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As a new energy source for atrial fibrillation ablation, electric pulse ablation has higher tissue selectivity and biosafety, so it has a great application prospect. At present, there is very limited research on multi-electrode simulated ablation of histological electrical pulse. In this study, a circular multi-electrode ablation model of pulmonary vein will be built on COMSOL5.5 platform for simulation research. The results show that when the voltage amplitude reaches about 900 V, it can make some positions achieve transmural ablation, and the depth of continuous ablation area formed can reach 3 mm when the voltage amplitude reaches 1 200 V. When the distance between catheter electrode and myocardial tissue is increased to 2 mm, a voltage of at least 2 000 V is required to make the depth of continuous ablation area reach 3 mm. Through the simulation of electric pulse ablation with ring electrode, the research results of this project can provide reference for the voltage selection in the clinical application of electric pulse ablation.

Background: Pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF) is associated with a non-negligible long-term recurrence rate., Objectives: The purpose of this study was to investigate whether PVI combined with 6 short ablation lines on the PVI circumferences (PVI+6L group) yields higher success rates than PVI alone (PVI group)., Methods: In this multicenter, single-blind, randomized trial, a total of 390 patients with paroxysmal AF were randomly assigned to the PVI group (n = 193) or the PVI+6L group (n = 197). The primary endpoint was freedom from AF/atrial tachycardia recurrence between 91 and 365 days. Secondary endpoints included AF burden, procedural parameters, and complications., Results: Freedom from atrial tachyarrhythmia was achieved in 160 of 197 patients (81.2%) in the PVI+6L group and 142 of 193 patients (73.6%) in the PVI group (hazard ratio 0.61; 95% confidence interval 0.39-0.97; P = .040). Mean AF burden tended to be lower in the PVI+6L group compared to the PVI group (1.95% vs 0.53%, P = .097). Procedural and ablation times were slightly longer in the PVI+6L group than in the PVI group (130 ± 25 minutes vs 121 ± 28 minutes; P = .002; and 46 ± 14 minutes vs 41 ± 16 minutes, P = .001, respectively). X-ray exposure was similar (60 ± 54 seconds vs 61 ± 60 seconds; P = .964). Complications occurred in 3 patients (1.6%) in the PVI group and 3 patients (1.5%) in the PVI+6L group., Conclusion: In patients with paroxysmal AF undergoing catheter ablation, adding 6 short ablation lines on the PVI circumferences could reduce the AF recurrence rate., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Premature ventricular complexes (PVCs) exhibit circadian fluctuation. We determine if PVCs of different origin exhibit specific circadian patterns., Methods: We analyzed Holter recordings from patients with monomorphic PVCs who underwent catheter ablation. PVC circadian patterns were classified as fast-heart rate- (HR-) dependent (F-PVC), slow-HR-dependent (S-PVC), or HR-independent (I-PVC). PVC origins were determined intraprocedurally., Results: In a retrospective cohort of 407 patients, F-PVC and S-PVC typically exhibited diurnal and nocturnal predominance, respectively. Despite decreased circadian fluctuation, I-PVC generally had heavier nocturnal than diurnal burden. PVCs of left anterior fascicle origin were predominantly S-PVC, while those of posterior hemibranch origin were mostly F-PVC. PVCs originating from the aortic sinus of Valsalva (ASV) were predominantly I-PVC, while most PVCs arising from the left ventricular outflow tract (LVOT) were F-PVC. Using a diurnal/nocturnal PVC burden ratio of 0.92 as the cutoff value to distinguish LVOT from ASV origin achieved 97% sensitivity and, as further verification, an accuracy of 89% (16/18) in a prospective cohort of patients with PVCs originating from either ASV or LVOT. In contrast, PVCs originating from right ventricles, such as right ventricular outflow tract, did not show distinct circadian patterns., Conclusions: The circadian patterns exhibit origin specificity for PVCs arising from left ventricles. An analysis of Holter monitoring provides useful information on PVC localization in ablation procedure planning., Competing Interests: The authors declare that there are no conflicts of interest., (Copyright © 2020 Mu Chen et al.)

Background: Primary angiosarcomas of the right atrium are extremely rare, often resulted in missed diagnosis or misdiagnosis with routine examination tools. These malignant cardiac tumors are highly aggressive with generally poor prognosis. Surgical excision is the mainstay of treatment as it is essentially not responsive to current regimens of chemoradiotherapy., Case Presentation: Herein, we describe a patient who initially presented with paroxysmal atrial fibrillation and was subsequently treated with radiofrequency catheter ablation (RFCA). Prior to RFCA, an initial transesophageal echocardiography revealed a local thickening of the intratrial septum. Three months later, she was hospitalized with progressive dyspnea and massive pericardial effusion. A large immobile, non-pedunculated mass, occupying almost half of the right atrium was detected by transthoracic and transesophageal echocardiogram. Multimodality cardiac imaging was useful in further characterizing this mass, which was ultimately diagnosed as an angiosarcoma based upon biopsy results. The growth rate was extremely rapid following RFCA, and patient underwent surgical excision. After discharge, the angiosarcoma recurred and patient survived for 7 months from the first episode of tamponade., Conclusions: Primary cardiac angiosarcoma of the right atrium can easily be mistaken for structural anomalies in its early stages, losing the opportunity for initiating earlier treatments to improve potential patient outcomes. The correct diagnosis of this rare case relied on the comprehensive utilization of multimodal imaging techniques including biopsy.

Purpose: Previous studies showed that genetic variants of the angiotensinogen (AGT) gene conferred higher risk for acquired atrial fibrillation (AF). The present study investigated whether AGT variants correlate with the clinical outcome in patients with acquired AF after catheter ablation (CA)., Methods: A total of 150 acquired symptomatic drug-refractory AF patients (mean age 63.7±11.0 years, 24.6% non-paroxysmal AF) with acquired AF underwent a single CA procedure in our department and were included in this retrospective analysis. Eight tagging single nucleotide polymorphisms (tSNPs) in the AGT gene were genotyped. Standard electrocardiographs (ECGs) and 24-hour Holter recordings were performed during a median follow-up period of 57.5 months to detect AF recurrence., Results: Sixty-one patients (40.7%) suffered AF recurrences after a single CA procedure during follow up. Of the eight tSNPs, the frequency of the M allele of M235T was significantly higher in the recurrence group (28%) compared to the non-recurrence group (18%) (p=0.042). The recurrence rates of patients with the TT, MT, and MM genotypes were 34.4%, 50%, and 55.6%, respectively (ptrend=0.049). After adjusting for age, sex, body mass index, hypertension, left atrial volume index (LAVI) and other covariates, M235T increased the risk of AF recurrence in additive and dominant models with odds ratios of 2.023 (95% confidence interval (CI): 1.034-3.926, p=0.033) and 2.601 (95% CI: 1.102-6.056, p=0.025), respectively. However, in multiple correction analyses, the p values of multiple comparisons were not statistically significant (pcorrect>0.05)., Conclusions: The M allele of M235T might be associated with an increased risk of AF recurrence after CA. Genotyping may thus be helpful on identifying patients with higher risks of AF recurrence after CA and developing optimal follow-up strategies. These strategies may differ and should be individualized according to patients' genotype. Future studies are warranted to validate the potential effect of AGT M235T on AF recurrence post CA., (© The Author(s) 2015.)

Objective: To investigate the association between CHADS2 score and long-term ( ≥ 3 years) outcomes post catheter ablation in patients with atrial fibrillation (AF)., Methods: AF patients who received single catheter ablation in our hospital from January 2004 to March 2009 in our department were included and patients received regular follow-up. AF recurrence was defined as the occurrence of atrial arrhythmias (AF, atrial flutter and atrial tachycardia) recorded by electrocardiogram monitor ( ≥ 30 seconds) after ablation during follow-up period (after 3 months blanking period). The relationship between baseline clinical and echocardiographic characteristics and the time to recurrence during follow-up was evaluated using Cox multivariate analysis., Results: A total of 280 patients who received single catheter ablation procedure were included in the study, 3 patients died and there were 50 patients lost to follow-up. A total of 227 patients with AF (163 paroxysmal and 64 non-paroxysmal ) were enrolled in the final analysis. During a median follow-up of 51 months (41-56 months), 109 patients experienced AF recurrences and the recurrence rate after catheter ablation ( ≥ 3 years) was 48.0% (109/227). Cox multivariate analysis showed that the high CHADS2 score (HR: 1.417, 95%CI 1.194-1.682, P < 0.001) and AF non-termination during ablation (HR: 2.077, 95%CI 1.380-3.126, P = 0.043) were risk factors of AF recurrence. AF recurrence rates in the termination and non-termination group were 41.0% (75/183) and 77.3% (34/44), respectively. In the AF termination group, the recurrence rates and the median recurrence free time in patients with CHADS2 score ≥ 3 were 80.0% (12/15) and 1 year, respectively. In the non-AF termination group, the recurrence rates in patients with CHADS2 score = 0, CHADS2 score = 1-2 and CHADS2 score ≥ 3 were 60.0% (6/10), 77.8% (21/27) and 100% (7/7), respectively; the median recurrence free time of patients with CHADS2 score = 0, CHADS2 score = 1-2 and CHADS2 score ≥ 3 were 30 months, 12 months and 6 months, respectively., Conclusions: CHADS2 score is a predictor of AF recurrences after catheter ablation. Patients with high CHADS2 score is associated with higher risk of long-term ( ≥ 3 years) AF recurrences.

Aims: Bronchi or pulmonary arteries (PAs) could be injured during atrial fibrillation (AF) ablation. Therefore, the aim of the present study was to evaluate the spatial relationship between left atrial roof or superior pulmonary veins (PVs) and neighbouring structures of AF patients and provide anatomic guidance for AF ablation to avoid injuring bronchi or PAs., Methods and Results: A dual-source computed tomography (DSCT) scan was used to depict the left atrium (LA), PVs, and nearby structures including bronchi and PAs in 58 patients with drug-refractory AF (mean age, 64 ± 9 years). The distance between LA roof or superior PVs (SPVs) and bronchi or PAs was measured. The average minimal distances from the left, middle, and right points of the LA roof to the principal bronchi were 17.0 ± 6.4, 23.7 ± 5.1, and 23.2 ± 7.7 mm, respectively. The LA roof was closer to the right PA (RPA) than the left PA (LPA) for more than 90% of patients. The average minimal distances from the left, middle, and right points of the LA roof to the PAs were 8.3 ± 5.0, 5.9 ± 3.1, and 6.0 ± 2.8 mm, respectively. The average minimal distances between the left superior pulmonary vein and bronchi or LPA were 0.32 ± 0.79 or 0.4 ± 1.0 mm, respectively. The average minimal distances between the right superior pulmonary vein and bronchi or RPA were 0.27 ± 0.94 and 0.0 ± 0.1 mm, respectively. Both of the root parts of SPVs of most patients were in direct contact with branches of trachea and PAs., Conclusion: Dual-source computed tomography provides important imaging information for determining the relationship between LA, PVs, and neighbouring structures. Use of pre-procedural cardiac CT scans may help avoid ablation-induced injury of bronchi and PAs.