bluuebunny/crossref_metadata_2025 huggingface dataset:
130Long-term outcomes of ventricular tachycardia substrate ablation incorporating hidden slow conduction analysis
Authors: Acosta Martinez J , Soto-Iglesias D , Jauregui-Garrido B , Fernandez-Armenta J , Penela D , Frutos-Lopez M , Arana-Rueda E , Pedrote A , Berruezo A
Published: June 2020

Introduction

Ventricular tachycardia substrate ablation (VTSA) incorporating hidden slow conduction (HSC) analysis allows further arrhythmic substrate identification. This study evaluates whether the analysis and elimination of HSC electrograms (HSC-EGMs) during VTSA procedures result in better short and long-term outcomes. 

Methods

Consecutive patients (n = 70, 63% ischaemic, 64 ± 14.6 years) undergoing VTSA were prospectively included. Bipolar EGMs with >3 deflections and duration <133 ms were considered as potential HSC-EGM, if located within/surrounding the scar area. Whenever a potential HSC-EGM was identified, a double ventricular extrastimulus was delivered. If a local potential showed up as a delayed component, it was annotated as HSC-EGM. The incidence of HSC-EGM in core, border-zone, and normal-voltage regions was determined. Ablation was delivered at conducting channel entrances and HSC-EGMs. Procedure time, radiofrequency time, VT inducibility after VTSA and VT recurrence at 12 months after the procedure were compared with data from a historic control group (n = 66, 70% ischaemic, 65.2 ± 12 years).

Results

5076 EGMs were analyzed. 1029 (20.2%) qualified as potential HSC-EGM, and 453 of them were tagged as HSC-EGMs. Scars in patients with HSC-EGMs (n = 43, 61.4%) were smaller (39.66 ± 28.2 vs 69.4 ± 38.2 cm2; p = 0.005) and more heterogeneous (core/scar area ratio 0.24 ± 0.2 vs 0.43 ± 0.17; p = 0.03). 29.6% of HSC-EGMs were located in normal-voltage tissue; 83.5% were targeted for ablation. Patients undergoing VTSA incorporating HSC analysis needed less procedure time (213 ± 75 vs 242 ± 60 min; p = 0.018), less RF time (15.9 ± 10 vs 25 ± 12,7 minutes; p < 0.001), had a lower rate of VT inducibility (27.5% vs 51.5%; p = 0.005) and a higher 2-year VT/VF-free survival (82.8% vs 59.7%; log rank p = 0.047) after VTSA than the historic controls .

Conclusion

VTSA incorporating HSC analysis allowed further arrhythmic substrate identification (especially in normal-voltage areas) and resulted in increased  VTSA efficiency and better short and long-term outcomes.

Abstract Figure. VT Recurrence-Free Survival
P551Permanent cardiac implantable device damage during direct photon exposure for oncologic radiotherapy: a multicentre, in-vitro observation
Authors: Di Girolamo E , Faustino M , Furia N , Appignani M , Marini M , De Filippo P , Leidi C , Delana A , Barbareschi A , Andreoli S , Genovesi D , Falco M D
Published: June 2020

Funding Acknowledgements

None

Backgroung. Direct photon exposure of cardiac implantable devices (CIEDs), both pacemakers (PMs) or implantable cardioverter defibrillators (ICDs), during oncologic radiotherapy (RT) courses may transiently or permanently affect normal device function.

Purpose

To evaluate CIED damage by direct exposure to doses up to 10 Gy in oncologic RT, commonly considered unsafe or even potentially harmful, 206 CIEDs (143 PMs and 63 ICDs) from three different centres, with at least 4 months to Elective Replacement Indicator (E.R.I.) were observed.

Methods. All CIEDs had a baseline telemetry interrogation. Single chamber devices were programmed in the VVI/40 mode and dual or triple chamber ones were programmed in the DDD/40 mode. Rate adaptive function was disabled. In ICDs, antitachycardia therapies were disabled with the ventricular tachycardia/fibrillation window left enabled. A centering Computed Tomography was performed to build the corresponding treatment plan and CIEDs were blinded randomized to receive either 2, 5 or 10 Gy (direct exposure) by a 6 MV linear accelerator in a home-made water phantom. An in-vivo dosimetry randomly assessed the effective dose received by the CIEDs. All CIEDs were interrogated immediately after exposure and monthly during a three-month follow-up.

Results. Immediately after photon exposure, no changes in device setting or software errors were observed in 205 CIEDs (99·5%). Reset to emergency back-up mode was observed in a PM (0·49% overall; 0·7% among PMs). Seven PMs reached the E.R.I immediately after exposure (3·4% overall; 4·9% among PMs). Sixteen ICDs (7·8% overall; 25·4% among ICDs) reported multiple ventricular  tachycardia/fibrillation detections stored in the device memory. During follow-up, a non-reprogrammable software reset (emergency backup VVI/65 mode) was observed in one PM after a single dose of 2 Gy (0·49% overall; 0.7% among PMs), whereas an abnormal battery drain was observed in 6 PMs (2.9% overall; 4.2% among PMs). No battery issues were observed in ICDs. All reported events occurred regardless of either 2, 5, or 10 Gy direct exposure. Malfunctions were observed in only older CIEDs.

Conclusions. Recent CIEDs have shown to be safe during oncologic RT, withstanding direct exposure up to 10 Gy, commonly considered not recommended or even unsafe by manufacturers statements and clinical guidelines. Malfunctions occurred solely in older devices.
848Ultrasound-guided axillary vein puncture feasibility for complex cardiac devices implantation
Authors: Bun S-S , Squara F , Scarlatti D , Theodore G , Latcu D G , Hasni K , Benaich F A , Enache B , Saooudi N , Allouche E , Diakite M , Ferrari E
Published: June 2020

Background

The axillary route use for cardiac devices implantation has recently expanded either with fluoroscopy or ultrasounds guidance. Few studies included defibrillators (ICD), cardiac resynchronization therapy (CRT) and upgrade procedures for ultrasound-guided axillary vein puncture (UGVP).

Puropose

To assess the feasibility/safety of UGVP for complex cardiac devices implantation including CRT/ICD.

Methods

Consecutive patients eligible for a pacemaker or ICD implantation were included.

All procedures were performed by three operators (one experienced and two fellows). Guidewires insertion time (from lidocaïne administration), and complications were systematically studied. A group of patients implanted with alternative techniques was used for comparison (cephalic, subclavian).

Results

In 176 consecutive patients in whom UGVP was used, a total of 68 complex procedures were analyzed (74 ± 8 y, male 61 %) with 138 leads implanted including 42 ICD, 48 CRT and 16 upgrade procedures. A majority (83 %) was under anti-thrombotic therapy. UGVP was successful in 96.8 %. Mean insertion time for 1.78 guidewires per patient was 4.4 ± 4.4 min.  Guidewires insertion time reached its plateau after 10 patients. One pocket hematoma (1.4 %) was drained during a mean follow-up of 12 ± 5 months. The control group included 28 patients (12 subclavian, 16 cephalic; 15 ICD, 18 CRT, 4 upgrade procedures), with a mean insertion time of 10 ± 8 min, for 1.95 guidewires per patient (p < 0.0005).

Conclusion

UGVP is feasible and safe even for complex device implantations including CRT/ICD and upgrade procedures.
P557Does the reduced left ventricle ejection fraction affect the results of transvenous lead extraction?
Authors: Polewczyk A , Jachec W , Segreti L , Bongiorni M G , Kutarski A
Published: June 2020

Background

Reduced left ventricle ejection fraction (LVEF) is a common risk factor of complications in patients undergoing different procedures.

Aim of study

The aim of the study was to assess  efficiency and safety of transvenous lead extraction (TLE) procedures in patients with reduced LVEF (< 40%) compared to patients with mid-range reduced and preserved LVEF (≥40%).

Study group

Data from 3434 of TLE procedures (patient"s age during TLE-65,5 ± 15,5 years, female; 1168 (34,01%), performed in two high volume European Centers (PISA – Italy, Lublin-Zamość – Poland) were analysed.

Results

In group with reduced LVEF (A) compared to the group of patients with LVEF ≥ 40% (B) the smaller number of female was found (p < 0,001). The number of devices with ICD leads was higher in group A (p < 0,001). Dwelling time for oldest lead and the oldest extracted lead were longer in group B (p < 0.001).  There were no differences in indications for TLE between presented groups. The procedure duration time was similar in both groups. There were no statistically significant differences in complete procedural success, clinical success, major and minor complications and procedure related death occurrence. Complete results are presented in  Table.1

Conclusion

The effectiveness and safety of TLE in patients with reduced left ventricle ejection fraction does not differ from the results of the TLE procedures in patients with mid-range reduced and preserved LVEF.

Abstract Table
P1014The natural history of atrial fibrillation after the first clinical episode: a prospective observational study via implantable loop recorders
Authors: Papakonstantinou P , Simantirakis E , Kanoupakis E , Parthenakis F , Vardas P
Published: June 2020

Funding Acknowledgements

The study was supported by Medtronic Inc

Background

The natural history of paroxysmal atrial fibrillation (AF) after the first clinical AF episode is not well known. AF burden is of clinical significance as it may have clinical implications concerning the long-term management of the arrhythmia and the decision-making on AF patients. 

Purpose

To observe the natural history of AF in patients after their first clinical paroxysmal AF episode. 

Methods

Thirty consecutive patients (age 66.9 ± 10 years; 14 men) received an implantable loop recorder (ILR) after their first symptomatic paroxysmal AF episode. We recorded the AF recurrences and burden (clinical and subclinical AF) during a follow-up period of three years. We excluded patients with persistent or permanent AF and patients with an episode of AF attributed to reversible or transient causes. 

Results

Eight patients (26.6%) did not present any AF recurrence during the first year of the follow-up period. Five patients (16.6%) did not also suffer any AF episode during the second year, while in three patients (10%) no AF episode was recorded during the three-year follow-up period. In 16 patients (53.3%) the AF burden was increased during the second year of follow-up period while in 9 patients (30%) the AF burden was decreased. During the third year of follow-up period the AF burden was increased in 19 patients (63.3%), decreased in 7 patients (23.3%) and remained almost the same in 4 patients (13.3%). Five patients (16.6%) presented at least one episode of persistent AF during the follow-up period. Seven patients (23.3%) suffered only from symptomatic AF episodes, while in nine patients (30%) only asymptomatic AF episodes were recorded. Eleven patients (36.7%) had both types of AF episodes (symptomatic and asymptomatic). 

Conclusions

The AF recurrence and burden increased in most AF patients during the three-year follow-up period. However, some patients did not suffer any AF recurrence or they presented a decrease in AF burden. Paroxysmal AF clinical profile differs among the AF patients significantly and this indicates that an individualized approach via long-term rhythm monitoring may be of clinical significance, at least in some newly diagnosed AF patients.
P575Usefulness of late gadolinium enhancement cardiac magnetic resonance to predict appropriate therapies in implantable cardioverter defibrillator patients in primary prevention
Authors: Sanchez Somonte P , Zaraket F , Quinto L , Garre P , Alarcon F , Tolosana J M , Guasch E , Arbelo E , Doltra A , Ortiz J M , Borras R , Prat S , Martin Sanchez G , Mont L , Roca Luque I
Published: June 2020

Funding Acknowledgements

No funding acknowledgements

OnBehalf

VT and sudden cardiac death

Background

  The scar and the amount of border zone measured by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) has been proposed as an independent predictor of ventricular arrhythmias in patients with ischemic and non-ischemic cardiomyopathy. However, at the present time, the guidelines are based only on the ejection fraction to recommend an implantable cardioverter defibrillator (ICD) in primary prevention, and only a minority of these patients receive appropriate therapies. So, prevention needs to be improved.

Purpose

To identify predictors of appropriate therapies in patients with a primary prevention ICD using cardiac magnetic resonance imaging and a dedicated software (ADAS-3D) to characterize the scar.

Methods

All consecutive patients who underwent a LGE-MR prior to ICD implantation in primary prevention were prospectively included.  Clinical and cardiac imaging characteristics were collected. The myocardium was segmented with ADAS-3D software in 10 layers (from endocardium to epicardium). The scar, border zone, core and conducting channels were automatically measured in grams by the software.

Results

Since 2008 to 2017, 206 patients were included. Mean age was 67 +/- 28 years, 80% men, mean ejection fraction 26%+/-9, 52% with ischemic cardiomyopathy and 48% non-ischemic. The primary endpoint was appropriate therapies and/or sudden cardiac death (SCD). Median follow-up was 46,33 months.  46 patients (22%) reached the primary endpoint. Greater scar mass  (36,05 grams vs 21,5 grams; HR 1.04; 95% CI (1.03-1-05), p <0.001), core mass (9,8 grams vs 5,6 grams; HR 1.06; 95% CI (1.04-1-09), p <0.001),  border zone mass (26,2 grams vs 15,9 grams; HR 1.05; 95% CI (1.04-1-09), p <0.001) and channel mass (3,0  grams vs 1,6 grams; HR 1.15 95% CI (1.06-1.25), p <0.001) were associated with appropriate therapies and SCD.  A border zone mass >5.3 grams was independently associated with the primary endpoint (HR: 4.77; 95% CI (1.15-19.73), p = 0.03).

Conclusions

 The amount of border zone, core and channel mass measured by LGE-MR and ADAS software are independent predictors of appropriate therapies and SCD in patients with ICD in primary prevention.

Abstract Figure. Scar characterization
P1497Digoxin in patients with advanced heart failure and sinus rhythm - Is there any benefit?
Authors: Lopes J , Fernandes C , Madeira M , Antonio N , Elvas L , Goncalves L
Published: June 2020

Background

Digoxin is one of the oldest drugs used in heart failure treatment. It is recommended in patients in sinus rhythm with still symptomatic heart failure with reduced ejection fraction. However, a controversy regarding digoxin use has risen with recent studies demonstrating an increased mortality and arrhythmias rate in patients taking this drug.

Purpose

The purpose of this study is to assess the prognostic impact of digoxin in patients in sinus rhythm with a CRT device, concerning all-cause mortality, hospitalizations due to acute heart failure and rate of ventricular arrhythmias.

Methods

A cohort of 297 consecutive P with advanced HF, sinus rhythm and a CRT device (80% with defibrillator) implanted between February 2004 and January 2016, in a single centre, was included in this retrospective study.

Patients were divided in two groups regarding digoxin prescription (digoxin (DG) and without digoxin (NDG)).  A mean clinical follow-up of 5.3 ± 3.4 years regarding long term outcomes was performed. Cox regression was used to identify independent predictors of outcomes.

Results

Digoxin was prescribed in 104 P (35%). In this cohort 67% of P were males and the mean age was 64 ± 11 years. Patients in DG were younger (60 ± 11 vs 66 ± 10, p < 0.001).  The 2 groups had similar prevalence of comorbidities, with exception of chronic kidney disease (GD 27.5% vs GND 33.3%, p = 0.05). The etiology was similar between the 2 groups (42% ischaemic).

In the qui-square analysis, there was a statically significant association between the use of digoxin and mortality (DG 42.3% vs NDG 25.4%, p= 0.003), and also between digoxin and hospitalization with acute heart failure (DG 36.5% vs NDG 21.4%, p = 0.005). There was no association between digoxin use and the occurrence of ventricular tachycardia (DG 31.7% vs 40.1%, p = 0.155).

In the Cox proportional hazards regression, accounting for the potential confounders, the use of digoxin was an independent predictor for all-cause mortality (HR = 2.80, CI 95 [1.07 – 7.31], p = 0.036) and also for hospitalization with acute heart failure (HR = 5.82, CI 95 [1.54 – 22.06], p = 0.010).

Conclusion

The use of digoxin was an independent predictor of all-cause mortality and hospitalizations due to acute heart failure. Randomized trials are needed to clarify the impact of digoxin and determine if it is only an indicator of disease severity and worse prognosis or if the drug has a direct negative influence in the natural history of P with heart failure.

Abstract Figure.
P994Does AF always beget AF? Retrospective study in patients with complex cardiac devices
Authors: Briosa E Gala A , Pope M , Leo M , Betts T R
Published: June 2020

Introduction

Atrial fibrillation (AF) is conventionally divided in paroxysmal AF (PAF) and persistent AF (PersAF) according to episode duration, with a perceived inevitable progression of the arrhythmia in most patients: "AF begets AF". This dichotomous classification of AF is currently being challenged by continuous monitoring with implantable cardiac monitors and pacemakers which suggest different patterns of AF with considerable variation in AF burden. 

Purpose

This study sought to examine the long-term progression of AF burden in patients with complex cardiac devices (implantable cardiac defibrillators [ICD] and cardiac resynchronisation therapy-defibrillators [CRT-D]).

Methods

This retrospective study examined the weekly AF burden in patients with ICDs and CRT-Ds and on remote monitoring between January 2010 and July 2019.  All transmissions and electrograms were assessed for the presence of AF lasting more than 6 minutes.  The first episode of AF determined was considered follow-up year 0.  PersAF was defined as a weekly AF burden of 100%. Medical records were reviewed for baseline characteristics at the time of the first episode of AF and interventions that may affect burden such as direct current cardioversion (DCCV) and catheter ablations.

Results

Of 331 patients on remote monitoring, 106 (32%) had evidence of AF. Of these, 89% were male, age 64 ± 12 years, BMI 30 ± 6 kg/m2, LA diameter 4.5 ± 0.8 cm, 58% had an ICD, 10% had previous AF ablation and 27% had antiarrhythmic medication. Forty-six (43%) had PersAF and 60 (57%) had PAF over a total follow-up of 393 patient years (mean follow-up 4.6. ±2.1).  The mean AF burden  was 1.2 ± 4.4% in PAF and 66.4 ± 35.3% in PersAF at the end of the first year of follow-up. When compared to year 1, the mean annual AF burden did not increase in the PAF and PersAF groups. Moreover, the PersAF patients had a significant reduction in the mean annual AF burden up to year 7 of follow-up. In year 8, the mean annual AF burden remained below year 1; however, due to a low number of patients (5) it did not reach statistical significance (mean difference 15.1%, p = 0.06) . To further assess individual progression in PersAF patients, the annual AF burden was subdivided in 4 categories (<25%, 25%-50%, 50%-75% and >75%). In 30 (65%) patients it remained unchanged, in 5(11%) it worsened and in 11 (24%) it improved (Figure ). Moreover, 35 (76%) patients reverted to sinus rhythm following their first episode of PersAF (5 following DCCV and 2 after catheter ablation). 

Conclusions

In this cohort,  the mean AF burden did not increase; in fact, we observed a significant reduction in patients with PersAF despite a low rate of interventions. These findings reinforce the emerging concept of AF as a heterogenous disease with various phenotypes that challenge the current simplistic binary classification.

Abstract Figure
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

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 < 0.0001). The reduction was greater in pAF group (86.5%, p < 0.0001) than in persAF (46.3%, p < 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 < 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

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 < 0.001, P < 0.001 and P < 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

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

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 < 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 < 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 < 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

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 < 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 < 0.01) and absence of ISO (by 19%, p < 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 < 0.0001) and absence (by 162%, p < 0.0001) of ISO respectively. CaT decay time significantly increased (by 21%, p < 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 < 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

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 < 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

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) <0.001 LSPV 29 (39) 0 (0) <0.001 LIPV 15 (20) 0 (0) <0.001 RSPV 27 (36) 0 (0) <0.001 RIPV 33 (44) 0 (0) <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

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

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 < 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 < 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 < 0.017).

However, conduction delays were more pronounced in patients with CHD (≈≥30 – ≥84 ms) and with (i)VHD (≥72 – ≥84 ms)(p < 0.017). Also, more patients with (i)VHD had prolonged conduction delays (≥24 – ≥34 ms) than patients with IHD (p < 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.
P945What is the role of late-potentials determined by signal-averaged ECG in predicting flecainide provocative test in brugada pattern?
Authors: Brito J , Cortez-Dias N , Nunes-Ferreira N , Aguiar-Ricardo I , Silva G , Rigueira J , Silverio Antonio P , Rodrigues T , Cunha N , Santos R , Sobral S , Ribeiro J , Carpinteiro L , Pinto F J , Sousa J DE
Published: June 2020

Introduction

The sudden cardiac death risk in Brugada Syndrome (BrS) is higher in patients with spontaneous type 1 pattern. Brugada diagnosis is also established in patients with induced type 1 morphology after provocative test with intravenous administration with a sodium blocker channel. Nevertheless, this group of patients is known to be at a lower risk of SCD, and their risk stratification is still a matter of discussion.  Late potentials (LP) detected on signal-averaged ECG (SAECG) on the RVOT have been previously proposed as a predictor factor for BrS, even though data is lacking on its value.

Purpose

To evaluate the association between positive LP (LMS40> 38ms) on SAECG with modified Brugada leads and a positive flecainide test in patients with non-type 1 BrS.

Methods

Retrospective single-center study of non-type 1 BrS patients referred for the performance of a flecainide provocative test. Patients presenting with spontaneous type 1 morphology were excluded from the study. Study of LP on SAECG with modified leads for Brugada were evaluated before administration of flecainide [2mg/kg (maximum150mg), for 10minutes] with determination of filtered QRS duration (fQRS), root mean square voltage of the last 40ms of the QRS complex (RMS40) and duration of low amplitude signals <40μV of the terminal QRS complex (LMS40).

Results

126 patients (47.3 ± 14.1 years, 61.9% males) underwent study with LP SAECG and flecainide test. Among these patients, 7.9% were symptomatic and 16.7% had familiar history of BrS. Flecainide test was positive in 46.8% of patients.

In patients with a positive flecainide test, 64.4% presented LMS40 > 38ms whereas LMS40 > 38ms was present in only 46% of those with a negative flecainide test (p = 0.031). The presence of positive LMS40 was a positive predictor for a positive flecainide test, associated with a two-fold increase likelihood in the induction of a Brugada pattern (OR: 2,12; IC95% 1,025-4,392; P = 0,043).

There was no association between fQRS or RMS40 and a positive flecainide test (p = NS). fQRS > 114ms and RMS40 <20uV was present in 22% and 61% of patients with a positive flecainide test, respectively.

Conclusion

In patient with non-type 1 Brugada syndrome, LMS40 > 38ms in SAECG was a predictor for a positive flecainide test, suggesting that this finding could be helpful on the risk stratification of patients undergoing diagnostic study for Brugada syndrome.

Abstract Figure. Effect of LMS 40 in flecainide test
P1464A question of gender equality. Sex-related differences in survival after primary prevention implantable cardioverter-defibrillator implantation for dilated cardiomyopathy An analysis from POLKARD
Authors: Warchol I , Lubinski A , Sterlinski M , Kowalski O , Goscinska-Bis K , Pytkowski M , Mitkowski P , Kazmierczak J , Szwed H , Przybylski A , Trusz-Gluza M , Kempa M , Zienciuk-Krajka A , Sielski S , Pazdyga A
Published: June 2020

OnBehalf

POLKARD Polish ICD Registry

Background

The protective effects of implantable cardioverter defibrillators (ICDs) in the primary prevention of sudden cardiac death of patients presenting with left ventricular (LV) systolic dysfunction are unequivocal. Nevertheless, female underrepresentation has been a consistent finding in all randomized controlled primary prevention ICD trials. Surprisingly, there is a vast body of literature on female primary prevention ICD patients exhibit a lower overall mortality.

Purpose

Therefore, we analyzed data from a large, nationwide POLKARD registry to evaluate the effect of sex on survival after primary prevention cardioverter-defibrillator implantation for dilated cardiomyopathy.

Methods

All patients enrolled in the Polish ICD Registry from 2008 to 2014 were identified. Patients were included in the study if they were designated as receiving an ICD for primary prevention of SCD after documented non-ischeamic cardiomyopathy. Kaplan-Meier survival analysis was used to assess all-cause mortality.

Results

Of the 964 ICD recipients, 241 (25%) were women (mean age of 64± 0,45 years). During a mean follow-up of 5,53 ± 2,48 years 32% of women and 42% of men died. Kaplan-Meier curve depicted a significantly lower mortality for women than for men (p = 0,05). The median survival time was 6,73 years (55 deaths per 1000 person-years) versus 6,37 years (78 deaths per 1000 person-years) for women and men, respectively.

Conclusions

In agreement with previous studies, our data indicate that primary prevention implantation rates for dilated cardiomyopathy are lower in women. However, the reasons are not entirely understood.