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Lesion gaps assessed by late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) are associated with the atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Animal studies have demonstrated that the catheter-contact force (CF), stability, and orientation are strongly associated with lesion formation. However, the impact of those procedural factors on the lesion characteristics associated with AF recurrence has not been well discussed.A total of 30 patients with paroxysmal AF who underwent catheter ablation were retrospectively enrolled. Radiofrequency (RF) applications were performed with 35W for 30s in a point-by-point fashion under esophageal temperature monitoring. The inter-lesion distance was 4mm. The lesions were visualized by LGE-MRI three months post-procedure and assessed by the LGE volume (ml), gap number (GN), and average gap length (AGL [mm]). The gaps were defined as non-enhancement sites of4 mm. The procedural factors including the catheter-CF, stability, and orientation were calculated on the NavX system.Six (20%) of 30 patients had AF recurrences 12 months post-ablation. A univariate analysis demonstrated that the AGL was associated with AF recurrence (hazard ratio [HR]: 1.20, confidence interval [CI]:1.03 - 1.42, p = 0.02). All AF recurrence were found in patients with an AGL of7 mm. The catheter-CF and stability were associated with an AGL of7mm, but not the orientation (CF: HR: 0.62, CI: 0.39-0.97, p=0.038; stability: HR: 0.8, CI: 0.66-0.98, p=0.027).RF ablation with a low CF and poor catheter stability has a potential risk of creating large lesion gaps associated with AF recurrence. This article is protected by copyright. All rights reserved.

Background: The mechanism underlying the sex differences in atrial fibrillation (AF) recurrence following pulmonary vein (PV) isolation is not fully understood. We hypothesized that non-PV foci and epicardial adipose tissue (EAT) play a key role. Methods and Results: Data from 304 consecutive patients (75% males) who underwent contrast-enhanced computed tomography and catheter ablation of AF were reviewed. The EAT around the atrium was measured separately in 4 parts of the atrium. All patients underwent high-dose isoproterenol infusions to assess the non-PV foci. Significantly more non-PV foci and less EAT around the atrium were observed in female patients than in male patients. In males, those with non-PV foci on the left atrial (LA) anterior wall had significantly greater EAT for the same lesions than those without non-PV foci. During a median follow-up of 27 months, the predictors of AF recurrence after first catheter ablation were female sex, presence of non-PV foci, LA diameter, and septal EAT index. A sex-specific analysis revealed that LA diameter was a predictor only in males and that the presence of non-PV foci in the septal region was a strong predictor in males (hazard ratio [HR]: 2.24) and females (HR: 3.65). Conclusions: Sex-specific differences were observed in non-PV foci sites and local EAT and in regard to the predictors of AF recurrence.

Background: Ventricular tachycardia (VT) non-inducibility at the end of ablation is associated with a less likely VT recurrence. However, it is not clear whether we should use VT non-inducibility as a routine end point of VT ablation. The aim of this study was to evaluate VT recurrence in patients in whom VT non-inducibility was not achieved at the end of the RF ablation and the factors attributing to the VT recurrence.Methods: We analyzed 62 patients in whom VT non-inducibility was not achieved at the end of the RF ablation were studied.Results: Over 2 years, 22 (35%) of the cases had VT recurrences. A multivariate analysis showed that an LVEF≥35% (HR:0.19; 95% CI:0.06- 0.49; PConclusion: Even if VT non-inducibility was not achieved, patients with an LVEF≥35% or in whom partial success could be achieved might be prevented from having VT recurrences. The validity of the VT non-inducibility of any VT should be evaluated considering each patient’s background and the results of the procedure.

The skin overlying cardiovascular implantable electronic devices (CIEDs) sometimes becomes very thin after implantations, which could cause a device erosion. The factors related to the skin thickness of device pockets have not been elucidated. This study aimed to evaluate the skin thickness of CIED pockets and search for the factors associated with the thickness.Seventeen skin thickness points around the CIED pocket were measured through ultrasonography in each patient.A total of 101 patients (76 ± 11 years, 26 female) were enrolled. The median duration from the implantation to the examination was 95 months (quartile: 52.5-147.5). The median skin thickness overlying the device was 4.1 mm (3.3-5.9). Patients with heart failure and malignancy had thinner skin overlying the CIED than those without. A significant correlation existed between skin thickness and body mass index (BMI), hemoglobin, serum creatinine, estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction. In contrast, age, gender, and device size did not exhibit a significant correlation with skin thickness. A multivariate logistic regression analysis revealed that chronic heart failure and a decrease in the eGFR and BMI were independent predictive factors of "very thin (≦3.3 mm)" skin of the CIED pocket late after an implantation.Aside from a low BMI, the comorbidities (low hemoglobin, heart failure, and renal dysfunction) had a stronger impact on the skin thickness overlying the device than the device size. A careful observation of the device pocket should be performed in patients with those risk factors.

A recent randomized trial demonstrated that catheter ablation for atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (EF) is associated with a reduction in death or heart failure. However, the effect of catheter ablation for AF in patients with heart failure with mid-range or preserved EF is unclear.Methods and Results: We screened 899 AF patients (72.4% male, mean age 68.4 years) with heart failure and left ventricular EF ≥40% from 2 Japanese multicenter AF registries: the Atrial Fibrillation registry to Follow the long-teRm Outcomes and use of aNTIcoagulants aftER Ablation (AF Frontier Ablation Registry) as the ablation group (525 patients who underwent ablation) and the Hokuriku-Plus AF Registry as the medical therapy group (374 patients who did not undergo ablation). Propensity score matching was performed in these 2 registries to yield 106 matched patient pairs. The primary endpoint was a composite of cardiovascular death and hospitalization for heart failure. At 24.6 months, the ablation group had a significantly lower incidence of the primary endpoint (hazard ratio 0.32; 95% confidence interval 0.13-0.70; P=0.004) than the medical therapy group.Compared with medical therapy, catheter ablation for AF in patients with heart failure and mid-range or preserved EF was associated with a significantly lower incidence of cardiovascular death or hospitalization for heart failure.

This study sought to assess the left atrial (LA) functional recovery after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) and to evaluate the determining factor of procedural success of RFCA, using a novel preload stress echocardiography. A total of 111 patients with AF were prospectively recruited. The echocardiographic parameters were obtained during the leg-positive pressure (LPP) maneuver, both at baseline and midterm after RFCA. As an index of LA distensibility, the LA expansion index was calculated as (LAVsubmax/sub- LAVsubmin/sub) × 100 / LAVsubmin/sub. During a median follow-up period of 14.2 months, AF recurrence was observed in 23 patients (20.7%). In LA functional parameters at baseline, only the Δ LA expansion index was significantly larger in the success group (16 ± 11% vs 4 ± 9%, plt;0.05). At midterm follow-up, the Δ LA expansion index significantly increased to 32 ± 19% (plt;0.05), together with structural LA reverse remodeling only in the success group. Moreover, the Δ stroke volume index during the LPP stress test significantly increased only in the success group (from 2.3 ± 1.3 ml/msup2/supto 3.1 ± 4.8 ml/msup2/sup, plt;0.05). In a multivariate analysis, left ventricular ejection fraction (hazard ratio 0.911, plt;0.05) and baseline Δ LA expansion index (hazard ratio 0.827, plt;0.001) were independent predictors of AF recurrence. In conclusion, the baseline Δ LA expansion index during LPP stress is a reliable marker for predicting procedural success after RFCA. Moreover, maintenance of sinus rhythm resulted in an improvement of the preload reserve after RFCA.

Background: Several algorithms have been proposed for differentiating the right and left outflow tracts (RVOT/LVOT) arrhythmia origins from 12-lead electrocardiograms (ECGs); however, the procedure is complicated. A deep learning (DL) model, a form of artificial intelligence, can directly use ECGs and depict the importance of the leads and waveforms. This study aimed to create a visualized DL model that could classify arrhythmia origins more accurately.Methods and Results: This study enrolled 80 patients who underwent catheter ablation. A convolutional neural network-based model that could classify arrhythmia origins with 12-lead ECGs and visualize the leads that contributed to the diagnosis using a gradient-weighted class activation mapping method was developed. The average prediction results of the origins by the DL model were 89.4% (88.2–90.6) for accuracy and 95.2% (94.3–96.2) for recall, which were significantly better than when a conventional algorithm is used. The ratio of the contribution to the prediction differed between RVOT and LVOT origins. Although leads V1 to V3 and the limb leads had a focused balance in the LVOT group, the contribution ratio of leads aVR, aVL, and aVF was higher in the RVOT group.Conclusions: This study diagnosed the arrhythmia origins more accurately than the conventional algorithm, and clarified which part of the 12-lead waveforms contributed to the diagnosis. The visualized DL model was convincing and may play a role in understanding the pathogenesis of arrhythmias.

IntroductionData are lacking on the extent to which patients with non-valvular atrial fibrillation (AF) who are aged ≥80 years benefit from ablation treatment. The question pertains especially to patients’ postablation quality of life (QoL) and long-term clinical outcomes.Methods and analysisWe are initiating a prospective, registry-based, multicentre observational study that will include patients aged ≥80 years with non-valvular AF who choose to undergo treatment by catheter ablation and, for comparison, such patients who do not choose to undergo ablation (either according to their physician’s advice or their own preference). Study subjects are to be enrolled from 52 participant hospitals and three clinics located throughout Japan from 1 June 2022 to 31 December 2023, and each will be followed up for 1 year. The planned sample size is 660, comprising 220 ablation group patients and 440 non-ablation group patients. The primary endpoint will be the composite incidence of stroke/transient ischaemic attack (TIA) or systemic embolism (SE), another cardiovascular event, major bleeding and/or death from any cause. Other clinical events such as postablation AF recurrence, a fall or bone fracture will be recorded. We will collect standard clinical background information plus each patient’s Clinical Frailty Scale score, AF-related symptoms, QoL (Five-Level Version of EQ-5D) scores, Mini-Mental State Examination (optional) score and laboratory test results, including measures of nutritional status, on entry into the study and 1 year later, and serial changes in symptoms and QoL will also be secondary endpoints. Propensity score matching will be performed to account for covariates that could affect study results.Ethics and disseminationThe study conforms to the Declaration of Helsinki and the Ethical Guidelines for Clinical Studies issued by the Ministry of Health, Labour and Welfare, Japan. Results of the study will be published in one or more peer-reviewed journals.Trial registration numberUMIN000047023.

Introduction: It has been reported that ventricular tachycardia (VT) non-inducibility at the end of ablation is associated with less likely VT recurrence. However, it is not clear whether we should use VT non-inducibility as routine end point in VT ablation. The aim of this study was to evaluate VT recurrence in patients in whom VT non-inducibility could not be achieved at the end of the RF ablation and the factors attributing to the VT recurrence. METHODS and RESULTS: We analyzed 84 consecutive patients that underwent RF ablation, and 64 patients in whom VT non-inducibility could not be achieved were studied. The primary endpoint was recurrence of any sustained VT during the follow-up. During a median follow-up period of 1.4 years (IQR:0.3-2.0), 22 (34%) of the cases had VT recurrences. In the multivariate analysis showed that an LVEF≥35% (HR:0.21; 95% CI:0.07- 0.54; P

The management of heart rhythm disorders in patients with adult congenital heart disease and limited vascular access is challenging. We present the case of a 38-year-old woman with Ebstein’s anomaly who underwent implantation of a combination of a leadless pacemaker and a subcutaneous implantable cardioverter-defibrillator to manage fatal arrhythmias. (Level of Difficulty: Intermediate.)