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The neuromodulation effect after ventricular arrhythmia (VA) ablation is unclear. The study aimed to investigate skin sympathetic nerve activity (SKNA) changes in patients receiving catheter ablations for idiopathic VA.Of 43 patients with drug-refractory symptomatic VA receiving ablation, SKNA was continuously recorded for 10 min during resting from electrocardiogram lead I configuration and bipolar electrodes on the right arm 1 day before and 1 day after ablation.Twenty-two patients with acute procedure success and no recurrence during follow-ups were classified as sustained success group (group 1). Other 21 patients were classified as failed ablation group (group 2). Baseline SKNA showed no significant difference between the two groups. Post-ablation SKNA in group 2 was significantly higher than in group 1. In patients with ablation involved right ventricular outflow tract (RVOT), the post-ablation SKNA was also significantly higher in group 2. In contrast, there was no difference in post-ablation SKNA between groups in patients receiving non-RVOT ablation.The neuromodulation response after RVOT ablation may correspond to the sympathetic nerve distribution at RVOT. Augmentation of sympathetic activity after VA ablation indicates an unsuccessful VA suppression, especially in patients receiving ablation of RVOT VA.

Radiofrequency catheter ablation (RFCA) is commonly performed in patients with non-paroxysmal atrial fibrillation (AF), but because very long-term follow-up results of RFCA are limited, we investigated the 10-year RFCA outcomes of non-paroxysmal AF.Methods and Results: We retrospectively enrolled 100 patients (89 men, mean age 53.5±8.4years) with drug-refractory symptomatic non-paroxysmal AF who underwent 3D electroanatomic-guided RFCA. Procedural characteristics at index procedures and clinical outcomes were investigated. In the index procedures, all patients had pulmonary vein isolation, 56 (56.0%), 48 (48.0%), and 32 (32.0%) underwent additional linear, complex fractionated atrial electrogram (CFAE) and non-pulmonary vein (NPV) foci ablations, respectively. After 124.1±31.7 months, 16 (16%) patients remained in sinus rhythm after just 1 procedure (3 with antiarrhythmic drugs [AAD]) and after multiple (2.1±1.3) procedures in 53 (53.0%) patients (22 with AAD). Left atrial (LA) diameter (hazard ratio HR 1.061; 95% confidence interval (CI) 1.020 to 1.103; P=0.003), presence of NPV triggers (HR 1.634; 95% CI 1.019 to 2.623; P=0.042) and undergoing CFAE ablation (HR 2.003; 95% CI 1.262 to 3.180; P=0.003) in the index procedure were independent predictors for recurrent atrial tachyarrhythmia.The 10-year outcomes of single RFCA in non-paroxysmal AF were unsatisfactory. Enlarged LA, presence of NPV triggers, and undergoing CFAE ablation in the index procedure independently predicted single-procedure recurrence. Multiple procedures are required to achieve adequate rhythm control.

The recent Atrial Fibrillation Management in Congestive Heart Failure With Ablation (AMICA) trial did not reveal any benefit of catheter ablation in patients with atrial fibrillation (AF), advanced heart failure (HF), and severely reduced left ventricular ejection fraction (LVEF). We hypothesized that radiofrequency catheter ablation (RFCA) could improve outcomes in HF patients with AF and impaired left ventricular systolic function (LVEF50%) as compared with only medical therapy.We searched the literature for randomized clinical trials (RCTs) that compared RFCA to medical therapy in this population.Compared with the medical therapy group, the RFCA group had significantly less all-cause mortality, HF hospitalization, and AF recurrence rates. The RFCA group had significantly higher peak oxygen consumption (VO 2 max), a better quality of life (Minnesota Living with Heart Failure Questionnaire score), and improved LVEF. However, RFCA for AF failed to reduce all-cause mortality in a specific meta-analysis of four RCTs that enrolled patients with LVEF ≤35%.Compared with medical therapy, RFCA for AF in the setting of HF with impaired systolic function is associated with better clinical (HF hospitalization and all-cause mortality), structural (LVEF improvement), functional (VO 2 max), and quality of life outcomes. However, RFCA for AF failed to reduce all-cause mortality in RCTs that enrolled patients with LVEF ≤35%, and thereby indicated the necessary stratification to identify patients who may benefit more from RFCA.

The efficacy of catheter ablation (CA) on clinical outcomes and cardiac structural remodelling in atrial fibrillation (AF) patients with HF with mildly reduced or mid-range ejection fraction (HFmrEF) remains unclear. We aimed to compare the efficacy of CA with medical therapy (MT) in AF patients with HFmrEF.We retrospectively screened a total of 36 879 patients with AF between 2005 and 2020. Patients who were initially diagnosed with echocardiography-proved HFmrEF and had follow-up echocardiography were enrolled. After applying propensity score matching in a 1:1 ratio, 72 patients treated by CA (Group 1) and 72 patients receiving MT (Group 2) were taken into further analysis. The co-morbidities were similar between the two groups, except for hyperlipidaemia. After a mean follow-up duration of 58.9 ± 42.6 months, Group 1 had a lower HF hospitalization and all-cause mortality compared with Group 2 (hazard ratio (HR), 0.089 [95% confidence interval (CI), 0.011-0.747]; P = 0.026 and HR, 0.121 [95% CI, 0.016-0.894]; P = 0.038, respectively). As for cardiac structural remodelling, the Group 1 had a better improvement in left ventricular ejection fraction (LVEF) and a more decreased left atrium (LA) diameter than Group 2 (+25.0% ± 18.0% vs. +6.2% ± 21.6%, P = 0.0001 and -1.6 ± 4.7 mm vs. +1.5 ± 8.2 mm, P = 0.008, respectively).In patients with HFmrEF and AF, CA of AF could reduce both HF hospitalization and all-cause mortality as compared with those with MT. A significant improvement in LVEF and decrease in LA diameter were also observed in the CA group. Early rhythm control with CA should be taken into consideration in patients with HFmrEF and AF.

The presence of bipolar low-voltage zone (LVZ) is a predictor of AF recurrence after PV isolation (PVI). However, changes of wavefront and bipole directions may cause different electrogram characteristics. We aimed to investigate whether using omnipolar maximum voltage (Vmax) map derived from high density (HD) Grid mapping catheter could assess LVZ and AF ablation outcome accurately.Fifty paroxysmal AF patients (27 males, 57.8 ± 9.5 years old) who underwent 3D mapping guided PVI were enrolled. Left atrial voltage mapping during sinus rhythm before ablation was performed. The significant LVZ (0.5 mV with area 5 cmPVI was performed in all patients, and there were 2 patients (4%) who also received additional non-PV triggers ablation. After a follow-up of 11.4 ± 5.4 months, recurrence of AF occurred in 12 patients (24%). The presence of a significant LVZ was less detected by omnipolar Vmax map, compared to HD wave map (24.0% vs. 58.0%, p = 0.001). LVZ detected by omnipolar Vmax map independently predicted the AF recurrence (odds ratio 16.91; 95% CI, 3.17-90.10; p = 0.001).LVZ detected by omnipolar Vmax map accurately predicts the AF recurrence following ablation in paroxysmal AF, compared to conventional bipolar and HD wave maps, suggesting the omnipolar Vmax map can precisely define the atrial substrate property.

BackgroundCatheter ablation (CA) is a treatment strategy for atrial fibrillation (AF) in patients with hypertrophic cardiomyopathy (HCM). We investigated the electrophysiological characteristics of recurrence in a tertiary referral center and compared long-term clinical outcomes after CA therapy with patients who did not undergo CA.MethodsPatients with HCM and AF who underwent CA (group 1, n = 60) or pharmacological treatment (group 2, n = 298) between 2006 and 2021 were enrolled in this study. The baseline characteristics and electrophysiological characteristics of group 1 patients were examined to elucidate the reason for the recurrence of AF after CA therapy. The clinical results of the patients in Group 1 and Group 2 were compared using a propensity score (PS)-matched method.ResultsThe most common cause of recurrence was pulmonary vein reconnection (86.5%), followed by non-pulmonary vein triggers (40.5%), cavotricuspid isthmus flutter (29.7%), and atypical flutter (24.3%). Thyroid disease (HR, 14.713; P P = 0.03), and non-paroxysmal AF (HR, 4.012; P = 0.01); these factors independently predicted recurrence. After the first recurrence, patients who underwent repeat CA showed a better arrhythmia-free state (74.1%) than those who underwent drug escalation therapy (29.4%, P ConclusionsPatients who underwent CA showed better clinical outcomes than those who underwent drug therapy. The main predictors of recurrence were thyroid disease, diabetes, and non-paroxysmal AF.

BackgroundPreoperative measurements of left atrium (LA) and epicardial adipose tissue (EAT) volumes in computed tomography (CT) images have been reported to be associated with an increased risk of atrial fibrillation (AF) recurrence. We aimed to design a deep learning-based workflow to provide a reliable automatic segmentation of atria, pericardium and EAT, which can facilitate future applications in AF.MethodsA total of 157 patients with AF who underwent radiofrequency catheter ablation were enrolled in this study. The 3D U-Net models of LA, right atrium (RA) and pericardium were used to develop the pipeline of total, LA-and RA-EAT automatic segmentation. We defined the attenuation range between -190 to -30 HU as fat within the pericardium to obtain total EAT. Regions between the dilated endocardial boundaries and endocardial walls of LA or RA within the pericardium were used to detect the voxels attributed to fat, resulting in LA-EAT and RA-EAT.ResultsThe LA, RA and pericardium segmentation models achieved Dice coefficients of 0.960 ± 0.010, 0.945 ± 0.013 and 0.967 ± 0.006, respectively. The 3D segmentation models correlated well with ground truth for LA, RA and pericardium (r=0.99 and p < 0.001 for all). For the results of EAT, LA-EAT and RA-EAT segmentation, Dice coefficients of our proposed method were 0.870 ± 0.027, 0.846 ± 0.057 and 0.841 ± 0.071, respectively.ConclusionsOur proposed workflow for automatic LA/RA and EAT segmentation applying 3D U-Nets on CT images was reliable in patients with AF.

Background Brugada syndrome is a major cause of sudden cardiac death in young people with a distinctive electrocardiogram (ECG) feature. We aimed to develop a deep learning-enabled ECG model for automatic screening Brugada syndrome to identify these patients at an early time, thus allowing for life-saving therapy. Methods A total of 276 ECGs with a type 1 Brugada ECG pattern (276 type 1 Brugada ECGs and another randomly retrieved 276 non-Brugada type ECGs for one to one allocation) were extracted from the hospital-based ECG database for a two-stage analysis with a deep learning model. After trained network for identifying right bundle branch block pattern, we transferred the first-stage learning to the second task to diagnose the type 1 Brugada ECG pattern. The diagnostic performance of the deep learning model was compared to that of board-certified practicing cardiologists. The model was further validated in the independent ECG dataset, collected from the hospitals in Taiwan and Japan. Results The diagnoses by the deep learning model (AUC: 0.96, sensitivity: 88.4%, specificity: 89.1%) were highly consistent with the standard diagnoses (Kappa coefficient: 0.78). However, the diagnoses by the cardiologists were significantly different from the standard diagnoses, with only moderate consistency (Kappa coefficient: 0.63). In the independent ECG cohort, the deep learning model still reached a satisfactory diagnostic performance (AUC 0.89, sensitivity: 86.0%, specificity: 90.0%). Conclusions We presented the first deep learning-enabled ECG model for diagnosing Brugada syndrome, which appears to be a robust screening tool with a diagnostic potential rivaling trained physicians.

Aims For patients with typical and atypical atrial flutter (AFL) but without history of atrial fibrillation (AF), the long-term cardiovascular (CV) outcomes after catheter ablation for AFL remain unclear. We compared the long-term all-cause mortality and CV outcomes in patients with AFL receiving catheter ablation compared with the results with medical therapy. Methods and results Atrial flutter patients receiving catheter ablation for typical AFL were identified using the Health Insurance Database, and constituted the ‘AFL ablation group’. Patients with typical and atypical AFL but without ablation (AFL without ablation group) were propensity matched to the AFL ablation group. Patients with prior AF diagnosis were excluded. Primary outcomes included all-cause and CV mortality, heart failure (HF) hospitalization, and stroke. The multivariable cox hazards regression model was used to evaluate the hazard ratio (HR) for study outcomes. A total of 3784 AFL patients (1892 patients in each group) was studied. Their mean follow-up durations were 7.85 ± 2.57 years (AFL without ablation group) and 8.31 ± 4.53 years (AFL ablation group). Atrial flutter with ablation patients had lower risks of all-cause mortality (HR: 0.68, P < 0.001), CV deaths (HR: 0.78, P = 0.001), HF hospitalization (HR: 0.84, P = 0.01), and stroke (HR: 0.80, P = 0.01). Conclusions Catheter ablation for AFL in patients without prior AF was associated with lower risks of all-cause mortality and CV events compared with AFL patients without ablation during long-term follow-ups.

Background: The presence of abnormal substrate of left atrium is a predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation. We aimed to investigate the isochronal late activation mapping to access the abnormal conduction velocity for predicting AF ablation outcome. Methods: Forty-five paroxysmal AF patients (30 males, 57.8±8.7 years old) who underwent pulmonary vein isolation were enrolled. Isochronal late activation mapping was retrospectively constructed with 2 different windows of interest: from onset of P wave to onset of QRS wave on surface electrocardiography (W1) and 74 ms tracking back from the end of P wave (W2). Deceleration zone was defined as regions with 3 isochrones (DZa) or ≥4 isochrones (DZb) within a 1 cm radius on the isochronal late activation mapping, and the estimated conduction velocity (ECV) are 0.27 m/s and Results: Pulmonary vein isolation was performed in all patients, and there were 2 patients (4.4%) received additional extrapulmonary vein ablation. After a mean follow-up of 12.7±4.5 months, recurrence of AF occurred in 14 patients (31.1%). Patients with the presence of DZb in W2 had higher AF recurrence (Kaplan-Meier event rate estimates: HR, 9.41 [95% CI, 2.61–33.90]; log-rank P Conclusions: Deceleration zone detected by isochronal late activation mapping represents a critical AF substrate, it accurately predicts the AF recurrence following ablation in patients with paroxysmal AF.

Introduction: Ventricular arrhythmia (VA) from the left ventricular summit (LVS) is a common origin of VA, which resulting LV dysfunction in some patients. However, the predictors of LV cardiomyopathy were not well-elucidated. The present study sought to investigate the risk factor of LV cardiomyopathy and the outcome in patients with LVS VA Methods: Between 2013 and 2018, a total of 139 patients (60.7% men; mean age 53.2 ± 13.9 years-old) underwent catheter ablation for LVS VA from two centers. Detailed patient demographics, electrocardiograms, electrophysiological characteristics, and clinical outcomes were extracted for analysis. LV cardiomyopathy was defined as LV ejection fraction (LVEF) Results: Acute procedural success was achieved in 92.8 % of patients. There were 40 patients (28.8%) with LV cardiomyopathy, and the mean LVEF improved from 37.5 ± 9.3% to 48.5 ± 10.2% after ablation ( p < 0.001). After multivariate analysis, the independent predictors of LV dysfunction were wider QRS duration of the VA (odds ratio [OR]1.02; 95% confidence interval [CI]: 1.00-1.04; p = 0.046) and the absolute earliest activation time discrepancy (AEAD) between epicardium and endocardium (OR 1.05; 95% confidence interval CI: 1.00-1.09; p = 0.048). After ablation, the LV function was completely recovered in 20 patients (50%). The predictors for irreclaimable LV function included wider PVC QRS duration (OR 1.09; 95% CI: 1.02-1.17; p = 0.012) and poorer LVEF (OR 0.85; 95% CI: 0.74-0.97; p = 0.020). Conclusion: In patients with VA from LVS, PVC QRS duration and AEAD predicted the deteriorating LV systolic function. Catheter ablation could reverse the LV remodeling. Narrower QRS duration and better LVEF predicted a better recovery of LV function after ablation.

Background The mechanisms underlying angiotensin receptor-neprilysin inhibitor (ARNi) suppression of ventricular arrhythmia (VA) are unclear. This study aimed to investigate the mechanism of ARNi-related suppression of VA in a heart failure (HF) model. Methods New Zealand white rabbits (n = 6 per group) were assigned to normal, HF [4 weeks of left ascending artery (LAD) ligation], angiotensin receptor blocker (ARB, valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation), and ARNi (sacubitril at 34 mg/kg/day and valsartan at 27 mg/kg/day for 3 weeks after 1 week of LAD ligation) groups. Experiments involving echocardiogram, optical mapping, histological of trichrome stain and immunostain, and flow cytometry were performed. Results HF group had larger left ventricular (LV) internal dimensions in diastole and systole, and lower LV ejection fraction and fractional shortening than normal, ARB, and ARNi groups. HF group had a prolonged action potential duration (APD) and decreased conduction velocity (CV), which was mitigated in ARB and ARNi groups. HF group had a prolonged QRS duration, QT and QTc intervals, which was reversed in ARB and ARNi groups. HF group had a steeper maximum slope of APD restitutions, which was attenuated in normal, ARB, and ARNi groups. HF group had increased number of phase singularities (PSs) and VA inducibility than normal, ARB, and ARNi groups. A higher content of fibrosis was found in HF group than that in normal, ARB, and ARNi groups. Compared to ARB group, ARNi had a lower context of fibrosis. HF group had more peripheral blood CD4+ and CD8+ cells count than normal, ARB, and ARNi group. Conclusions In a rabbit model of ischemic HF, ventricular arrhythmogenesis could be suppressed by ARNi treatment. This appears to be mediated by reversing changes in the APD, CV, maximum slope of the APDR, PSs, fibrosis, and inflammation.

The substrate and ablation outcome in arrhythmogenic right ventricular cardiomyopathy (ARVC) with or without right ventricular (RV) dysfunction is unclear.We aimed to investigate ablation outcome and substrate in ARVC patients with or without RV dysfunction.We retrospectively studied ARVC patients with (group 1) or without RV dysfunction (group 2) undergoing substrate mapping/ablation. Baseline characteristics and electrophysiological features were compared. The RV was divided into 7 prespecified segments. The scarred segment was defined as more than 50% of the area with bipolar scar. A multivariate regression analysis was performed to predict the risk of ventricular tachycardia (VT) recurrence.A total of 106 patients were enrolled (57 in group 1 and 49 in group 2). There were more men (73.7% vs 32.7%,The presence of RV dysfunction was associated with a larger abnormal substrate in the endocardium and epicardium of the RV. A scar involving the inferior portion and TV is associated with RV dysfunction. Scarring in the superior TV of the endocardium can predict recurrence despite catheter ablation.

Background Diabetes has a pronounced effect on the peripheral vasculature. The accumulation of advanced glycation end products (AGEs) is regarded as the crucial mechanism responsible for vascular damage in diabetes, but it is not easy to be avoided from food. In this study, we aimed to investigate the effects of an oral absorbent, AST-120, on the accumulation of AGEs and changes in blood flow recovery in diabetic mice. Methods The mice were divided into four groups, wild-type (WT) mice without treatment, WT mice treated with 5% AST-120 mixed into pulverized chow, streptozotocin-induced diabetes mellitus (DM) mice, and DM mice treated with 5% AST-120. Six weeks after hind-limb ischemia surgery, blood flow reperfusion, histology, plasma AGE, and cytokine were examined. Bone marrow cells were cultured and derived into macrophages to evaluate the effects of AGEs on macrophage polarization. Results Plasma AGEs were significantly increased in diabetic mice. AST-120 could bind to AGEs and reduced their plasma concentrations. Histological analysis revealed fewer collateral vessels with corresponding impairment of blood flow recovery in diabetic mice. In these mice, AGE-positive and AGE receptor-positive macrophages were numerous in ischemic limbs compared with non- diabetic mice. In diabetic mice, macrophages in ischemic tissues demonstrated greater M1 polarization than M2 polarization; this pattern was reversed in the AST-120 treatment group. The change in macrophage polarization was associated with the corresponding expression of pro-inflammatory cytokines in the ischemic tissues. In cell cultures, AGEs triggered the transformation of bone marrow-derived macrophages into the M1 phenotype. The alterations in the polarization of macrophages were reversed after treatment with AST-120. Conclusions Oral administration of AST-120 decreased the serum levels of AGEs in diabetic mice and improved neovascularization of ischemic limbs. This benefit may be due to, at least partially, the alterations in macrophage polarization and the associated changes in inflammatory cytokines.

Introduction The efficacy of stereotactic body radiation therapy (SBRT) as an alternative treatment for recurrent ventricular tachycardia (VT) is still unclear. This study aimed to report the outcome of SBRT in VT patients with nonischemic cardiomyopathy (NICM). Methods The determination of the target substrate for radiation was based on the combination of CMR results and electroanatomical mapping merged with the real-time CT scan image. Radiation therapy was performed by Flattening-filter-free (Truebeam™) system, and afterward, patients were followed-up for 13.5±2.8 months. We analyzed the outcome of death, incidence of recurrent VT, ICD shocks, anti-tachycardia pacing (ATP) sequences, and possible irradiation side-effects. Results A total of 3 cases of NICM patients with anteroseptal scar detected by CMR. SBRT was successfully performed in all patients. During the follow-up, we found that VT recurrences occurred in all patients. In one patient, it happened during a 6-week blanking period, while the others happened afterward. Re-hospitalization due to VT only appeared in one patient. Through ICD interrogation, we found that all patients have reduced VT burden and ATP therapies. All of the patients died during the follow-up period. Radiotherapy-related adverse events did not occur in all patients. Conclusions SBRT therapy reduces the number of VT burden and ATP sequence therapy in NICM patients with VT, which had a failed previous catheter ablation. However, the efficacy and safety aspects, especially in NICM cases, remained unclear. This article is protected by copyright. All rights reserved.

IntroductionUnsuccessful endocardial ablation for perimitral atrial flutter (AFL) could be attributed by the epicardial bridging.ObjectiveThis study aimed to investigate the electrophysiological characteristics of epicardial breakthrough during catheter ablation of perimitral AFL.Materials and methodsThis retrospective study recruited 40 patients who received successful catheter ablation of perimitral AFL from January 2016 to June 2021. The patients were divided into two groups: group 1 (n = 18) successful endocardial ablation, and group 2 (n = 22) successful epicardial ablation following unsuccessful endocardial ablation owing to incomplete mitral block or unachievable termination AFL. The local electrogram (EGM) interval of coronary sinus (CS) duration perimitral AFL was measured before catheter ablation.ResultsThere was no significant difference in the baseline characteristics between the two groups. In group 2, 60% of successful epicardial ablation was performed in intra-CS ablation and 40% in VOM ethanol infusion. Group 2 patients had a longer EGM interval of distal CS than that in group 1 (CS1-2: 64.2 17.5 vs. 42.4 0.09 ms, P = 0.008, CS3-4: 57.13 19.4 vs. 43.8 7.5 ms; P = 0.001). The conduction velocity at successful site was slower in group 2 compared to group 1 (0.18 0.05 vs. 0.75 0.19 m/s, P = 0.040). In the multivariate analysis, distal EGM interval (CS1-2) was identified as independent predictor of the need of epicardial ablation with the optimal cutoff of 49 ms.ConclusionLonger EGM interval in distal CS during perimitral AFL was observed in perimitral AFL patients with epicardial breakthrough following endocardial-failed ablation, which may be associated with the need of epicardial ablation.

Catheter ablation for tachyarrhythmia via superior approach has been used in patients without possible inferior vena cava access such as in cases of venous occlusion or complex anomaly. Difficulty in catheter manipulation, instability, number of required vascular access, and radiation exposure of operator had been described in the procedure. Application of three-dimensional (3-D) mapping system in catheter ablation via superior approach could navigate the guiding catheter and provide more precise ablation. We reported four cases receiving catheter ablation due to atrioventricular nodal reentry tachycardia, atrial fibrillation and right ventricular arrhythmia via superior approach facilitated by 3-D mapping system with fewer vascular access and catheters.

Catheter ablation is a current therapeutic approach for atrial fibrillation (AF). However, its efficacy for long-standing persistent AF remains suboptimal.The purpose of this study was to test the hypothesis that a panoramic mapping system (CARTOFINDER, Biosense Webster) can guide pulmonary vein (PV) isolation and additional potential AF drivers.A total of 76 patients with nonparoxysmal AF referred for ablation guided by a novel high-density panoramic mapping system with CARTOFINDER were prospectively enrolled. Of this cohort, 40 patients (52.6%) had long-standing persistent AF (CARTOFINDER group). We then retrospectively screened the patients with long-standing persistent AF undergoing conventional PV isolation and elimination of non-PV triggers during the contemporary period (conventional group). They were matched at a 1:2 ratio (40 patients in group 1 received ablation guided by CARTOFINDER; 80 patients in group 2 receiving conventional PV isolation and elimination of non-PV triggers).During follow-up, patients in group 1 had a lower recurrence AF rate than those in group 2 (Identification of the potential drivers in long-standing AF is crucial. Compared with conventional PV isolation and elimination of non-PV triggers, ablation guided by a high-density panoramic mapping system (CARTOFINDER) might have a better outcome in patients with long-standing persistent AF.

Autonomic system plays a pivotal role in the pathogenesis of paroxysmal atrial fibrillation (AF). Skin sympathetic nerve activity (SKNA) is a noninvasive tool for assessing sympathetic tone. However, data on changes in SKNA after ablation are limited. Here, we retrospectively enrolled 37 patients with symptomatic drug-refractory paroxysmal AF who underwent pulmonary vein isolation (PVI) with radiofrequency ablation (RFA) or cryoablation (CBA). SKNA was measured from the chest and right arm 1 day prior to ablation, as well as 1 day and 3 months after ablation. One day after ablation, the SKNA-Arm increased from 517.1 µV (first and third quartiles, 396.0 and 728.0, respectively) to 1226.2 µV (first and third quartiles, 555.2 and 2281.0), with an increase of 179.8% (125% and 376.0%) (p < 0.001); the SKNA-Chest increased from 538.2 µV (first and third quartiles, 432.9 and 663.9) to 640.0 µV (first and third quartiles, 474.2 and 925.6), with an increase of 108.3% (95.6% and 167.9%) (p = 0.004), respectively. In those without recurrence, there was a significant increase in SKNA 1 day after ablation as compared with those before ablation. Twelve patients received SKNA measurement 3 months after ablation; both SKNA-Arm (p = 0.31) and SKNA-Chest (p = 0.27) were similar to those before ablation, respectively. Among patients with symptomatic drug-refractory paroxysmal AF receiving PVI, increased SKNA was observed 1 day after ablation and returned to the baseline 3 months after ablation. Elevation of SKNA was associated with lower early and late recurrences following ablation.

Introduction A drug provocation test (DPT) is important for the diagnosis of Brugada syndrome (BrS). The link, however, between dynamic changes of ECG features after DPT and unstable ventricular arrhythmia (VA) in BrS remains unknown. Methods Between 2014 and 2019, we assessed 27 patients with BrS (median age: 37.0 [interquartile range, IQR: 22.0-51.0] years; 25 men], including 9 (33.3%) with a history of unstable VA and 18 (66.7%) without. All patients in the study presented with Brugada-like ECG features before DPT. The ECG parameters and dynamic changes (∆) in 12-lead ECGs recorded from the 2nd , 3rd , and 4th intercostal spaces (ICS) before and at 1, 6, 12, 18, 24 hours after DPT (oral flecainide 400 mg) were analyzed. Results The total amplitude of V1 at the 3rd ICS 18 and 24 hours after DPT was significantly lower in patients with history of unstable VA than in those without. Patients with BrS and unstable VAs had a significantly larger ∆ amplitude of V1 at the 2nd ICS 12 hours after DPT than in those without unstable VAs (0.28[0.18-0.41] mV vs. 0.08[0.01-0.15] mV, p=0.01). A multivariate analysis revealed that the amplitude of V1 at the 3rd ICS 18 and 24 hours after DPT and the ∆ amplitude of V1 at the 2nd ICS 12 hours after DPT were associated with history of unstable VA. Conclusion Nonuniform changes and spatiotemporal differences in precordial ECG features after DPT were observed in patients with BrS and these may be surrogate markers for risk stratification. This article is protected by copyright. All rights reserved.

Resistin is an adipocytokine that is abundantly secreted from lipid cells and is related to the inflammatory process and cardiometabolic diseases. This study aimed to examine the role of resistin on inflammation and its effect on the clinical outcome of patients with atrial fibrillation (AF) following catheter ablation.A total of 108 patients (56.9 ± 12.0 years, 76.8% male) with symptomatic and drug-refractory AF undergoing catheter ablation were enrolled. Inflammatory biomarkers and epicardial fat volume by contrast computed tomography (CT) images were assessed in all patients before the procedure. Baseline resistin correlated with epicardial fat volume, tumor necrosis factor-α (TNF-α), and left atrial (LA) scar area. After the index procedure, the univariate analysis revealed that hypertension, persistent AF, LA diameter, and plasma resistin level were related to recurrent atrial arrhythmia. Multivariate regression analysis revealed that persistent AF, LA diameter, and plasma resistin level all independently predicted recurrent atrial arrhythmia after ablation. Plasma resistin with a level higher than 777 (pg/mL) could predict recurrence following catheter ablation of AF.High plasma resistin level is associated with poor left atrial substrate, high epicardial fat volume, and elevated TNF-α level in patients with AF. Plasma resistin may predict the recurrence of atrial arrhythmia after ablation.

INTRODUCTION Accurate identification of slow conducting regions in patients with scar-related atrial tachycardia (AT) is difficult using conventional electrogram annotation for cardiac electroanatomic mapping (EAM). Estimating delays between neighboring mapping sites is a potential option for activation map computation. We describe our initial experience with CARTO 3 Coherent Mapping (Biosense Webster Inc,) in the ablation of complex ATs. METHODS Twenty patients (58 ± 10 y/o, 15 males) with complex ATs were included. We created three-dimensional EAMs using CARTO 3 system with CONFIDENSE and a high-resolution mapping catheter (Biosense Webster Inc). Local activation time and coherent maps were used to aid in the identification of conduction isthmus (CI) and focal origin sites. System-defined slow or nonconducting zones and CI, defined by concealed entrainment (postpacing interval

Identification of sinus node dysfunction (SND) before termination of persistent AFL by catheter ablation (CA) is challenging. This study aimed to investigate the characteristics and predictors of acute and delayed SND after AFL ablation. We retrospectively enrolled 221 patients undergoing CA of persistent AFL in a tertiary referral center. Patients with SND who required a temporary pacemaker (TPM) after termination of AFL or a permanent pacemaker (PPM) during follow-up were identified. Acute SND requiring a TPM was found in 14 of 221 (6.3%) patients following successful termination of AFL. A total of 10 of the 14 patients (71.4%) recovered from acute SND. An additional 11 (5%) patients presenting with delayed SND required a PPM during follow-up, including 4 patients recovering from acute SND. Of these, 9 of these 11 patients (81.8%) underwent PPM implantation within 1 year after the ablation. In multivariable analysis, female gender and a history of hypothyroidism were associated with the requirement for a TPM following termination of persistent AFL, while older age and a history of hypothyroidism predicted PPM implantation. This study concluded that the majority of patients with acute SND still require a PPM implantation despite the initial improvement. Therefore, it is reasonable to monitor the patients closely for at least one year after AFL ablation.

The comprehensive surveillance for interval changes in signal-averaged P-wave (SAPW) after pulmonary vein isolation (PVI) remains lacking. We aimed to analyze the SAPW parameters before and after PVI and explored their link to the left atrial electrical properties.Eighteen patients with paroxysmal atrial fibrillation receiving primary catheter ablation were enrolled. SAPW parameters, including root mean square voltages in the last 40, 30, and 20 ms (RMS40, RMS30, and RMS20, respectively), the total P-wave (RMSt), the integral of P-wave potentials (Int-p), and P-wave duration (fPWD), were measured before and after PVI and correlated to the left atrial activation time (LAT) and mean left atrial voltage (LAV) from electro-anatomical mapping.Compared with the SAPW before PVI, fPWD (before vs after PVI: 144.1 ± 5.2 vs 135.1 ± 11.9 ms, p = 0.02), Int-p (687.4 ± 173.1 vs 559 ± 202.5 mVms, p = 0.01), and RMSt (6.44 ± 1.3 vs 5.44 ± 2.0 mV, p = 0.04) all decreased after PVI. RMS20, RMS30, and RMS40 showed no significant difference. Similarly, LAT (97.5 ± 9.3 vs 90.5 ± 9.3 ms, p = 0.008) and LAV (1.37 ± 0.27 vs 0.96 ± 0.31 mV, p = 0.001) decreased after PVI. Although consistent changes after PVI were observed between SAPW parameters and LAT or LAV, no linear correlation was observed among them.The consistent changes in SAPW and left atrial electrical properties after PVI suggest that SAPW may be used as a noninvasive tool to monitor the responses to PVI.

BackgroundCoronary artery disease (CAD) is one of the leading causes of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM), who are at a greater risk of acute myocardial infarction (AMI) and sudden cardiac death. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to reduce cardiovascular events and mortality in T2DM patients with a risk of cardiovascular disease. This study aimed to investigate the effect of SGLT2 inhibitor use on the adverse cardiovascular and renal outcomes in T2DM patients with AMI.MethodsA total of 1,268 patients admitted to the Coronary Care Unit due to AMI were retrospectively screened.Patients taking SGLT2 inhibitors before or during the index AMI hospitalization were assigned as group 1. Patients who never received SGLT2 inhibitors were assigned as group 2. Patients in groups 1 and 2 were matched in a 1:2 ratio, and 198 T2DM patients with stabilized AMI were retrospectively enrolled for the final analysis.ResultsWith a mean follow-up period of 23.5 ± 15.7 months, 3 (4.5%) patients in group 1 and 22 (16.7%) patients in group 2 experienced rehospitalization for acute coronary syndrome (ACS), while 1 (1.5%) patient in group 1 and 7 (5.3%) patients in group 2 suffered sudden cardiac death. The Kaplan–Meier curves demonstrated that the patients in group 1 had a lower risk of adverse cardiovascular outcomes. According to the multivariate analysis, the baseline estimated glomerular filtration rate (eGFR) (P = 0.008, 95% CI: 0.944–0.991) and the use of SGLT2 inhibitors (P = 0.039, 95% CI: 0.116–0.947) were both independent predictors of adverse cardiovascular outcomes. On the other hand, the use of SGLT2 inhibitors was not associated with adverse renal outcomes.ConclusionIn T2DM patients with stabilized AMI, the use of SGLT2 inhibitors was associated with a lower risk of adverse cardiovascular outcomes. In addition, the baseline renal function was also an independent predictor of adverse cardiovascular outcomes.

Background Amiodarone is commonly used during therapeutic hypothermia (TH) following cardiac arrest due to ventricular arrhythmias. However, electrophysiological changes and proarrhythmic risk after amiodarone treatment have not yet been explored in TH. Methods Epicardial high-density bi-ventricular mapping was performed in pigs under baseline temperature (BT), TH (32–34°C), and amiodarone treatment during TH. The total activation time (TAT), conduction velocity (CV), local electrogram (LE) duration, and wavefront propagation from pre-specified segments were analyzed during sinus rhythm (SR) or right ventricular (RV) pacing (RVP), along with tissue expression of connexin 43. The vulnerability to ventricular arrhythmias was assessed. Results Compared to BT, TH increased the global TAT, decreased the CV, and generated heterogeneous electrical substrate during SR and RVP. During TH, the CV reduction and LE duration prolongation were greater in the anterior mid RV than in the other areas, which changed the wavefront propagation in all animals. Compared to TH alone, amiodarone treatment during TH further increased the TAT and LE duration and decreased the CV. Heterogeneous conduction was partially attenuated after amiodarone treatment. After TH and amiodarone treatment, the connexin 43 expression in the anterior mid RV was lower than that in the other areas, compatible with the heterogeneous CV reduction. The animals under TH and amiodarone treatment had a higher incidence of inducible ventricular arrhythmias than those under BT or TH without amiodarone. Conclusion Electrical heterogeneity during amiodarone treatment and TH was associated with vulnerability to ventricular arrhythmias.

Dynamic display of real-time wavefront activation pattern may facilitate the recognition of reentrant circuits, particularly the diastolic path of ventricular tachycardia (VT).We aimed to evaluate the feasibility of LiveView Dynamic Display for mapping the critical isthmus of scar-related reentrant VT.Patients with mappable scar-related reentrant VT were selected. The characteristics of the underlying substrates and VT circuits were assessed using HD grid multielectrode catheter. The VT isthmuses were identified based on the activation map, entrainment, and ablation results. The accuracy of the LiveView findings in detecting potential VT isthmus was assessed.We studied 18 scar-related reentrant VTs in 10 patients (median age: 59.5 years, 100% male) including 6 and 4 patients with ischemic and nonischemic cardiomyopathy, respectively. The median VT cycle length was 426 ms (interquartile range: 386-466 ms). Among 590 regional mapping displays, 92.0% of the VT isthmus sites were identified by LiveView Dynamic Display. The accuracy of LiveView for isthmus identification was 84%, with positive and negative predictive values of 54.8% and 97.8%, respectively. The area with abnormal electrograms was negatively correlated with the accuracy of LiveView Dynamic Display (r = -.506, p = .027). The median time interval to identify a VT isthmus using LiveView was significantly shorter than that using conventional activation maps (50.5 [29.8-120] vs. 219 [157.5-400.8] s, p = .015).This study demonstrated the feasibility of LiveView Dynamic Display in identifying the critical isthmus of scar-related VT with modest accuracy.

The identification of post pulmonary vein isolation (PVI) gaps by activation and voltage maps is time-consuming. This study aimed to investigate the characteristics, efficiency and accuracy of LiveView dynamic display module (EnSite™ Dynamic Display; Abbott, Abbott Park, IL, USA) in unmasking post PVI gaps and conduction block line.Twenty four patients with paroxysmal atrial fibrillation (PAF) who failed to achieve first-pass PVI or with recurrent PAF were enrolled. Ninety-six pulmonary veins (PVs) were evaluated, and gaps were identified in 25 (26.0%) PVs. The gap location was confirmed by activation and propagation maps; 110 frames on gaps and 118 frames on block lines were analyzed by using LiveView module. We defined isochronal crowding in the local activation time (LAT) mode as three colors between two adjacent electrodes. Each frame was classified as with or without isochronal crowding in LAT mode and one/continuous color or isochronal discontinuity in reentrant mode. The gray color inside the PVs was considered to represent conduction block.The isochronal crowding could be found on both gap and block line in LAT mode, whereas isochronal discontinuity only presented on the block line in reentrant mode. The sensitivity and specificity of isochronal discontinuity or gray color in reentrant mode to identify block line were 61.0% and 100%, respectively. The sensitivity and specificity of isochronal crowding or gray color in LAT mode to identify block line were 71.2% and 71.8%, respectively.Reentrant mode in LiveView module is very specific in identifying block lines. We proposed an efficient, practical algorithm to differentiate the block line from PV gaps.

BACKGROUND: The presence of ventricular tachycardia (VT) is associated with higher mortality. The annual incidence of VT after a diagnosis of amyloidosis and the associated cardiovascular (CV) outcomes have not been well assessed in a large cohort. METHODS: A total of 12,139 amyloidosis patients were identified from the Taiwan National Health Insurance Research Database. Non-amyloidosis group was matched 1:1 for age, gender, hypertension, and diabetes mellitus (DM) to the amyloidosis group using a propensity score. Analysis of the risk of CV outcomes was conducted. We also analyzed the incidence of cardiac amyloidosis (CA). RESULTS: The incidence rates of amyloidosis and CA were 6.54 and 0.61 per 100,000 person-years, respectively. Multivariable analysis revealed that the risk of VT was higher in both the amyloidosis [hazard ratio (HR): 7.90; 95% confidence interval (CI): 4.49-13.9] and CA (HR: 153.3, 95% CI: 54.3-432.7) groups. In the amyloidosis group, the risk of heart failure (HF)-related hospitalization, CV death, and all-cause death was also higher. Amyloidosis was associated with a higher CV mortality rate following VT (HR: 1.50; 95% CI: 1.07-2.12). The onset of a new VT event in patients with amyloidosis was associated with HF, DM, chronic liver disease, and anti-arrhythmic drug use. CONCLUSIONS: In this nationwide cohort study, the incidence rates of amyloidosis and CA were 6.54 and 0.61 per 100,000 person-years, respectively. The long-term risks of VT and CV mortality were higher in the patients with amyloidosis and CA. The patients with amyloidosis had a poorer prognosis following VT events, highlighting the importance of continuous monitoring in these patients.

Catheter ablation provides a therapeutic option for decreasing episodes of ventricular tachycardia in patients with coronary artery disease. Clinical studies show improvement with catheter ablation in reducing arrhythmia recurrence and therapy from implantable defibrillators, but not in decreasing mortality. Ablation can be an important tool for patients with electrical storm. Overall, complication rates of catheter ablation are acceptable, but recurrence rates are still significant. Advances in mapping and ablation technologies could be expected to improve the success rates and reduce the mortality.