bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endocardial vs endo-epicardial ablation of ventricular arrhythmia in arrhythmogenic right ventricular cardiomyopathy: a single center experience
Authors: Simonova K.A , Kamenev A.V , Tatarskiy R.B , Naymushin M.A , Orshanskaya V.S , Lebedeva V.K , Garkina S.V , Vander M.A , Vakhrushev A.D , Lebedev D.S , Mikhaylov E.N 
Published: November 2020

Abstract

Background
The majority of patients have a sub-epicardial scar as a substrate for VT episodes.

Purpose
We sought to compare the efficacy of endocardial (ENDO) and epicardial (EPI) substrate modification in patients with ARVC.

Methods
20 consecutive ARVC patients (mean age 41,4±13,8, 70% males; ICD previously implanted in 10 patients) with indications to ventricular arrhythmia ablation (RFA) were included into a prospective observational study. The EPI group consisted of 10 patients with sustained ventricular tachycardia (VT) (definite diagnosis ARVC – 8 patients; borderline – 1, possible – 1) who signed an informed consent to epicardial access. The ENDO group included 10 patients (definite diagnosis ARVC – 9 patients), five of them demonstrated sustained VT and 5 patients had frequent symptomatic premature ventricular contractions (PVC). Epicardial access in the EPI group was obtained through subxyphoid puncture. Bi- and unipolar voltage mapping of endocardial and epicardial surfaces was performed. Maps were evaluated for the presence of local abnormal ventricular electrical activity (LAVA, low-voltage areas and sites with highly fractionated or late activity). Ablation was performed at sites of LAVA on either side of the ventricular wall. In the ENDO group endocardial only ablation at LAVA sites was performed. RF energy ablation was 40W at the epicardial surface and 40–50W at the endocardial surface.

Results
In the EPI group endocardially mapped area of unipolar endocardial low voltage zone (LVZ) significantly prevailed over bipolar endocardial area of LVZ: 75.4 cm2 [IQR: 23.2; 211.9] vs 6.7 cm2 [IQR: 4.4; 35.5](P=0.009). Epicardial bipolar LVZ area prevailed over unipolar epicardial LVZ area: 65.3 cm2 [IQR: 55.6; 91.3] vs 6.7 cm2 [IQR: 4.4; 35.3] (P=0.005). Endocardial unipolar LVZ area in the EPI group was larger than in the ENDO group (P&gt;0,05). After ablation non-inducibility of any ventricular arrhythmia was achieved in 90% of patients in the EPI group and in 80% of cases in the ENDO group. During a mean follow-up period of 22.3±10.5 months freedom of ventricular arrhythmia recurrence was 70% in the EPI group and 100% in the control group.

Conclusions
Although epicardial area of abnormal potentials significantly prevails over endocardial area, endocardial unipolar mapping and higher RF ablation power allow performing successful ventricular arrhythmia treatment in the majority of ARVC patients.

Funding Acknowledgement
Type of funding source: None
Sustained ventricular tachycardia of left, right or both bundle branch block morphology in patients with Arrhythmogenic Cardiomyopathy
Authors: Milman A , Laredo M , Roudijk R , Peretto G , Andorin A , Sellal J.M , Duru F , Arbelo E , Lacroix D , Maury P , Peichl P , Fauchier L , Miles C , Zehavi G , Belhassen B 
Published: November 2020

Abstract

Aims
In arrhythmogenic cardiomyopathy (ACM) sustained monomorphic ventricular tachycardia (VT) typically displays left bundle branch block (LBBB) morphology. Sustained VT with right bundle branch block (RBBB) morphology is very rare despite the frequent left ventricular involvement. The present study sought to assess the prevalence of spontaneous sustained LBBB-VT, RBBB-VT or both as well as clinical and genetic differences associated with these VT types.

Methods and results
Twenty-six centers from 11 European countries provided information on 952 patients with ACM and &gt;1 episode of sustained VT observed during the patients' clinical course. VT was classified as: LBBB-VT; RBBB-VT or LBBB+RBBB-VT.
Among 952 patients, 881 (92.5%) had LBBB-VT alone, 71 (7.5%) had RBBB-VT [alone in 42 (4.4%) patients or with LBBB-VT in 29 (3.0%) patients]. Male prevalence was 90.5%, 79.2% and 55.9% in the RBBB-VT, LBBB-VT and LBBB+RBBB-VT groups, respectively (P=0.001). Patients' age at first VT did not differ amongst the 3 VT groups. ICD implantation was more frequent for the RBBB-VT and the LBBB+RBBB groups (≈90% each) vs. 67.9% for the LBBB-VT group (P=0.001). Death incidence (9.5%–17.2%) was not significantly different between the 3 groups (P=0.425). Plakophylin-2 mutations predominated in the LBBB-VT and LBBB-VT+RBBB-VT groups (47.2% and 27.3%, respectively) and Desmoplakin mutations in the RBBB-VT group (36.7%).

Conclusion
This large European survey demonstrates: 1) Sustained RBBB-VT is documented in 7.5% patients with ACM; 2) Males markedly predominate in the RBBB-VT and LBBB-VT groups but not in the LBBB+RBBB VT group; 3) Distribution of desmosomal mutations appears to be different in the 3 VT groups.

Funding Acknowledgement
Type of funding source: None
Toll-like receptor 9 is a novel therapeutic target to prevent atrial fibrillation
Authors: Soeki T , Matsumoto K , Fukuda D , Uematsu E , Matsuura T , Tobiume T , Kusunose K , Ise T , Yamaguchi K , Yagi S , Yamada H , Wakatsuki T , Sata M 
Published: November 2020

Abstract

Background
Atrial fibrillation (AF) is the most common type of arrhythmia seen in clinical practice. Recent studies suggest that inflammation contributes to the pathogenesis of AF. On the other hand, several evidence suggests that toll-like receptor (TLR) 9 recognizes bacterial DNA, activating innate immunity, whereas it also provokes inflammation in response to fragmented DNA released from mammalian cells. Recently, we have reported that TLR 9 plays a pivotal role in the development of vascular inflammation and atherogenesis through proinflammatory activation of macrophages.

Purpose
This study aimed to assess whether TLR9 contributes to the AF arrhythmogenesis.

Methods
TLR9 deficient (TLR9−/−) and wild-type mice were infused with angiotensin II (Ang II) or vehicle via an osmotic minipump for 4 weeks. Blood pressure and body weight were measured serially. Then, we examined AF inducibility by intracardiac electrophysiological study and the inflammation-induced atrial remodeling by biochemical analysis after 4 weeks of Ang II infusion.

Results
There was no significant difference in blood pressure and pulse rate between TLR9−/− and wild-type mice both before and after Ang II infusion. Ang II-treated TLR9−/− mice showed lower incidence of AF compared with wild-type mice treated with Ang II. Genetic deletion of TLR9 significantly reduced the interstitial fibrosis in atrium of Ang II-treated mice. TLR9−/− mice also showed less mRNA expressions of inflammatory and fibrosis-related biomarkers (TNF-α, interleukin-6, TGF-β, collagen-1, collagen-3) in atrium compared with wild-type mice.

Conclusions
TLR9 might contribute to the AF arrhythmogenesis associated with atrial inflammation. TLR9 might serve as a potential therapeutic target for AF.

Funding Acknowledgement
Type of funding source: None
Genetic susceptibility, elevated blood pressure and risk of atrial fibrillation
Authors: Nazarzadeh M , Pinho-Gomes A , Bidel Z , Canoy D , Dehghan A , Smith Byrne K , Bennett D , Davey Smith G , Rahimi K 
Published: November 2020

Abstract

Background
Whether elevated blood pressure (BP) is a modifiable risk factor for atrial fibrillation (AF) is not established.

Purpose
We tested (1) whether the association between BP and risk of AF is causal, (2) whether it varies according to individual's genetic susceptibility for AF, and (3) the extent to which specific BP-lowering drugs are expected to reduce this risk.

Methods
First, causality of association was assessed through two-sample Mendelian Randomization (MR), using data from two independent genome-wide association studies that included a total of one million European population. Second, UK Biobank individual participant data of 329,237 participants at baseline was used to study the effect of BP on AF according to genetic susceptibility of developing AF. Third, a possible treatment effect with BP-lowering drug classes on AF risk was predicted through genetic variants in druggable genes that code proteins related to the function of each drug class. Estimated drug effects were compared with effects on incident coronary heart disease, for which direct trial evidence exists.

Results
The two-sample MR analysis indicated that on average each 10-mm Hg increment in systolic BP increased the risk of AF (odds ratio [OR]: 1.23 [1.11 to 1.36]). This association was replicated in the UK biobank using individual participant data. However, in a further genetic risk-stratified analysis, there was evidence for a linear gradient in the relative effects of systolic BP on AF; while there was no conclusive evidence of an effect in those with low genetic risk, a strong effect was observed among those with high genetic susceptibility for AF (Figure). The indirect comparison of predicted treatment effects using genetic proxies for three main drug classes (angiotensin-converting enzyme inhibitors, beta-blockers and calcium channel blockers) suggested similar average effects for prevention of atrial fibrillation and coronary heart disease.

Conclusions
The association between elevated BP and higher risk of AF is likely to be causal, suggesting that BP-lowering treatment may be effective in AF prevention. However, average effects masked clinically important variations, with a more pronounced effect in individuals with high genetic susceptibility.
Figure 1

Funding Acknowledgement
Type of funding source: Foundation. Main funding source(s): British Heart Foundation
Levels of platelet derived extracellular vesicles in the left atrial appendage are higher in patients with permanent atrial fibrillation
Authors: Zietzer A , Al-Kassou B , Jamme P , Steffen E , Werner N , Nickenig G , Jansen F 
Published: November 2020

Abstract

Introduction
Atrial fibrillation (AF) is a frequent arrhythmic disease and one of the most important causes of thrombembolic disease due to intracardiac thrombus formation. The left atrial appendage has been identified as the structure, where thrombus formation typically takes place in AF patients. Previous studies have shown thrombus formation is more frequent in permanent, than in paroxysmal or persistent AF. Underlying causes for this finding, however, remain unclear. Recently, it has been shown, that large extracellular vesicles (Microvesicles, MVs) are mediators of platelet activation. The aim of this study is therefore to investigate if the AF subtype correlates with the regional abundance of platelet derived MVs in the left atrial appendage.

Methods and results
In order to address this question blood samples from 59 consecutive patients undergoing left and right atrial catheterization were collected from the right atrium (RA), the left atrium (LA) and the left atrial appendage (LAA). 49% of the patients had permanent AF, 34% had non-permanent AF and 17% had no history of AF. MVs were isolated from 150 μL citrate plasma by a four-step differential centrifugation protocol (20000g x 40 min as main pelleting step). The MVs were characterized by immunoblotting and nanoparticle tracking analysis. The size of the MVs ranged between 50 and 600 nm and the MVs were shown to carry typical markers such as Annexin V. For flowcytometric analysis and quantification, Calcein AM was used to identify vesicles and CD31-PE, CD41-APC, CD235a-PE-Cy7 were applied to differentiate between platelet-derived MVs (PMVs, CD41+ CD31+), endothelial cell-derived MVs (EMVs, CD41- CD31+) and Red blood cell-derived MVs (RMVs, CD235a+). Fluorescence minus one controls, a concentration row and detergent mediated degradation were used to confirm specific staining of MVs. Total MV numbers (Calcein + events) did not differ significantly between the three cardiac localizations. In the left atrial appendage, the proportion of PMV was significantly higher in permanent AF patients compared to non-permanent AF. EMV numbers only differed in the right atrium, where permanent AF patients exhibited significantly lower numbers of EMVs compared to no AF controls. No differences between the groups were detected for RMV.

Conclusion
In the present study, we found that PMV levels in the left atrial appendage correlate with the type of atrial fibrillation (permanent vs non-permanent). PMVs have been connected to platelet activation and thrombus formation. These results may help to better understand how different types of atrial fibrillation cause different rates of thrombus formation in the LAA.
PMV and EMV numbers by AF subtype

Funding Acknowledgement
Type of funding source: Public Institution(s). Main funding source(s): Medical Faculty University Bonn
Prevalence of atrial arrhythmia in patients with arrhythmogenic right ventricular cardiomyopathy: a systematic review and meta-analysis
Authors: Rujirachun P , Wattanachayakul P , Charoenngam N , Winijkul A , Ungprasert P 
Published: November 2020

Abstract

Background and objectives
Little is known about atrial involvement in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Recent studies have suggested that atrial arrhythmia (AA), including atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT), was common among these patients although the reported prevalence varied considerably across the studies.

Methods
We searched for published articles indexed in MEDLINE and EMBASE databases from inception through Sep 22, 2019 to identify cohort studies of patients with ARVC that described the prevalence of atrial arrhythmia among the participants. The pooled prevalence across studies was calculated.

Results
A total of 16 cohort studies with 1,986 patients with ARVC were included into this meta-analysis. The pooled prevalence of overall AA among patients with ARVC was 17.9% (95% CI, 13.0%–24.0%; I2 88%), the pooled prevalence of AF of 12.9% (95% CI, 9.6%–17.0%; I2 78%), the pooled prevalence of AFL of 5.9% (95% CI, 3.7%–9.2%; I2 70%), and the pooled prevalence of AT of 7.1% (95% CI, 3.7%–13.0%; I2 49%).

Conclusions
AA is common among patient with ARVC with the pooled prevalence of approximately 18%, which is substantially higher than the reported prevalence of AA in general population.

Funding Acknowledgement
Type of funding source: None
Left ventricular stiffness assessed by diastolic wall strain predicts asymptomatic atrial high rate episodes in patients with pacemaker implantation
Authors: Kishima H , Mine T , Fukuhara E , Ishihara M 
Published: November 2020

Abstract

Background
Asymptomatic atrial fibrillation has been reported to be associated with an increased risk of embolism.

Purpose
We investigated whether the left ventricular (LV) stiffness assessed by diastolic wall strain (DWS) predicts atrial high rate episodes (AHREs) in patients with pacemaker implantation (PMI).

Methods
One hundred forty seven patients (76 males, 75.2±8.9 years, 62 with sick sinus syndrome; SSS and 85 with atrioventricular block) who did not show atrial tachyarrhythmia before PMI were studied. DWS and other measurements were assessed using transthoracic echocardiography before DDD-pacemaker implantation. DWS was calculated from the M-mode echocardiographic measurement of the LV posterior wall thickness at end-systole (PWs) and end-diastole (PWd), and DWS was defined as (PWs-PWd)/PWs.

Results
AHREs (&gt;5 min and &gt;180 beats/min) were detected in 50/147 patients during follow-up periods (38.3±13.8 months). Patients with AHREs showed reduced DWS (0.29±0.07 vs. 0.39±0.06, p&lt;0.0001), larger left atrial volume index, elevated E/e' ratio, thicker LV PWd, higher prevalence of SSS, and left bundle branch block pattern during ventricular pacing. On multivariate analysis, DWS was only independently associated with AHREs (p&lt;0.0001, HR 1.987 for each 0.1 decrease in DWS, 95% CI 1.553–2.650). Patients with reduced DWS (&lt;0.33) had a higher risk of incidences of AHREs (Figure 1).

Conclusions
LV stiffness assessed by DWS predicts AHREs in patients with PMI.
Figure 1

Funding Acknowledgement
Type of funding source: None
Amiodarone use in elderly atrial fibrillation patients with preserved ejection fraction is associated with increased short-term mortality
Authors: Li W , Tiwari N 
Published: November 2020

Abstract

Background
Amiodarone is commonly used in atrial fibrillation (AF). Long-term use of amiodarone is associated with significant toxicities, especially in elderly patients. However, in the short term after hospitalization of AF, it remains uncertain whether the use of amiodarone will increase mortality.

Methods
We conducted a retrospective cohort study including patients (Age≥60 years old) who were hospitalized between 07/01/2004 and 06/30/2019 with a primary diagnosis of AF and left ventricular ejection fraction (LVEF) ≥50%. Patients who were prescribed amiodarone during hospitalization but not before are considered as amiodarone group (348 patients). Patients who weren't prescribed amiodarone are considered as non-amiodarone group (2260 patients).
Univariate analysis solely analyzed amiodarone use on the all-cause mortality (Kaplan-Meier Curve), and possible confounders were adjusted in the multivariate analysis including age, gender, diabetes mellitus (DM), hypertension (HTN), coronary artery disease (CAD), as well as LVEF, left atrium internal diameter, use of other rate control medications (e.g. beta-blocker). The proportional-hazard assumption was tested by Log-rank test and a 2-sided P value of &lt;0.05 is considered statistically significant. The hazard ratio and 95% confidence interval (CI) were calculated.

Results
Patients' baseline characteristics were listed in Table 1. Both Univariate and Multivariate analysis showed amiodarone group had higher in-hospital (hazard ratio 2.06; p=0.036) and 100-day mortality (hazard ratio 1.86; p=0.028). Other rate control medication use was also associated with increased mortality but not statistically significant. The results are showed in Figure 1.

Conclusion
Amiodarone use in elderly patients with preserved ejection fraction is associated with increased short-term all-cause mortality after hospitalization of AF.
Figure 1. KM Curve & ForestPlot of Mortality

Funding Acknowledgement
Type of funding source: None
Outcome of contact force-guided radiofrequency catheter ablation or second generation cryoballoon ablation for paroxysmal atrial fibrillation: propensity score matched analysis
Authors: Ukita K , Kawamura A , Nakamura H , Yasumoto K , Tsuda M , Okamoto N , Tanaka A , Matsunaga Y , Yano M , Egami Y , Shutta R , Nishino M , Tanouchi J 
Published: November 2020

Abstract

Background
Little has been reported on the outcome of contact force (CF)-guided radiofrequency catheter ablation (RFCA) and second generation cryoballoon ablation (CBA).

Purpose
The purpose of this study was to compare the outcome of CF-guided RFCA and second generation CBA for paroxysmal atrial fibrillation (PAF).

Methods
We enrolled the consecutive 364 patients with PAF who underwent initial ablation between September 2014 and July 2018 in our hospital. We compared the late recurrence of atrial tachyarrhythmia more than three months after ablation between RFCA group and CBA group. All RFCA procedures were performed using CF-sensing catheter and all CBA procedures were performed using second generation CB.

Results
There were significant differences in background characteristics: chronic kidney disease, serum brain natriuretic peptide level, and left ventricular ejection fraction. After propensity score matched analysis (Table), atrial tachyarrhythmia free survival was significantly higher in CBA group than in RFCA group (Figure).

Conclusions
Second generation CBA showed a significantly lower late recurrence rate compared to CF-guided RFCA.
Kaplan-Meier Curve

Funding Acknowledgement
Type of funding source: None
Risk factors and effective ablation strategy in patients presenting with left atrial flutter with no previous ablation for atrial fibrillation
Authors: Mohanty S , Trivedi C , Della Rocca D.G , Gianni C , Salwan A , Macdonald B , Mayedo A , Bassiouny M , Gallinghouse G.J , Burkhardt J.D , Horton R , Al-Ahmad A , Natale A 
Published: November 2020

Abstract

Background
A typical left atrial flutter (LAFL) may occur as a proarrhythmic complication of ablation for atrial fibrillation (AF).

Objective
We evaluated the risk factors and the best ablation strategy for LAFL in patients with no prior AF ablation.

Methods
Consecutive patients undergoing first catheter ablation for AFL with no prior procedure for AF were included in this prospective analysis. Based on the ablation strategy, patients were divided into, Group 1: PVI+ Flutter ablation (ablation of re-entry circuits) and Group 2: PVI+ Non-PV trigger ablation (targeting areas of focal activity as triggers). 3-D mapping of the LA was performed during tachycardia to identify the reentrant circuit.
PV isolation was performed in all patients. In group 1, ablation line was chosen to transect the area critical for the circuit (roof and mitral line). In group 2, ectopic beats arising from extra-PV foci detected by isoproterenol challenge were ablated. Off-drug success rate was assessed in all.

Results
A total of 92 and 90 patients were included in group 1 and 2 respectively. Baseline characteristics are provided in table 1. Pre-existent LA scar was detected in 91.3% and 90% of patients in group 1 and 2 respectively.
At 2 years of follow-up, 11/92 (12%) from group 1 and 60/90 (66.7%) from group 2 remained arrhythmia-free off-drugs (p&lt;0.001). In the multivariate analysis, PVI +flutter ablation was detected to be associated with significantly high risk of recurrence [HR: 3.92 (95% CI: 2.52–6.1, p&lt;0.001)]

Conclusion
In this series of patients presenting with LAFL with no earlier AF ablations, pre-existent left atrial scar was detected in majority of cases and PVI+ non-PV trigger ablation provided significantly better success rate than PVI+ flutter ablation.

Funding Acknowledgement
Type of funding source: None