bluuebunny/crossref_metadata_2025_split huggingface dataset:
P353Anticoagulation profile if an as required oral anticoagulation strategy is used in patients with complex cardiac devices
Authors: Briosa E Gala A , Pope M T , Leo M , Betts T R 
Published: June 2020

Abstract

Introduction
Once atrial fibrillation (AF) is detected and the threshold for oral anticoagulation (OAC) is met, patients are committed to lifelong anticoagulation. Stroke risk stratification tools, such as CHA2DS2-VAS score, do not incorporate AF burden. However, studies suggest a lower stroke risk in paroxysmal AF (pAF) and low AF burden when compared to persistent AF (persAF). Moreover, small feasibility studies have explored "as required" OAC guided by episode duration and/or AF burden in carefully selected, low-risk patients with infrequent episodes of AF. The reduction of OAC observed with stringent inclusion criteria may not be translated to real-world patients.

Purpose
We sought to investigate the impact of OAC reduction if an "as required" strategy is applied to an unselected population of patients with complex cardiac devices (implantable cardiac defibrillators [ICD] and cardiac resynchronisation therapy [CRT-D]).

Methods
All transmissions and electrograms of patients with CRT and ICD on remote monitoring were examined retrospectively. The first recorded AF episode longer than 6 minutes determined the start of follow-up. A weekly AF burden of 100% was considered persAF. We estimated the time on oral anticoagulation on an "as required" basis according to criteria used in previous studies: 1) OAC was initiated if the weekly burden was more than 0.6% (60 minutes); 2) OAC was discontinued if the weekly burden remained below 0.6 % in the following 4 weeks. Medical records were reviewed for baseline characteristics at the time of the first episode of AF.

Results
106(32%) had evidence of AF from 331 patients screened. Of these, 89% were male, age 64 ± 12 years, BMI 30 ± 6 kg/m2, LA diameter 4.5 ± 0.8 cm, ejection fraction (EF) 38 ± 17 and 58% had an ICD. 46 (43%) had persAF and 60 (57%) had pAF. The CHA2DS2VASc was 1 or higher in 104 patients (98%) corresponding to 393 patient-years of OAC if standard care was used. "As required" strategy led to a significant reduction in time on OAC to 248 patient years (62.3%, p &lt; 0.0001). The reduction was greater in pAF group (86.5%, p &lt; 0.0001) than in persAF (46.3%, p &lt; 0.0001)(Figure). Moreover, persAF patients had a higher number of episodes requiring OAC (3.6 ± 3.26 vs 2.2 ± 1.9) and of longer duration (mean difference 0.85 years, CI 0.5-1.1, p &lt; 0.0001).

Conclusion
In an unselected cohort of patients with complex cardiac devices "as required" OAC strategy led to a significant reduction in the total time of OAC, which was more marked in patients with pAF.
Abstract Figure
P988Classification of sinus rhythm potential morphology in patients with mitral valve disease
Authors: Van Schie M S , Starreveld R , Roos-Serote M C , Taverne Y J H J , Van Schaagen F R N , Bogers A J J C , De Groot N M S 
Published: June 2020

Abstract

Funding Acknowledgements
CVON-AFFIP [grant number 914728], NWO-Vidi [grant number 91717339], Biosense Webster USA [ICD 783454] and Medical Delta

Background
The morphology of atrial electrograms (EGMs) contains information on intra-atrial conduction and hence conduction disorders giving rise to development of atrial fibrillation (AF). Prior studies have indeed demonstrated that areas of abnormal EGM morphologies are indicators of electropathology underlying AF. By creating an electrical signal profile obtained from high-resolution mapping data of the entire atria during AF -a so-called AF Fingerprint- the severity and extensiveness of electropathology can be determined. The first step towards development of an AF Fingerprint, is understanding characteristics of EGM morphology during sinus rhythm (SR).

Objective
The goal of this study is to examine EGM morphology at a high resolution scale during SR in patients with mitral valve disease (MVD).

Methods
Intra-operative epicardial mapping (interelectrode distance 2mm) of the right and left atrium (RA, LA), Bachmann’s Bundle (BB) and pulmonary vein area (PVA) was performed during SR in 67 patients (27 male, 67 ± 11 years) with or without a history of paroxysmal atrial fibrillation (PAF). Unipolar single potentials (SPs) were classified according to their differences in relative R- and S-wave amplitude ratios.

Results
Epicardial EGMs revealed a wide variation of R/S ratios. A clear predominance of S-waves was observed at BB and the RA in both the no history of AF (no AF) and PAF group (BB 88.8% vs. 85.9%, RA: 92.1% vs. 85.1%, respectively). Differences between both groups were found at the RA, BB and LA (P = 0.021, P = 0.003 and P = 0.013, respectively). EGM voltages of the RA, BB and PVA in the no AF group were significantly higher compared to the PAF group (P &lt; 0.001, P &lt; 0.001 and P &lt; 0.001, respectively), and are mainly determined by the size of the S-waves amplitudes.

Conclusions
Though excitation of the atria during SR is heterogeneously disrupted in patients with MVD, a history of AF in this patient group is characterized by decreased SP amplitudes at BB due to loss of S-wave amplitudes. This, together with our findings that variation in EGM morphologies in our population is considerable, emphasizes the need for a diagnostic tool enabling identification of electropathology in the individual patient.
Abstract Figure. Potential morphology distribution
P512New approaches to pacing in children with atrioventricular block
Authors: Polyakova E , Kulbachinskaya E , Grishin I , Termosesov S , Shkolnikova M 
Published: June 2020

Abstract

Introduction
The placement of permanent pacemaker is presented as one of the most appropriate procedures in patients with congenital complete atrioventricular block (AVB). Despite video-assisted thoracic surgery (VATS) for epicardial lead placement has demonstrated positive results concerning the feasibility and freedom of complications in adults, its role in pacemaker implantation in children remains unclear.
The study aimed to assess the intermediate-term outcomes of video-assisted thoracic pacing in children with congenital complete AVB.

Methods
From May 2017 to November 2018, six children with complete idiopathic AVB underwent minimally invasive left ventricular lead placements via thoracoscopic video assistance. The procedure was performed under complex intratracheal anesthesia with single-lung ventilation, median operation time was 180 minutes (120–240). Four incisions were made, three of them were used to place the lead on the left ventricular, and one was needed to place the device. All pacing parameters were evaluated in perioperative and follow-up periods.

Results
Median age at implantation was 3 years (2 to 15 years), median weight 13 kg (12–46 kg). All procedures were completed successfully, pacing thresholds for the active lead measured 0.5-1.1V, with R-wave amplitude of 8-18 mV and impedance of 404-1478 Ohm. Increasing pacing thresholds in the third month after pacemaker implantation occurred in one patient, so anti-inflammatory therapy was assigned. Satisfactory thresholds and impedances with no significant difference with initial values were obtained at the median follow-up of 21 months (range: 10–28 months).

Conclusion
Video-assisted thoracic pacing may provide a potential alternative to the transthoracic approach of epicardial lead placement in children with congenital AVB.
P1446Cavo-tricuspid atrial flutter catheter ablation with a real zero fluoroscopic approach
Authors: Santoro A , Claudia Baiocchi C B , Nicolo Sisti N S , Francesca Falciani F F , Serafina Valente S V , Sergio Mondillo S M , Filippo Lamberti F L 
Published: June 2020

Abstract

Funding Acknowledgements
none

Background
Catheter ablation(CA)is the first-line therapy of cavo-tricuspid isthmus(CTI)atrial flutter. Sometimes an inversion of ablation catheter is necessary to obtain a complete bidirectional line block.
Purpose.The aim of this study was to describe this CA approach using electro-anatomical mapping(EAM)system with a zero-fluoroscopy(ZF)approach.Methods.Ninety-four patients that performed CA of CTI were retrospectively enrolled since 2017 to 2019.The studied population were divided in two groups.Group1(44patients) was composed of patients who underwent CA using ablation catheter without shaft visualization catheter(NSVC)on EAM.Group2(50patients)was composed of patients who underwent CA using ablation catheter with a shaft visualization(SVC). The catheter was looped at the Eustachian ridge after 200 seconds of RF without elimination of local electrogram.
Results.ZF CTI ablation was obtained in all patients of group 2 without fluoroscopy use.In six patients of group 1, the catheter inversion was used to obtain a complete CTI block.In NSVC group, the catheter inversion was obtained using fluoroscopy to avoid damages during loop of catheter ablation.In overall population studied SVC had a linear correlation with ZF approach(β=0.629;p &lt; 0.001). No differences were documented regarding acute and late success,complications.The procedural time between two groups was similar (Group1:83.4 ± 22.4 vs.Group2:80.2 ± 34.7minutes). The detailed results were summarize in table1.
Conclusions.A real ZF catheter ablation of atrial flutter is safe and feasible.The use of SVC could improve the reproducibility of a successful zero-fluoroscopy CA.The visualization of the shaft’s catheter permit to invert the catheter safely to overcome anatomic complexity of some CTI without fluoroscopy use.
detailed results Detailed results Group 1(44 CA) Group 2(50 CA) p value Procedure time (min) 83.4 ± 22.4 80.2 ± 34.7 NS AFL at begin CA (n.) 36 23 FT (min) 9.1 ± 9.8 0 ± 0 &lt; 0.001 PWRF (W) 32 ±2.5 33.6 ±2.2 NS CA line length (mm) 28.1 ± 4.1 27.9 ± 5.5 NS Total RF (min) 27.8 ± 6.3 13.6 ± 7.2 &lt; 0.01 SR during RF 35 23 Conductional block after 30 min 44 50 NS 6 months recurrences 1 1 NS AFL: atrial flutter; FT: fluoroscopy time; PWRF: power radiofrequencies; CA line length: length of line of radiofrequencies; RF: radiofrequencies; SR: sinus rhythm. Detailed results.
Abstract Figure.
P943The effects of ovariectomy on guinea pig cardiomyocyte intracellular calcium regulation and phosphorylation
Authors: Ching E , Firth J M , Francis A J , Islam N , Macleod K T 
Published: June 2020

Abstract

Background
Differences in cardiovascular disease risk between men and women have been partly attributed to the cardioprotective effects of oestrogen. Long-term oestrogen deficiency has been shown to alter cardiomyocyte intracellular calcium handling, but little is known about the mechanisms by which these changes occur. Oestrogen is thought to induce both genomic and non-genomic effects on cardiomyocytes, the latter including phosphorylation of calcium handling proteins.

Purpose
This study addresses the hypothesis that long-term oestrogen deficiency increases protein kinase A (PKA) and calcium/calmodulin-dependent kinase II (CaMKII) phosphorylation in cardiomyocytes, resulting in altered intracellular calcium regulation.

Methods
Female guinea pigs underwent sham (n = 7) or ovariectomy (OVx) (n = 8) operations and 150 days later, left ventricular myocytes were enzymatically isolated and loaded with fluo-4AM to monitor intracellular calcium. Calcium transients (CaT) were recorded using confocal microscopy. PKA and CaMKII phosphorylation were inhibited by superfusing cells with specific inhibitors, PKI and AIP, respectively. Experiments were carried out both in the presence and absence of β-agonist, isoprenaline (ISO), and relative changes to CaT parameters compared between OVx and sham cells.

Results
CaT amplitude was greater (p &lt; 0.05) in the OVx group (ΔF/Fo= 2.51 ± 0.57) compared with sham (ΔF/Fo = 2.16 ± 0.57). Inhibition of CaMKII phosphorylation increased CaT amplitude in the sham but not OVx group, both in the presence (by 22%, p &lt; 0.01) and absence of ISO (by 19%, p &lt; 0.01). Time to peak of the CaT increased to a greater extent following inhibition of PKA and CaMKII phosphorylation in the OVx group compared with sham, both in the presence (by 69%, p &lt; 0.0001) and absence (by 162%, p &lt; 0.0001) of ISO respectively. CaT decay time significantly increased (by 21%, p &lt; 0.01) in the sham group following inhibition of PKA and CaMKII together, whilst decay times in the OVx group remained unchanged in the presence and absence of ISO. At higher pacing rates, time to peak of the CaT decreased significantly (by 48%, p &lt; 0.01) in the OVx group but not sham with inhibition of phosphorylation.

Conclusion
Our findings suggest ovariectomy alters intracellular calcium regulation and some of these effects appear to be mediated by alterations in phosphorylation of calcium handling proteins and/or changes to sites of phosphorylation.
P469Minimally interrupted versus uninterrupted non-vitamin K anticoagulants for atrial fibrillation ablation. a meta-analysis of randomized controlled trials
Authors: Enache B , Del Castillo-Carnevali H , Lairez O , Postula M 
Published: June 2020

Abstract

Introduction
More and more patients undergoing atrial fibrillation (AF) ablation are anticoagulated with direct oral anticoagulants (DOAC). In order to balance the peri-procedural risk of bleeding with the risk of stroke, an important clinical question is whether to continue an interrupted DOAC administration or minimal interrupt by skipping the last one or two doses before the procedure. Dealing with rare events, the randomized controlled trials (RCTs) looking at this question have not been sufficiently powered to give a definitive answer.

Purpose
To do a systematic review of the literature comparing an uninterrupted DOAC strategy to minimally interrupted (1-2 doses) strategy in the setting of AF ablation in terms of peri-procedural stroke and bleeding.

Methods
PubMed, EMBASE, and Cochrane databases were searched for RCTs comparing a strategy of uninterrupted versus minimally interrupted DOAC administration for atrial fibrillation ablation. The primary endpoint was a composite of clinically significant adverse events: ischemic stroke, transient ischemic attack (TIA), systemic embolism, and major or minor bleeding events. A random-effects meta-analysis was performed on the resulting trials. The systematic review protocol was pre-registered in the PROSPERO database. The study selection process followed the PRISMA statement.

Results
After checking and removing duplicates, 188 articles were screened by reading the title and abstract. 8 of them were selected for a full text screening. Because 3 were not randomized, finally, 5 RCTs met the inclusion criteria. A total of 1 769 patients were included in the meta-analysis, and the sample size of the individual RCTs ranged from 97 to 846 patients. The overall prevalence of paroxysmal AF varied from 54% to 100%. The mean age of patients ranged from 63,5 to 70 years, and 21,6% to 32,8% of the trial populations were women. Comorbidities, such as hypertension, dyslipidemia, and diabetes, were common. Most patients had CHA2DS2-VASc &lt; 3; range from 1,7 to 2,7We found consistently low rates of strokes, TIAs, systemic embolisms and bleedings across all trials and both arms (RR = 0.98, 95% CI 0.69 – 1.38, I-squared = 0%, p = 0.874).

Conclusion
We found no evidence in favor of a difference between uninterrupted and interrupted administration of NOACs regarding the primary outcome of clinical thromboembolic and bleeding.
Abstract Figure. Meta-analysis of the primary outcome
P1401Electrophysiological findings during repeat procedures in patients exhibiting electrical isolation in all veins after an index cryoballoon procedure for paroxysmal atrial fibrillation
Authors: Varnavas V , Terasawa M , Sieira J , Abugattas J P , Stroker E , Maj R , Osorio T G , De Greef Y , Brugada P , De Asmundis C , Chierchia G B 
Published: June 2020

Abstract

Introduction
The purpose of this study was to analyze and compare the electrophysiological findings in redo radiofrequency (RF)-ablation of AF in a series of patients with durable PV isolation (PVI) and with PV reconnection after index procedure with the second-generation cryoballon (CB).

Methods and results
A total of 132 patients (81 males, 60.7 ± 12.4 years) who underwent CB-A for paroxysmal AF (PAF) were enrolled. Indication for the redo procedure was symptomatic (PAF) in 83 (63%) and persistent AF (PeAF) or persistent regular atrial tachycardia (RAT) in 49 (37%). Seventy-five (57%) patients presented a PV reconnection (PV group), whereas 57 (43%) no PV reconnection (non-PV group). The non-PV group exhibited significantly more atrial flutters and non-PV foci than the PV group after induction protocol (67% vs. 36%, p = 0.003 and 51% vs. 24% p = 0.002, respectively) (Table 1). Twenty-two (29.3%) patients of the PV group and 20 (35%) patients of the non-PV group had AF/RAT recurrence after a mean follow-up of 12.5 ± 8 months. The survival analysis demonstrated no statistical significance in recurrence between the two groups (log rank p = 0.358). In the cox regression analysis only the AF/RAT recurrence in the blanking period could predict independently an AF/RAT relapse.

Conclusions
AF/RAT recurrence in patients after CB-A with durable PVI is significantly associated to atrial flutters and non-PV foci. No statistically different success rate regarding AF/RAT freedom was detected between PV and non-PV Group after redo RF-CA.
Table 1. Electrophysiological findings PV Groupn = 75 non-PV Groupn = 57 p-value PV trigger (n of patients) 75(100) 0(0) &lt;0.001 LSPV 29 (39) 0 (0) &lt;0.001 LIPV 15 (20) 0 (0) &lt;0.001 RSPV 27 (36) 0 (0) &lt;0.001 RIPV 33 (44) 0 (0) &lt;0.001 Atrial flutters (n of patients) 27 (36) 38 (67) 0.003 Roof-flutter 13 (17) 34 (60) 0.0001 Peri-mitral-flutter 9 (12) 20 (35) 0.003 Right flutter 13 (17) 5 (9) 0.2 Non-PV foci (n of patients) 18 (24) 29 (51) 0.002 Categorical variables are expressed as absolute and percentage (in brackets). LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; PV, pulmonary vein; RSPV, right superior pulmonary vein; RIPV, right inferior pulmonary vein.
1264Genetic investigation of gap junction protein, alpha 5 of in Russian families with sick sinus syndrome
Authors: Chernova A , Nikulina S , Maksimov V 
Published: June 2020

Abstract

Background
Connexin 40 (Cx40) is a gap-junction protein expressed in the heart where it mediates the coordinated electrical activation of the atria and ventricular conduction tissues, facilitates cell-to-cell adhesion, and provides pathways for direct intercellular communication. Recent studies have shown that Cx40 null mice have cardiac conduction abnormalities with a very high incidence of cardiac malformations in heterozygous (18%) and homozygous (33%) animals, indicating that Cx40 plays a vital role in cardiomorphogenesis.The process that mediates interactions between an AV node cell and its surroundings that contributes to the process of the AV node cell communicating with a bundle of His cell in cardiac conduction. Encompasses interactions such as signaling or attachment between one cell and another cell, between a cell and an extracellular matrix, or between a cell and any other aspect of its environment.

Methods
This first study of SSS in a Russian population comprises the clinical and genetic investigation of 30 Russian families, including 67 members. The involvement of the Cx40 genes was investigated. The control group consisted of 615 patients without clinical ECG manifestations of cardiac diseases. All the examinees have undergone ECG, echocardioscopy, electrophysiological examination of the heart.

Results
We conclude that polymorphism 44AG has mutation-specific effects on Cx40-related SSS.

Conclusions
Mutation Cx40 impairs gap junction formation at cell-cell interfaces. This is the first demonstration of a germ line mutation in a connexin gene that emphasizes the importance of Cx40 in normal propagation in the specialized conduction system.
This study provides further evidence of the genetic heterogeneity of SSS.
P381Conduction heterogeneity: impact of atrial fibrillation and underlying heart disease
Authors: Heida A , Van Der Does W F B , Taverne Y J H J , Roos M C , Bogers A J J C , De Groot N M S 
Published: June 2020

Abstract

Funding Acknowledgements
CVON-AFFIP (914728), NWO-Vidi (91717339), Biosense Webster USA (ICD 783454) and Medical Delta.

Background
At present, it is unknown if intra-atrial conduction during sinus rhythm (SR) is influenced by prior atrial fibrillation (AF) episodes or by various underlying heart diseases (UHD). However, it is considered that structural and electrical remodeled atria contain more conduction abnormalities and prolonged conduction times (CTs).

Purpose
To determine the impact of AF episodes on conduction abnormalities and to distinguish conduction abnormalities between patients with ischemic heart disease (IHD), (ischemic and) valvular heart disease ((i)VHD) and congenital heart disease (CHD) by performing intraoperative high-resolution epicardial mapping.

Methods
The study population consists of 447 participants (325 male, age: 67.2 (58.9 – 73.1) years) with or without an history of AF (resp. N = 375 vs. N = 75) undergoing elective open heart surgery for either IHD (N = 238), (i)VHD (N = 169) or CHD (N = 40). High-resolution epicardial mapping of the right atrium (RA), Bachmann’s Bundle (BB), left atrium (LA) and pulmonary vein area (PVA) was performed during SR using a unipolar 128/192-electrode array (interelectrode distance: 2mm). Inter-electrode CTs (Δ local activation time between two adjacent electrodes) were quantified as the relative frequency distribution of CTs, cumulative incidence of CTs per patient (%) and the severity of CTs (%).

Results
Prior AF episodes were associated with prolongation of CTs (p &lt; 0.05). Patients with AF had a higher cumulative incidence of CTs ≥4ms throughout both atria, with a predilection site at BB and LA (p &lt; 0.05).
In the RA, conduction delays ≥48 ms were more present in patients with AF (44.0% versus 30.7%, p = 0.03), whereas in BB patients with AF already had more prolonged conduction delays ³16 ms (91.8% versus 81.2%, p = 0.03).
The relative frequency distribution of CTs did not differ between IHD, (i)VHD and CHD. Differences in the cumulative incidence of CTs between the three UHD were solely found at BB; patients with (i)VHD more frequently had incidence of CTs ³6ms than patients with IHD (p &lt; 0.017).
However, conduction delays were more pronounced in patients with CHD (≈≥30 – ≥84 ms) and with (i)VHD (≥72 – ≥84 ms)(p &lt; 0.017). Also, more patients with (i)VHD had prolonged conduction delays (≥24 – ≥34 ms) than patients with IHD (p &lt; 0.017).

Conclusions
Patients with AF had more and severer conduction abnormalities than patients without AF. Comparing the three UHD, mainly BB was affected by conduction abnormalities. (i)VHD was associated with more conduction abnormalities than IHD. Most severe conduction abnormalities were found in patients with CHD compared to both patients with IHD and (i)VHD. These findings indicate that the arrhythmogenic substrate is affected most by prior AF episodes, (i)VHD and CHD, and particularly present at BB.