bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract

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) &lt;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 &lt;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

Abstract

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

Abstract
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

Abstract

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 &lt;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

Abstract
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

Abstract

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 (&lt;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 &lt; 0.001; median BNP: 41.6 vs. 16.5 pg/dL, p &lt; 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

Abstract
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 &lt; .001). In ROC analysis, cut-off values for LAA MD,LAEF, LAA GLS for the presence of dense SEC/ thrombus were &gt;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

Abstract

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

Abstract
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 (&gt; 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 (&gt; 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 &lt; 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 &lt; 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.