bluuebunny/crossref_metadata_2025 huggingface dataset:
BeadNet: deep learning-based bead detection and counting in low-resolution microscopy images
Authors: Scherr Tim , Streule Karolin , Bartschat Andreas , Böhland Moritz , Stegmaier Johannes , Reischl Markus , Orian-Rousseau Véronique , Mikut Ralf
Published: June 2020

Motivation

An automated counting of beads is required for many high-throughput experiments such as studying mimicked bacterial invasion processes. However, state-of-the-art algorithms under- or overestimate the number of beads in low-resolution images. In addition, expert knowledge is needed to adjust parameters.

Results

In combination with our image labeling tool, BeadNet enables biologists to easily annotate and process their data reducing the expertise required in many existing image analysis pipelines. BeadNet outperforms state-of-the-art-algorithms in terms of missing, added and total amount of beads.

Availability and implementation

BeadNet (software, code and dataset) is available at https://bitbucket.org/t_scherr/beadnet. The image labeling tool is available at https://bitbucket.org/abartschat/imagelabelingtool.

Supplementary information

Supplementary data are available at Bioinformatics online.
Optimal Slack Stealing Servicing for Real-Time Energy Harvesting Systems
Authors: El Osta Rola , Chetto Maryline , El Ghor Hussein
Published: June 2020

We consider the problem of real-time scheduling in uniprocessor devices powered by energy harvesters. In particular, we focus on mixed sets of tasks with time and energy constraints: hard deadline periodic tasks and soft aperiodic tasks without deadlines. We present an optimal aperiodic servicing algorithm that minimizes the response times of aperiodic tasks without compromising the schedulability of hard deadline periodic tasks. The server, called Slack Stealing with energy Preserving (SSP), is designed based on a slack stealing mechanism that profits whenever possible from available spare processing time and energy. We analytically establish the optimality of SSP. Our simulation results validate our theoretical analysis.
The Social-Origins Gap in Labour Market Outcomes: Compensatory and Boosting Advantages Using a Micro-Class Approach
Authors: Bernardi Fabrizio , Gil-Hernández Carlos J
Published: June 2020

Recent studies document a social-origins gap or direct effect of social origin (DESO) on labour market outcomes over and above respondents’ education, challenging the idea that post-industrial societies are education-based meritocracies. Yet, the literature offers insufficient explanations on DESO heterogeneity across education and different labour market outcomes. Little is also known about underlying mechanisms. We contribute by answering two questions: (i) How does DESO vary when comparing college-degree holders with non-holders? (ii) For which specific parental and children’s occupations is the largest DESO observed? We focus on Spain, using a large new dataset (n = 144,286). Firstly, we find a larger DESO on socioeconomic status among non-degree holders, and on income among degree holders. We propose the notions of compensatory advantage in occupational attainment and boosting advantage in income for high social-origin individuals to explain these opposite patterns, drawing from ‘downward mobility avoidance’ and ‘effectively maintained inequality’ theories. Secondly, we map origin and destination micro-classes where DESO is largest. High-grade managerial and professional parental occupations, characterized by social closure and influence in large organizations, are the origin micro-classes exerting the largest DESO. We also find that compensatory advantage for low-educated children from advantaged origins is related to their higher chances of accessing managerial occupations, while boosting advantage on income among college graduates is observed for high-grade managers and liberal professionals, suggesting that micro-class reproduction may partially account for boosting advantage. We conclude by discussing the generalizability of our findings to other countries and their implications for research on DESO, meritocracy and social mobility.
P1127Occurrence, management and outcomes of iatrogenic aortic dissections as a complication of catheter ablation. A multicenter study
Authors: Futyma P R , Aksu T , Cooper J M , Schaller R , Winterfield J , Payne J , Omarov M , Vazquez O , Guler T E , Bozyel S , Zahwe F , Gautam S , Futyma M , Vijayaraman P , Kulakowski P
Published: June 2020

Background

Data on occurrence, management and outcomes of iatrogenic aortic dissections (IAD) as a complication of catheter ablation (CA) do not exist.

Purpose

To evaluate multicenter data on occurrence, management and outcomes of IAD as a complication of CA.

Methods

Data on occurrence, management and outcomes of documented vascular dissections from 10 centers were evaluated.

Results

IADs occurred in 7 patients (2 females, age 63 ± 8 years). Indications for CA were frequent premature ventricular complexes (PVC)/ventricular tachycardia (VT) in 6 patients (86%) and left-sided accessory pathway in the remaining one (14%). Hypertension was most frequent comorbidity (4 pts, 57%).  All IADs occurred during retrograde advancement of ablation catheter. In the vast majority of patients creation of IAD during catheter advancement was not associated with any symptoms (6 pts, 86%). IAD was initially detected using trans-luminal angiogram in 5 (71%) and further confirmed using computed tomography (CT) (5 pts, 71%), conventional angiography (2 pts, 28%) and ultrasound (2 pts, 28%). One IAD was detected during CT scan performed for other indication after CA. There was one IAD-related death and IAD was evaluated post-mortem. Follow-up lasted 10 ± 19 months. Four patients were treated conservatively, one patient underwent descending aorta stenting and one femoral artery stenting.

Conclusions

IAD during CA is a rare but can be devastating. Early recognition can be difficult. Conservative management of IAD is an option of treatment.
P370Added value changes in signal sonr in patients with = <30% left ventricular ejection fraction
Authors: Garcia Guerrero J J , Fernandez De La Concha Castaneda J , Chacon Pinero A , Garcia Fernandez J , Fernandez Lozano I , Perez Castellanos N , Moreno Planas J
Published: June 2020

Abstract/Introduction

Decompensated congestive heart failure (CHF) is a main and increasing health problem worldwide, which leads to patients’ bad outcomes and high money expenditure. Direct relationship between Brain Natriuretic Peptides (NT-proBNP) increasing levels and adverse clinical outcomes have been demonstrated in patients with CHF.  SonR signal sensor, a micro-accelerometer embedded in the tip of the atrial lead in patients implanted with devices, picks up cardiac muscle vibration. Its amplitude is a surrogate for cardiac contractility, which is found to be further reduced in patients with decompensated CHF.

Purpose

We sought to find a significant inverse correlation between SonR signal and NT-proBNP levels, in order to use SonR as a surrogate of NT-proBNP to anticipate worsening CHF leading to hospital admission.

Methods

AVCs SONR trial is a pilot, prospective, observational, multicentre study, in which patients with dilated cardiomyopathy, any aetiology, LV ejection fraction ≤ 30%, at least one recent (< 1 year) hospital admission due to CHF, and implanted with CRT-D devices (used as dual-chamber, no left ventricular (LV) lead implanted) with SonR sensor feature, were enrolled. During a year, NT-proBNP and SonR values were obtained every month, and both levels compared (Pearson’s test)

Results

This an interim analysis of our data, 18 months after the first patient was enrolled. Twenty two patients and 116 data pairs were analysed. Most patients were men (91%) and had ischemic dilated cardiomyopathy (59%). Mean age was 61 (range 34-82) and mean LV ejection fraction was 27% (range 15-30). The mean Pearson’s correlation coefficient of the NT-proBNP values and the SonR signal was r = - 0.36 (95% CI -0.51 to -0.19), p < 0.00006 (Figure)

Conclusions

The interim analysis of this study shows an inverse and very significant relationship between SonR signal and NT-proBNP values. This suggests SonR signal might be used as predictor of worsening CHF.

Abstract Figure
P1113Patchy localisation of late gadolinium enhancement associated with ventricular arrhythmia in dilated cardiomyopathy
Authors: Pooranachandran V , Mistry A , Vali Z , Li X , Sidhu B , Ng G A
Published: June 2020

Funding Acknowledgements

None

Introduction

Myocardial fibrosis detected using late gadolinium enhancement(LGE) on cardiac magnetic resonance(CMR) imaging holds prognostic value in dilated cardiomyopathy(DCM). Recent reports have demonstrated the localisation of LGE to be promising predictors of ventricular arrhythmic (VA).Aim: To determine the localisation of LGE associated with high risk of VA in DCM patients. Methods: Retrospective review of consecutive DCM patients(n = 85) implanted with an implantable cardioverter defibrillator(ICD) at a single tertiary centre between 2011-2018. All patients with insufficient follow-up data, cardiac channelopathies, primary valvular pathology and congenital heart disease were excluded from analysis(n = 11). Details of VA occurrence were obtained from medical and pacing notes. VA was defined as VA causing haemodynamic compromise or appropriate device therapy (anti-tachycardia pacing/shock). Localisation of LGE was defined as midwall, patchy, subepicardial or transmural. Left ventricular ejection fraction(LVEF) <35% was defined as severely impaired function. Results:74 DCM patients implanted with an ICD were identified for analysis; LGE was observed in 18(60%) VA and 29(66%) non-VA patients(p = 0.6). There was no observed difference in mean age for patients with and without LGE (68 ± 10 vs. 65 ± 10 years,p = 0.07). A significant difference was seen between localisation and VA (p = 0.04), with patchy LGE demonstrating a higher arrhythmic risk(p = 0.005). There was no association between LVEF and LGE(p = 0.2) however, a significant difference was seen in LVEF and arrhythmic risk, with a more severely impaired LV function seen in patients without VA(p = 0.01). Conclusion:This study has demonstrated a patchy LGE localisation to be strongly associated with ventricular arrhythmia in DCM. Whilst this is a valuable tool in risk stratification, a prospective study with a larger population is required to confirm the validity of this finding. Moreover, an additional method will need to be considered to identify high risk patients without LGE.

Ventricular Arrhythmia (n = 30) No Ventricular Arrhythmia (n = 44) P Value Male(%) 20(67%) 24(55%) p = 0.29 Age(Mean ± SD) 65 ± 12 65 ± 10 p = 0.36 LGE Midwall 10(56%) 24(83%) p = 0.04 Subepicardial 1(5.5%) 2(7%) p = 0.85 Transmural 1(5.5%) 2(7%) p = 0.85 Patchy 6(33%) 1(3%) p = 0.005 LVEF <35% 23(77%) 42(95%) p = 0.01
743Combining deep learning method with optical coherence tomography for ablation lesion assessment
Authors: Liang D , Haeberlin A
Published: June 2020

Background

The immediate effect of radiofrequency catheter ablation (RFA) on the tissue is not directly visualized. Optical coherence tomography (OCT) is an imaging technique that uses light to capture histology-like images with a penetration depth of 1-3 mm in the cardiac tissue. There are two specific features of ablation lesions in the OCT images: the disappearance of birefringence artifacts in the lateral and sudden decrease of signal at the bottom (Figure panel A and D). These features can not only be used to recognize the ablation lesions from the OCT images by eye, but also be used to train a machine learning model for automatic lesion segmentation. In recent years, deep learning methods, e.g. convolutional neural networks, have been used in medical image analysis and greatly increased the accuracy of image segmentation. We hypothesize that using a convolutional neural network, e.g. U-Net, can locate and segment the ablation lesions in the OCT images.

Purpose

To investigate whether a deep learning method such as a convolutional neural network optimized for biomedical image processing, could be used to segment ablation lesions in OCT images automatically.

Method

8 OCT datasets with ablation lesions were used for training the convolutional neural network (U-Net model). After training, the model was validated by two new OCT datasets. Dice coefficients were calculated to evaluate spatial overlap between the predictions and the ground truth segmentations, which were manually segmented by the researchers (its value ranges from 0 to 1, and "1" means perfect segmentation).

Results

The U-Net model could predict the central parts of lesions automatically and accurately (Dice coefficients are 0.933 and 0.934), compared with the ground truth segmentations (Figure panel B and E). These predictions could reveal the depths and diameters of the ablation lesions correctly (Figure panel C and F).

Conclusions

 Our results showed that deep learning could facilitate ablation lesion identification and segmentation in OCT images. Deep learning methods, integrated in an OCT system, might enable automatic and precise ablation lesion visualization, which may help to assess ablation lesions during radiofrequency ablation procedures with great precision.

Figure legend

Panel A and D: the central OCT images of the ablation lesions. The blue arrows indicate the lesion bottom, where the image intensity suddenly decreases. The white arrows indicate the birefringence artifacts (the black bands in the grey regions). Panel B and E: the ground true segmentations of lesions in panel A and D. Panel C and F: the predictions by U-Net model of the lesions in panel A and D. A scale bar representing 500 μm is shown in each panel.

Abstract Figure
P1382Extended long-term follow-up of radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (first versus second generation cryoballoon)
Authors: Kettering K
Published: June 2020

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation. Cryoablation has been shown to be a safe and effective technique for pulmonary vein isolation. However, there is a significant arrhythmia recurrence rate after cryoablation procedures and there are no established strategies for redo procedures in these patients. Therefore, we have summarized our experience with radiofrequency catheter ablation for redo procedures after pulmonary vein isolation with the cryoballoon technique (including an analysis of pulmonary vein conduction recovery patterns ater procedures performed with the first or second generation cryoballoon).

Methods

One hundred and twenty patients (paroxysmal AF: 78 patients, persistent AF: 42 patients) had to undergo a redo procedure after initially successful circumferential PV isolation with the cryoballoon technique. The redo ablation procedures were performed using a segmental approach or a circumferential ablation strategy depending on the intra-procedural findings.

Results

During the redo procedure, a mean number of 1.8 re-conducting PVs were detected (using a circular mapping catheter; group A: 2.1 re-conducting PVs, group B: 1.5 re-conducting PVs). There was a slightly higher incidence of chronic PV reconnections related to the left-sided PV ostia than to the right-sided PVs in both groups. Furthermore, sites of chronic PV reconnection were found more frequently in the inferior parts of the PV ostia than in the superior parts. In 53 patients in group A, a segmental approach was sufficient to eliminate the residual PV conduction because there were only a few recovered PV fibers (1-3 reconnected PVs; group A1). In the remaining 7 patients in group A, a circumferential ablation strategy was used because of a complete recovery of the PV-LA conduction of all four pulmonary veins (group A2). In group B, a segmental approach was sufficient in all patients because there was only a minor  reconnection of 1-2 PVs.

All recovered PVs could be isolated sucessfully again. At 42-month follow-up, 78 % of all patients were free from an arrhythmia recurrence (94/120 patients; group A: 43/60 patients (71 %), group B: 51/60 patients (85 %)). There were no major complications in both groups.

Conclusions

In patients with an initial circumferential PVI using the cryoballoon technique, a repeat ablation procedure can be performed safely and effectively using radiofrequency catheter ablation. In most cases only a few re-conducting PV fibers were found and therefore, a segmental re-ablation approach seems to be sufficient in the majority of patients (especially in patients treated with the second generation cryoballoon).
P1457Does high density mapping increase the efficacy of ischemic ventricular tachycardia ablation?
Authors: Nunes Ferreira A , Silva G , Cortez-Dias N , Silverio-Antonio P , Rodrigues T , Aguiar-Ricardo I , Santos R , Sobral S , Barreiros C , Carpinteiro L , Pinto F J , De Sousa J
Published: June 2020

Introduction

 The treatment of ventricular tachycardia (VT) in patients (pts) with ischemic heart disease (IHD) represents a challenge because of its high morbidity and mortality rates and low long-term success rates. In the VANISH clinical trial, 51% of pts undergoing the conventional ablation technique developed within 2 years the combined outcome of mortality or electrical storm (ES) or appropriate CDI shock. The use of high-density substrate maps can lead to greater precision in substrate evaluation and ideally to improved ablation success.

Objectives

 To assess the efficacy of substrate-guided ischemic VT ablation using high-density mapping.

Methods

 Single-center prospective study of consecutive IHD pts submitted to endocardial ablation of substrate-guided VT using multipolar catheters (PentaRayTM or HDGridTM) and three-dimensional mapping systems with automatic annotation software. The maps were evaluated in order to identify the intra-cicatricial channels (areas of bipolar voltage <1.5mV) in which sequential propagation of local abnormal ventricular activities (LAVAs) were observed, during or after QRS. The ablation strategy aimed at the abolition of all intra-cicatricial LAVAs, directing the radiofrequency applications primarily to the entrances of the channels. The success of ablation was assessed by the primary outcome (death by any cause or ES or appropriate CDI shock) at 2 years and compared to the population of the VANISH study undergoing conventional ablation, using Cox regression and Kaplan- Meier survival analysis.

Results

 We included 40 patients, 95% males, 70 ± 8 years, mean ejection fraction 34 ± 10%. 82% on previous amiodarone therapy and 72% were ICD carriers. 32% underwent ablation during hospitalization for ES and 20% had previously undergone VT ablation. The median duration of substrate mapping was 74 minutes, with a mean of 2290 collected points. Major complications were seen in 1 patient (aortic dissection). During a mean follow-up time of 17.3 ± 12.9 months, the long-term success rate of VT ablation was 75%. Additionally, there was a reduction in the proportion of patients receiving amiodarone before vs after ablation (82% vs. 45% respectively). The rate of events observed during follow-up was lower than expected, namely by comparison with the population of the VANISH study undergoing conventional ablation (25% vs 51% at 24 months, HR 0.42 CI 95% 0.2-0.88, p = 0.022), reflecting a relative risk reduction of 58%.

Conclusions

 High density mapping allows a detailed characterization of the dysrhythmic substrate in patients with VT in an IHD context. Our results suggest that these technological innovations may be improving the clinical success of VT ablation.

Abstract Figure.
P1375Catheter ablation of atrial fibrillation: three-dimensional transesophageal echocardiography versus magnetic resonance imaging for pulmonary vein imaging (periprocedural results and long-term follow-u
Authors: Kettering C
Published: June 2020

Catheter ablation has become the first line of therapy in patients with symptomatic, recurrent, drug-refractory atrial fibrillation (AF). However, it is still challenging because of the high degree of variability of the pulmonary vein (PV) anatomy. Three-dimensional transesophageal echocardiography (TEE) is a promising new technique for cardiac imaging. Therefore, we have evaluated the usefulness of 3-D TEE for analysing the left atrial anatomy prior to an ablation procedure in comparison to magnetic resonance imaging (MRI).

Methods

In 120 patients, 3-D TEE and cardiac MRI were performed immediately prior to an ablation procedure (paroxysmal AF: 50 patients, persistent AF: 70 patients). The image quality provided by 3-D TEE and by cardiac MRI was compared in all patients. Two different ablation strategies were used. In patients with paroxysmal AF, the cryoablation technique was used. In the other patients, a circumferential pulmonary vein ablation was performed using a three-dimensional mapping system.

Results

A 3-D TEE and a cardiac MRI could be performed successfully in all patients prior to the ablation procedure. Several variations of the PV anatomy could be visualized precisely by 3-D TEE and cardiac MRI (e.g. accessory PVs, common PV ostia, varying diameter of the left atrial appendage and its distance to the left superior PV). The image quality was good in the majority of patients even if AF with rapid ventricular response was present during the examination. The image quality provided by 3-D TEE was acceptable in 116/120 patients (96.7 %). The TEE findings correlated well with the PV angiographies performed using cardiac MRI. There was a good correlation with regard to the diameter of the PV ostia assessed by these two imaging techniques. All ablation procedures could be performed successfully (mean number of completely isolated PVs: 3.9  (cryo group), 4.0 (radiofrequency catheter ablation group)). At 42-month follow-up, 70.0 % of all patients were free from an arrhythmia recurrence (cryo group: 76.0 %, Carto group: 65.7 %). There were no major complications.

Conclusions

AF ablation procedures can be performed safely and effectively based on prior 3-D TEE imaging. The image quality was acceptable in the vast majority of patients.
P313The automatically assessed P-wave axis predicts cardiovascular events in patients with cardiovascular risks: The Japan Morning Surge Home Blood Pressure (J-HOP) Study
Authors: Kabutoya T , Hoshide S , Kario K
Published: June 2020

Background

An abnormal P-wave axis in electrocardiography predicts the development of atrial fibrillation (AF) and cardiovascular events. There have been few reports on the relationships among an automatically assessed P-wave duration, left atrial enlargement, left ventricular hypertrophy, and cardiovascular events in patients with cardiovascular risk factors. 

Purpose

To determine the relationship among an abnormal P-wave axis,  left atrial enlargement, left ventricular hypertrophy, and cardiovascular events in patients with cardiovascular risk factors. 

Methods

We enrolled 829 subjects from the J-HOP Study who had ≥1 of four cardiovascular risk factors: hypertension, dyslipidemia, diabetes, and smoking. Twelve-lead electrocardiography was conducted, and the P-wave axis was calculated automatically using a 12-lead ECG Analysis system (Fukuda Denshi, Tokyo) according to the following formula: arctan{√3(II + III) / (2I + II-III)}. We divided the patients into three groups: those with a normal axis (0°–75°, n = 692), left axis deviation (<0°, n = 39), or right axis deviation (≥75°, n = 56). The primary endpoints were fatal/nonfatal cardiovascular events: myocardial infarction, stroke, hospitalization for heart failure, and aortic dissection. We conducted echocardiography and measured the left atrial (LA) diameter, left ventricular mass index (LVMI), and brain natriuretic peptide (BNP). 

Results

The LA diameter, LVMI, and BNP in the patients with left axis deviation were significantly higher than those in the patients with a normal axis (LA diameter: 40.2 ± 7.0 vs. 37.0 ± 5.0, p = 0.008; LVMI: 105.7 ± 25.7 vs. 96.9 ± 25.2 g/m2, p < 0.001; median BNP: 41.6 vs. 16.5 pg/dL, p < 0.001). The mean follow-up period was 101 ± 34 months, and 92 cardiovascular events occurred. A Cox proportional hazards model including age, gender, smoking, history of hypertension, dyslipidemia, diabetes, LA dia., and LVMI revealed that left axis deviation of the P wave was independently associated with cardiovascular events (hazard ratio 2.31, 95%CI 1.18–4.55, p = 0.015). Conclusions: Leftward deviation of the automatically assessed P-wave axis was associated with left atrial enlargement, left ventricular hypertrophy, and cardiovascular events in patients with cardiovascular risk.
P1360Association between left atrial appendage dysfunction and thromboembolic risk in nonvalvular atrial fibrillation
Authors: Mao Y , Ma M M , Yu C , Yang Y , Wang Y H , Jiang C Y
Published: June 2020

Background/Introduction:  Atrial fibrillation (AF) is associated with higher risk for thromboembolism , and the discriminative ability of the widely used CHA2DS2-VASc scores for risk stratification is modest. Although the presence of thrombus in the LAA is the most powerful predictors for thromboembolic risk, they are often absent in patients with AF and prior stroke. AF may be related to myocardial fibrosis, and even though left atrial fibrosis is associated with mechanical dispersion, this phenomenon is not well studied in LAA. We hypothesized that detection of LAA dysfunction and mechanical dispersion using strain echocardiography is useful in the identification of cardiac thromboembolism.

Purpose

The aim of this study was to determine the association of LAA mechanics assessed using strain analysis with previous thromboembolic events in patients with nonvalvular AF and to assess the potential incremental significance of LAA mechanical dispersion over the traditional risk stratification scheme.

Methods

A group of 116 patients with AF referred for TEE was prospectively analyzed. LAA strain and mechanical dispersion in parallel with other conventional TEE parameters were analyzed in terms of their association with previous embolic stroke and peripheral embolization.

Results

Patients with embolic events had a higher mean CHA2DS2-VASc score, higher incidence of LAA dense SEC or thrombi, and other clinical data were comparable. Patients with embolic events had greater impairment in the LA standard parameters, and lower global and regional LAA longitudinal strain than those of the controls. LAA MD was significantly higher in patients with embolization than in those without it (18.91 ± 7.19 %vs 13.8 ± 5.54%; P < .001). In ROC analysis, cut-off values for LAA MD,LAEF, LAA GLS for the presence of dense SEC/ thrombus were >20.21 % (p = 0.0076), ≤31.11 % (p = 0.017), and ≤ 7.31 % (p = 0.014), respectively. LAA MD, LAEF, LAA thrombus and CHA2DS2-VASc scores were independently associated with the presence of thromboembolism in multivariate analyses, and LAA MD had additional significance over the CHA2DS2-VASc score.

Conclusion

LAA MD, LAA thrombi and LAEF had statistically significant meaning for the presence of prior embolism that was independent of the standard planimetric and volumetric measurements. What’s more, LAA MD had an incremental value over CHA2DS2-VASc score in risk stratification and warrants testing in a larger study.

Abstract Figure. ROC curves for LAA parameters
P456Ultrasound guidance for femoral venous access in patients undergoing pulmonary vein isolation: a quasi-randomized study
Authors: Kupo P , Pap R , Bencsik G , Kohari M , Benak A , Miklos M , Saghy L
Published: June 2020

Background

The most common complications of electrophysiology (EP) procedures are related to vascular access.

Purpose

Our study aimed to compare the ultrasound (US)-guided (Group 1) vs. palpation-based (Group 2) technique for femoral venous access in atrial fibrillation (AF) ablation procedures.

Methods

Between January 2018 and October 2019, 355 patients undergoing pulmonary vein isolation (PVI) on uninterrupted anticoagulant treatment were included. They were allocated to Group 1 or 2 based on which of the two procedure rooms their procedure was scheduled in, with only one of the rooms equipped with an US machine including an 8 MHz linear transducer. Major and minor complications and the rate of prolonged hospitalization were compared in the two groups. Major vascular complication was defined as groin hematoma, arteriovenous fistula, or pseudoaneurysm. Hematoma was considered as a major vascular complication if it met type 2 or higher Bleeding Academic Research Consortium (BARC) criteria (requiring nonsurgical, medical intervention by a health care professional; leading to hospitalization or increased level of care, or prompting evacuation).

Results

Of the 355 patients 105 were allocated to Group 1 and 250 included in Group 2. Compared to the standard technique, the use of US significantly reduced both major (from 5.60% to 0.95%, p = 0.047) and minor (from 6.40% to 0.95%, p = 0.029) vascular complications. The absolute risk reduction (ARR) of minor/major vascular complications was 10.10% equated to a relative risk reduction (RRR) of 84.13%, and a number needed to treat (NNT) of 10 to prevent one bleeding event. No difference was found for the rate of prolonged hospitalization (5.04% vs. 0.95%, p = 0.119).

Conclusion

With the use of US for the femoral vein puncture in patients undergoing PVI procedure the rate of both major and minor vascular complications were lower.
P480Aldosterone plasma level as risk factor of ventricular arrhythmias in heart failure with preserved ejection fraction
Authors: Shevelyok A , Vatutin N
Published: June 2020

Background. Sudden cardiac death, one of the most common types of cardiac death, is most often triggered by ventricular arrhythmia. Plasma aldosterone level has been shown to be an independent risk factor of life-threatening ventricular arrhythmia in patients with left ventricular systolic dysfunction following acute myocardial infarction. Whether either effect also occurs in patients with heart failure and preserved ejection fraction (HFpEF) is currently unknown.

Purpose. The study aims to investigate the relationship between plasma aldosterone level and ventricular arrhythmias in long-term HFpEF.

Methods. The study included 158 patients (58 men and 100 women, mean age 62.3 ± 7.4 years) with HFpEF (> 50%). All patients had a history of hospitalization due to HFpEF during the last 12 months, left ventricular diastolic dysfunction and / or elevated NT-proBNP level. Median confirmed HFpEF duration was 5 (range 4-8) years. Patients had no history of primary aldosteronism and did not use the mineralocorticoid receptor antagonists during the last 6 weeks. Aldosterone plasma level was measured and 24-hour electrocardiographic monitoring was performed.

Results. According to laboratory results 99 patients (67.1%, 95% confidence interval (CI) 59.6-74.2%) had normal (40-160 pg/ml) aldosterone plasma level (nAld) and 59 patients (37.3%, 95% CI  30.0-45.0%) had high (> 160 pg/ml) aldosterone level (hAld). hAld patients more often had QTc prolongation (44.1% versus 18.2%) and ventricular arrhythmias (83.1% vs 61.6%) compared to nAld patients (all Ps < 0.001). The number of ventricular premature complexes in 24 hours was higher in hAld group (median 214, range 64-758) compared to nAld (median 52, range 16-198, P < 0.003). hAld patients more often occurred bigemy, couple ventricular ectopy and nonsustained ventricular tachycardia (39.0% vs 19.0%, P = 0.01). In Cox regression models high aldosterone plasma level was the independent risk factors of QTc prolongation (odds ratio (OR) 1.6, 95% CI 1.1-5.7, P = 0.034) and prognostically unfavorable ventricular arrhythmias (OR 1.8, 95% CI 1.2-6.8, P = 0.024).

Conclusion. In long-term HFpEF plasma aldosterone level is significantly related to QTc prolongation as well as ventricular arrhythmias.
P378Heart rhythm disorders in Acromegaly
Authors: Melkozerov K , Przhiyalkovskaya E , Tarbaeva N , Kalashnikov V , Belaya Z , Vorontsov A , Belousov L , Alferova P
Published: June 2020

Aim

to evaluate the prevalence of heart rhythm disorders among hospitalized patients with acromegaly

Methods

we enrolled patients with acromegaly hospitalized in our Endocrinology Research Center in 2018. Acromegaly was established based on the clinical signs and symptoms, elevated levels of insulin-like growth factor-1 (IGF-1) and presence of pituitary adenoma. All patients underwent clinical examination, routine electrocardiogram (ECG). In patients with changes in the resting ECG and/or complaints of heart rhythm disorders, echocardiography and Holter ECG monitoring were performed. We also performed cardiac magnetic resonance imaging (MRI) with contrast in cases of arrhythmia confirmation.

Results

Among 107 enrolled patients with acromegaly (61 women, mediana of age 51 [40; 58] years) arrhythmia was first diagnosed in 21 (19,6%) patients: 7 patients had sick sinus syndrome, 5 patients suffered from atrial fibrillation, 4 patients had AV block, 5 patients - ventricular arrhythmias (1 patient had sustained ventricular tachycardia). The median level of the GH was 1,77 [0,8; 5,4] ng/ml, and the median of IGF-1 - 348,95 [233,4; 557,4] ng/ml, 16 (76,1%) patients with arrhythmia had active acromegaly. 21 patients underwent MRI of the heart: median of ejection fraction 54 [48; 60] %, in 8 patients we revealed focal fibrosis of left ventricle myocardium. Diffuse accumulation of contrast agent was observed in 11 patients of different severity and localization, mainly endocardium of mitral and tricuspid valves. We didn’t find a clear correlation between the levels of hormones, changes in the MRI of the heart and the type of cardiac arrhythmia. We implanted pacemakers in 4 patients, 1 patient – implantable cardioverter defibrillator.

Conclusion

The prevalence of cardiac arrhythmia in hospitalized patients with acromegaly is about 20%. New cases of arrhythmia could occur despite normal level of GH and IGF-1 in patients with acromegaly. Patients with acromegaly and cardiac arrhythmia often have abnormalities in MRI of the heart, which requires further investigation.
P1077Late gadolinium enhancement with cardiac magnetic resonance imaging demonstrates left ventricular involvement is under-recognized in arrhythmogenic right ventricular cardiomyopathy
Authors: Mohamed S , Kunz M , Casey S , Katsiyiannis W , Abdelhadi R , Storey K , Berg A , Schmidt C , Sengupta J
Published: June 2020

Funding Acknowledgements

The study is partially funded by Medtronic and the Minneapolis Heart Institute Foundation.

Background/Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by replacement of the myocardium with fibrous and fatty tissue that may lead to an increased risk of ventricular arrhythmias and heart failure.  Although left ventricular (LV) and biventricular forms have been identified post-mortem resulting in the increased use of the term arrhythmogenic cardiomyopathy, there is only inclusion of right ventricular wall motion abnormalities in the taskforce diagnostic criteria.

Purpose

The aim of our study was to examine the utility of cardiac magnetic resonance (CMR) imaging in characterizing LV or biventricular involvement with late gadolinium enhancement (LGE) in a large cohort of patients with suspected ARVC.

Methods

Retrospective, single-institution, chart review of 76 patients diagnosed with ARVC between January 2009 and July 2019. Data collection and analysis included baseline demographics and parameters specific to diagnosis (definite, borderline, or possible) and risk stratification of ARVC based on 2019 modified taskforce criteria, as well as detailed CMR evaluation.

Results

Of the 76 patients with ARVC, 66 (87%) had at least one CMR with gadolinium administered. In that subset of patients, 27 (41%) had LGE. Of those with LGE, LV involvement was identified in 23 (85%) patients. The pattern of LGE was not localized to one myocardial region but demonstrated variable LV enhancement patterns including anterior, inferior, lateral, septal, basal, mid, apical, and from the sub-epicardium into the mid-myocardium.

Conclusions

  Left ventricular involvement reflected by LGE was identified in a high percentage of patients with suspected ARVC, and there was significant variation in the pattern of distribution in terms of region and depth of myocardial involvement.  While post-mortem examination of patients with ARVC demonstrates a high prevalence of left ventricular involvement, this study shows that CMR can consistently detect late gadolinium enhancement, and ARVC should be considered in the differential diagnosis for biventricular cardiomyopathy.  The identification of variable locations of LGE within the LV suggests there is more than one phenotype, and this imaging modality may help to clarify the implications of left ventricular involvement in disease progression.
P506Brugada Syndrome: is the addition of the electrocardiographic risk markers the clue?
Authors: Tronconi A , Carnero G , Mysuta M , Bozza A , Peltzer M , Labin B , Gavilan L , Ramirez D , Alvarez M , Gonzalez J L , Galizio N
Published: June 2020

Background

Risk stratification in Brugada Syndrome (BS) remains a clinical challenge. Several electrocardiografic (ECG) risk markers had been described, as a spontaneous type 1 Brugada pattern (ST1B), maximal time interval between the peak and the end of the t wave in precordial leads (Tpe Max), the presence of an S Wave on DI, a PR interval (PRi) ≥ 200ms and fragmented QRS (f-QRS).

Purpose

Evaluate the association of ECG risk markers with sudden cardiac death (SCD) or appropriate shocks (A-Sh) by implantable cardioverter defibrillator (ICD) in patients (p) with BS.

Methods

From a registry of 97 p with BS with a median follow up of 2.3 years (Q1 0.7-Q3 7.8), 12 lead ECG were recorded in every p. QT peak interval (QTp) was measured between the QRS onset and the peak of the T wave. Tpe was calculated between the difference of QT and QTp in precordial leads (V1 to V6). TpeMax was defined as the most prolonged Tpe. If an S-DI was present, duration and amplitude was measured. PRi was measured on DII. Baseline characteristics: Age 44 ± 13 years, male 74 (76%), secondary prevention 2 (3%), malignant syncope 10 (10%), inducible electrophysiology study 22/43 (51%), SCD on first grade family < 35 years 12 (12%) and ICD 34 (35%). A-Sh and SCD were compared among p with ST1B vs no ST1B, TpeMax≥100 vs <100ms, S-DI ≥0.4 vs <0.4ms, S-D ≥0.1 vs <0.1mV, PRi≥200 vs <200ms and presence of f-QRS ≥ 2 spike ≥ 2 leads. Variables that were associated with A-Sh or SCD were combined. For variables with significant difference sensibility (Sen) and specificity (Spe) was calculated.

Results

During follow up 6 p presented A-Sh and no p SCD. Results are described in the Table.

Conclusion

In our study population, there was a significant higher incidence of A-Sh in p with ST1B, Tpe Max ≥ 100ms and S-DI ≥ 0.1mV. We found that the presence of one ECG risk marker had a high sensibility to predict A-Sh. The presence of the 3 ECG risk markers highly increased specificity to predict A-Sh. Further trials should be carried out to asses if ECG risk markers would allow us to differentiate which asymptomatic patients could benefit from electrophysiological study for risk stratification (high sensibility - One ECG Risk marker) or would benefit from ICD implantation (high specificity - 3 ECG Risk markers).

Abstract Figure.
P355Complete non-inducibility after radiofrequency ablation for electrical storm improves survival rates
Authors: Nastasa A , Cojocaru C , Radu D A , Goanta E , Iliese V , Badiu A , Bogdan S N , Iorgulescu C N , Dorobantu M , Vatasescu R G
Published: June 2020

Background

Electric storm is a life threatening condition, that can complicate multiple cardiac pathologies and is associated with high mortality.  Catheter ablation has been shown to reduce ventricular tachycardia (VT) burden in patients with electrical storm but the optimal procedural endpoint and the therapeutic particularities required by different etiologies are still under debate.

Purpose

Our objective was to determine if there are any periprocedural factors that influence midterm outcomes.  We also sought if there were any significant differences between the results for ischemic and nonischemic patients.

Methods

The study included 66 consecutive patients, mean age 60 years, 82% males, treated for electrical storm in our center with endocardial/endo-epicardial radiofrequncy catheter ablation (with or without remote magnetic navigation). Acute success was defined as elimination of the clinical tachycardia with complete non-inducibility (including ventricular fibrillation) or non-inducibility for monomorphic VT with programmed ventricular stimulation using up to 4 extrastimuli. Mean follow-up duration was 9.4 months and the type of recurrence was catalogued in 3 categories: initial VT (isolated), electric storm and other sustained VT.

Results

The overall acute success rate was 93%, complete non-inducibility was achieved in 64.5% and non-inducibility for monomorphic VT in 87.5% of the cases. Epicardial approach was used in 44% of the non-ischemic cases vs 10.5% of the ischemic ones (p = 0.005). There were no significant differences between complete noninducibility rates and recurrence/death rates of the ischemic vs nonischemic groups. Among the variables analysed for predicting noninducibility, only two reached statistical significance: mean QRS duration of the clinical tachycardia (160 ± 32 ms vs 240 ± 63.3ms, p = 0.02) and shortest RS complex (124 ± 14.7 ms vs 210 ± 12ms, p = 0.02). Recurrent ventricular arrhythmia occurred in 25% of the patients during follow up, from which: 27.2 % initial VT (isolated), 36.4% electric storm and 36.4% other sustained VT. Death rate was 10.6% (7 patients).  Kaplan Meier plot showed that the lot with complete noninducibility after programmed ventricular stimulation had better survival rates (p = 0.01).

Conclusions

Ablative therapy had a good acute success rate, without significant differences between ischemic and noninschemic patients in our study. Complete noninducibility after programmed ventricular stimulation  after ablation was associated with better survival rates. Unsuccessfull ablation is a predictor of inhospital death of these patients.
244An automated beat exclusion algorithm to improve beat-to-beat P-wave morphology analysis
Authors: Tachmatzidis D , Filos D , Chouvarda I , Tsarouchas A , Mouselimis D , Bakogiannis C , Antoniadis A , Fragkakis N , Maglaveras N , Vassilikos V
Published: June 2020

Background

A manually beat-to-beat P-wave analysis has previously revealed the existence of multiple P-wave morphologies in patients with paroxysmal Atrial Fibrillation (AF) while on sinus rhythm, distinguishing them from healthy, AF free patients.

Purpose

The aim of this study was to investigate the effectiveness of an Automated Beat Exclusion algorithm (ABE) that excludes noisy or ectopic beats, replacing manual beat evaluation during beat-to-beat P-wave analysis, by assessing its effect on inter-rater variability and reproducibility.

Methods

Beat-to-beat P-wave morphology analysis was performed on 34 ten-minute ECG recordings of patients with a history of AF. Each recording was analyzed independently by two clinical experts for a total of four analysis runs; once with ABE and once again with the manual exclusion of ineligible beats. The inter-rater variability and reproducibility of the analysis with and without ABE were assessed by comparing the agreement of analysis runs with respect to secondary morphology detection, primary morphology ECG template and the percentage of both, as these aspects have been previously used to discriminate PAF patients from controls.

Results

Comparing ABE to manual exclusion in detecting secondary P-wave morphologies displayed substantial (Cohen"s k = 0.69) to almost perfect (k = 0.82) agreement. Area difference among auto and manually calculated main morphology templates was in every case <5% (p < 0.01) and the correlation coefficient was >0.99 (p < 0.01). Finally, the percentages of beats classified to the primary or secondary morphology per recording by each analysis were strongly correlated, for both main and secondary P-wave morphologies, ranging from ρ=0.756 to ρ=0.940 (picture)

Conclusion

The use of the ABE algorithm does not diminish inter-rater variability and reproducibility of the analysis. The primary and secondary P-wave morphologies produced by all analyses were similar, both in terms of their template and their frequency. Based on the results of this study, the ABE algorithm incorporated in the beat-to-beat P-wave morphology analysis drastically reduces operator workload without influencing the quality of the analysis.

Abstract Figure.
P1451Catheter ablation in adults with Wolff-Parkinson-White syndrome: a "real-life" experience
Authors: Ying A , C L S D Nubila B , Divulwewa K , Agarwal S , Begley D , Grace A , Heck P , Martin C , Mellor G , Virdee M , Fynn S
Published: June 2020

Introduction. Radiofrequency catheter ablation (RFA) is 1st line treatment in symptomatic adult patients with Wolff-Parkinson-White syndrome (WPW). Patients with WPW are often quoted a high success rate for RFA but does this reflect reality? There is a paucity of recent literature and ongoing service developments in the UK may have a negative impact on success by reducing individual operator experience of adult WPW cases (i.e. increasing numbers of cardiac electrophysiologists in each department, patients more likely to undergo RFA as children). In contrast, technological developments (e.g. 3D mapping, steerable sheaths) may have a positive impact on success of RFA in WPW.

Methods. We collected data on all patients with WPW scheduled for 1st time ablation between Jan 2006 and Dec 2018. All patients undergoing re-do RFA during this time were excluded. For comparison, we divided this timeframe into three periods: 2006-9, 2010-13 and 2014-18.

Results. The number of patients scheduled for RFA and the outcome is listed in the Table. The overall success rate was 86.5% and this figure remained constant throughout the 13 year time-frame. Significant complications occurred in 1.17% of cases. 19.9% of patients scheduled for an ablation had no ablation attempted for various reasons (‘safe’ pathway, proximity to AV node etc).

Conclusion. In our centre, the number of adult cases of WPW scheduled for RFA year-on-year remains constant. The complication rate is in line with published literature. The RFA success rate is lower than the published data. As expected, success rate of RFA for WPW varies according to accessory pathway location. 1 in 5 cases scheduled for ablation did not proceed to ablation. This highlights an area where more effective resource planning from the outset can be undertaken.

Table 2006-9 2010-13 2014-18 Patients scheduled for RFA, n 181 152 179 Patients who underwent RFA, n 162 121 127 Overall RFA success rate, % (n) 85.6 (160) 86.6 (119) 87.4 (127) Success rate by AP location, % (n) Free wall Left 91.5 (71) 91.8 (49) 95.3 (64) Right 76.9 (13) 77.8 (9) 60.0 (5) Septal Anterior 77.8 (9) 88.9 (9) 100.0 (4) Mid 75.0 (8) 90.0 (10) 66.7 (3) Posterior 86.0 (57) 82.9 (41) 79.6 (49) RFA success rate in patients with Wolff-Parkinson-White syndrome. AP = accessory pathway, RFA = radiofrequency catheter ablation