CBS) across the MI by elaborate mapping., Methods and Results: After the initial linear ablation, elaborately mapping large areas above and below the MI line and inside the coronary sinus (CS) was sequentially performed to identify the CBS. The shortest distance from the CBS to the MI line was measured. The distant CBS (D-CBS) was identified as those CBS >5.0 mm away from the MI line. We prospectively enrolled 177 consecutive patients. Bidirectional conduction blockage across MI was obtained in 50 (28.2%) patients after the initial linear ablation and was achieved in additional 115 (65.0%) patients following elaborate mapping and reinforcement ablation. After initial linear ablation, 272 CBS (2.14 ± 0.99 CBS/person) were identified, and 226 (83.1%) of them were characterized as D-CBS, including 98 sites (36.0%) >10.0 mm and 39 sites (14.3%) >15.0 mm away. Endocardial and epicardial (CS) reinforcement ablation eliminated 119/272 (43.8%) and 58/272 (21.3%) CBS, respectively. Among the 177 eliminated CBS, 138 D-CBS (78.0%, 11.2 ± 5.6 mm) were confirmed in 95 (74.8%) patients. Moreover, CBS along the course of ligament of Marshall was closed by endocardial ablation more frequently than that along the course of great cardiac vein (52.6%% vs. 35.1%, P = 0.004). Eventually, CS ablation was required only in 64 (38.8%) patients., Conclusion: Distant CBS, accounted for the majorities of the residual conduction across the MI after initial ablation, could be effectively identified and accurately eliminated by elaborate mapping and ablation around the MI ablation line., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Background: The influence of procedural arrhythmia termination on long-term single-procedure clinical outcome in patients with non-paroxysmal atrial fibrillation (AF) remains controversial., Methods: An individualized stepwise ablation strategy was used in 200 consecutive patients with non-paroxysmal AF who underwent first-time radiofrequency catheter ablation, with pulmonary vein isolation and sinus rhythm (SR) restoration as the primary endpoints., Results: SR was restored by ablation in 94 patients, including 32 with AF directly and 62 with intermediate atrial tachycardia (AT). Cardioversion was performed to restore SR in 106 patients, including 31 with intermediate AT, and 75 with sustained AF. During a mean follow-up of 50.0 ± 9.3 months, single-procedure success was achieved in 99 (49.5%) patients. There was a significant difference in long-term success between patients with SR restoration by ablation and by cardioversion (63.8% vs 36.8%; P < 0.001), but not between patients with AF termination by ablation and by cardioversion (53.6% vs 42.7%; P = 0.146). SR restoration by ablation (odds ratio = 3.032; 95% confidence interval = 1.703-5.398; P < 0.001) was the only predictor of single-procedure success by logistic regression analyses. In patients with intermediate AT (n = 93), AT termination by ablation was associated with a higher success rate than AT termination by cardioversion (62.9% vs 22.6%; P < 0.001)., Conclusions: SR restoration and AT termination by ablation were both associated with an improved long-term single-procedure clinical outcome in patients with non-paroxysmal AF., (© 2013 Wiley Periodicals, Inc.)

Aims: The mechanisms of the QRS complex axis deviation changing of idiopathic left fascicular ventricular tachycardia (FVT) during or after radiofrequency catheter ablation were investigated in this study, which were still not well defined.Methods and Results: In the index procedure, FVTs characterized by right bundle branch block configuration and left-axis deviation (LAD-FVT) were ablated at the VT exit site guided by the earliest ventricular activation with fused presystolic Purkinje potential (PP) in 234 consecutive patients. A new type of FVT characterized by right-axis deviation (RAD-FVT) was identified after successful elimination of the LAD-FVT in 12 patients, including 9 patients during the index procedure and 3 patients during follow-up. The QRS duration of RAD-FVT was shorter than that of LAD-FVT (115.3 ± 15.2 vs. 125.3 ± 16.4 ms, P = 0.006). The RAD-FVTs showed an earliest ventricle activation site localized at anterior fascicle area in 11 patients and anterior-median fascicle area in 1. However, the earliest PP during the RAD-FVT was still identified within the posterior fascicular network. Elimination of the RAD-FVTs was successfully achieved by applying radiofrequency current at a more proximal site within the left posterior fascicular network guided by the earliest PP. After a mean of 1.6 ± 0.8 ablation procedures and median follow-up of 132 (range 19-216) months since the last procedure, no recurrence was observed in any patients.Conclusion: The axis deviation changing of QRS complex in FVT may be attributed to the different exit sites of the reentry. [ABSTRACT FROM AUTHOR]

Aims: Mitral isthmus (MI) ablation is challenging. We hoped to close those conduction breakthrough sites (CBS) across the MI by elaborate mapping.Methods and Results: After the initial linear ablation, elaborately mapping large areas above and below the MI line and inside the coronary sinus (CS) was sequentially performed to identify the CBS. The shortest distance from the CBS to the MI line was measured. The distant CBS (D-CBS) was identified as those CBS >5.0 mm away from the MI line. We prospectively enrolled 177 consecutive patients. Bidirectional conduction blockage across MI was obtained in 50 (28.2%) patients after the initial linear ablation and was achieved in additional 115 (65.0%) patients following elaborate mapping and reinforcement ablation. After initial linear ablation, 272 CBS (2.14 ± 0.99 CBS/person) were identified, and 226 (83.1%) of them were characterized as D-CBS, including 98 sites (36.0%) >10.0 mm and 39 sites (14.3%) >15.0 mm away. Endocardial and epicardial (CS) reinforcement ablation eliminated 119/272 (43.8%) and 58/272 (21.3%) CBS, respectively. Among the 177 eliminated CBS, 138 D-CBS (78.0%, 11.2 ± 5.6 mm) were confirmed in 95 (74.8%) patients. Moreover, CBS along the course of ligament of Marshall was closed by endocardial ablation more frequently than that along the course of great cardiac vein (52.6%% vs. 35.1%, P = 0.004). Eventually, CS ablation was required only in 64 (38.8%) patients.Conclusion: Distant CBS, accounted for the majorities of the residual conduction across the MI after initial ablation, could be effectively identified and accurately eliminated by elaborate mapping and ablation around the MI ablation line. [ABSTRACT FROM AUTHOR]

A 65‐year‐old woman was referred for catheter ablation in the treatment of persistent tachycardia after surgery for atrial fibrillation and mitral regurgitation. Bipolar voltage mapping of both atria revealed that severe and extensive atrial fibrosis isolated the sinoatrial node from the atrioventricular junction and led to the coexistence of sinus bradycardia and persistent junctional tachycardia. [ABSTRACT FROM AUTHOR]

ABSTRACT Background Methods Results Conclusion Transseptal catheterization is critical for atrial fibrillation (AF) ablation but risks thromboembolism. Transseptal sheaths (TSS) were suggested for continuous heparinized saline solution flush. The safety and effectiveness of a simple TSS management to reduce sheath‐associated thrombus development risk was investigated.AF patients who underwent radiofrequency ablation with the simple TSS management were studied under a retrospective multi‐center observation study and a prospective single‐center observation study. TSS and dilators were washed and perfused with high concentration heparinized saline (20 u/mL). Immediately after two successful transseptal punctures, activated clotting time ≥300 s was maintained by heparin infusion. TSS aspiration with negative suction and re‐perfusion with high concentration heparinized saline (20 u/mL) was performed for the remaining procedure before and after catheter withdrawal.A total of 4765 AF patients underwent 5367 ablation procedures were enrolled in the retrospective study, involving 156 (2.9% per procedure) complications. No acute stroke occurred during all the procedures. Perioperative thromboembolic complications occurred in 10 (0.21%) patients and in 10 (0.19%) procedures. Thromboembolic complications occurred within 24 h, between 24–48 h, and after 48 h post‐procedure in six, two, and two patients, respectively. In the prospective observation study, neither sheath‐ nor catheter‐associated thrombus were detected by the intracardiac echocardiography during all 127 procedures, without any perioperative thromboembolic complications. No hemorrhagic cerebrovascular complication was encountered in both observational studies.For AF radiofrequency ablation, it was safe and effective for TSS high concentration heparinized saline infusion only. This approach could avoid sheath‐associated thrombus for interventional procedures. [ABSTRACT FROM AUTHOR]