{"title":"The Influence of Cardiac Ablation on the Electrophysiological Characterization of Rat Isolated Atrium: Preliminary Analysis","authors":"J. Paredes, S. Pollnow, O. Dössel, J. Salinet","doi":"10.22489/CinC.2020.265","DOIUrl":"https://doi.org/10.22489/CinC.2020.265","url":null,"abstract":"Atrial fibrillation (AF) is the most common cardiac arrhythmia seen in clinical practice and its treatment by antiarrhythmic drugs is still non-effective. Radiofrequency catheter ablation (RFA) has been widely accepted as a strategy to prevent AF by creating myocardial lesions to block the AF electrical wavefront propagation and eliminate arrhythmogenic tissue. In this study, we analyzed the electrophysiological impact of different RFA time duration strategies through a controlled animal protocol. Electrical activity of the isolated right atrium of rats, under different RFA time strategies on the epicardium, was acquired during 4 s on the endocardium by electrical Mapping (EM) and simultaneously on the endocardium by Optical Mapping (OM), respectively. Analyses were concentrated on both time and frequency domain, through analysis of sig-nal's morphology, local activation time, conduction velocity, dominant frequency (DF), and organization index (OI). The morphology of the optical and electrical signals was altered as the ablation time increased, making it difficult to identify activation times. Moreover, DF and OI decreased with increasing ablation time implied in fragmented electrograms. Through the characterization of traditional metrics applied to the electrical and optical data, it was possible to identify important changes, in time and frequency, inside the ablated regions.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123769467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seonwoo Min, Hyun-Soo Choi, Hyeongrok Han, Minji Seo, Jinkook Kim, Junsang Park, Sunghoon Jung, I. Oh, Byunghan Lee, Sungroh Yoon
{"title":"Bag of Tricks for Electrocardiogram Classification With Deep Neural Networks","authors":"Seonwoo Min, Hyun-Soo Choi, Hyeongrok Han, Minji Seo, Jinkook Kim, Junsang Park, Sunghoon Jung, I. Oh, Byunghan Lee, Sungroh Yoon","doi":"10.22489/CinC.2020.328","DOIUrl":"https://doi.org/10.22489/CinC.2020.328","url":null,"abstract":"Recent algorithmic advances in electrocardiogram (ECG) classification are largely contributed to deep learning. However, these methods are still based on a relatively straightforward application of deep neural networks (DNNs), which leaves incredible room for improvement. In this paper, as part of the PhysioNet / Computing in Cardiology Challenge 2020, we developed an 18-layer residual convolutional neural network to classify clinical cardiac abnormalities from 12-lead ECG recordings. We focused on examining a collection of data pre-processing, model architecture, training, and post-training procedure refinements for DNN-based ECG classification. We showed that by combining these refinements, we can improve the classification performance significantly. Our team, DSAIL_SNU, obtained a 0.695 challenge score using 10-fold cross-validation, and a 0.420 challenge score on the full test data, placing us 6th in the official ranking.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126800128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yingjing Feng, C. Roney, M. Hocini, S. Niederer, E. Vigmond
{"title":"Robust Atrial Ectopic Beat Classification From Surface ECG Using Second-Order Blind Source Separation","authors":"Yingjing Feng, C. Roney, M. Hocini, S. Niederer, E. Vigmond","doi":"10.22489/CinC.2020.473","DOIUrl":"https://doi.org/10.22489/CinC.2020.473","url":null,"abstract":"Ectopic beats (EBs) generated from the atria or pulmonary veins are an important trigger mechanism for atrial fibrillation (AF). They can be periodic, and have been commonly observed during AF episodes. Robust noninvasive detection of EBs could improve pre-operative prediction, as well as post-ablation management. By separating periodic sources from surface ECG using second-order blind source separation methods, EBs were extracted, and discriminated from AF reentries, another type of periodic source. Our method is robust to noise of up to 0.5mV in the ECG, achieving an area-under curve of receiver operating characteristic (AUC-ROC) of 0.89±0.01 over a synthetic dataset of 31 reentries and 58 EBs, with and without Acetylcholine modulation in the left atrium.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122515900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Jacobs, Amalia Villa Gómez, Jonathan Moeyersons, S. Huffel, R. Willems, C. Varon
{"title":"Can Laplacian Eigenmaps Be Used for Differentiation Between Healthy Subjects and Patients With Corrected Tetralogy of Fallot?","authors":"B. Jacobs, Amalia Villa Gómez, Jonathan Moeyersons, S. Huffel, R. Willems, C. Varon","doi":"10.22489/CinC.2020.119","DOIUrl":"https://doi.org/10.22489/CinC.2020.119","url":null,"abstract":"Tetralogy of Fallot (ToF) is a congenital structural heart disease. While early diagnosis and corrective surgery allow most patients to live normal lives, some patients slowly deteriorate. The current inability to quantify the deterioration and predict these events prompts a data driven approach. Laplacian Eigenmaps (LEs) are a dimensionality reduction technique that can be used to project multi-lead ECGs onto a lower dimensional space. This pilot study aims to evaluate the ability of LEs to characterize deterioration of ToF patients. A general LE model is constructed, based on the 12-lead ECG recordings of 20 healthy controls. A set of distance metrics are developed to quantify the overall changes between different ECG recordings within this LE model. Statistically significant differences between control and ToF subjects were observed for most of the distance metrics. The analysis of changes over time in ToF patients indicates a general trend of increased distance over time in all the metrics, which can be related to a worsening condition. This indicates the relevance of LEs in multi-lead ECG processing, particularly for deterioration analysis.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122642877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Moccia, A. Cagnoli, C. Martini, Giuseppe Moscogiuri, M. Pepi, E. Frontoni, G. Pontone, E. Caiani
{"title":"A Novel Approach Based on Spatio-temporal Features and Random Forest for Scar Detection Using Cine Cardiac Magnetic Resonance Images","authors":"S. Moccia, A. Cagnoli, C. Martini, Giuseppe Moscogiuri, M. Pepi, E. Frontoni, G. Pontone, E. Caiani","doi":"10.22489/CinC.2020.050","DOIUrl":"https://doi.org/10.22489/CinC.2020.050","url":null,"abstract":"Aim. To identify the presence of scar tissue in the left ventricle from Gadolinium (Gd)-free magnetic resonance cine sequences using a learning-based approach relying on spatiotemporal features. Methods. The spatial and temporal features were extracted using local binary patterns from (i) cine end-diastolic frame and (ii) two parametric images of amplitude and phase wall motion, respectively, and classified with Random Forest. Results. When tested on 328 cine sequences from 40 patients, a recall of 70% was achieved, improving significantly the classification resulting from spatial and temporal features processed separately. Conclusions. The proposed approach showed promising results, paving the way for scar identification from Gd-free images.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122908078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Margara, Z. Wang, A. Bueno-Orovio, B. Rodríguez
{"title":"Human Ventricular Modelling and Simulation of Drug Action on Electrophysiology and Contraction","authors":"F. Margara, Z. Wang, A. Bueno-Orovio, B. Rodríguez","doi":"10.22489/CinC.2020.386","DOIUrl":"https://doi.org/10.22489/CinC.2020.386","url":null,"abstract":"Drug safety and efficacy assessment remains as one of the biggest challenges in both preclinical and clinical drug development. Cardiac adverse outcomes may emerge even though they did not occur in early stages of drug development. Among them, the prediction of drug action on cardiac contraction and electrophysiology is especially complex. Human in-silico drug trials constitute a powerful methodology for their investigation and can integrate and augment biophysically detailed experimental information. In this study, we present an integrated modelling and simulation framework for the simultaneous assessment of electrophysiological and contractile effects of drug action in human cardiac function. We analyse both pure potassium and calcium channels blockers, given their prevailing use in clinical practice. Simulation results demonstrate the positive inotropic effect of potassium blockers, with the potential occurrence of contractile abnormalities triggered by repolarisation abnormalities, and the dose-dependent negative inotropic effect of calcium blockers. This study demonstrates the translational and preclinical potential of human-based in-silico drug trials to investigate drug-induced effects on human cardiac electromechanical function.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122913811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Edison F. Carpio, J. Gomez, José F. Rodríguez-Matas, B. Trénor, José M. Ferrrero
{"title":"Computational Analysis of Vulnerability to Reentry in Acute Myocardial Ischemia","authors":"Edison F. Carpio, J. Gomez, José F. Rodríguez-Matas, B. Trénor, José M. Ferrrero","doi":"10.22489/CinC.2020.241","DOIUrl":"https://doi.org/10.22489/CinC.2020.241","url":null,"abstract":"The influence of each ischemic component (hypoxia, hyperkalemia, and acidosis) on arrhythmogenesis is controversial and difficult to study experimentally. In the present study, we investigate how the different ischemic components affect the vulnerable window (VW) for reentry using computational simulations. Simulations were performed in a 3D biventricular model that includes a realistic ischemic region and the His-Purkinje conduction system. At the cellular level, we used a modified version of the O’ Hara action potential model adapted to simulate acute ischemia. Three different levels of ischemia were simulated: mild, moderate, and severe. The effects on the width of the VW of each ischemic parameter were analyzed. The model allowed us to obtain a realistic reentrant pattern corresponding to ventricular tachycardia in all simulations. Results suggest that the ischemic level plays an important role in the generation of reentries. Furthermore, hypoxia has the most significant effect on the width of the VW The presence of Purkinje system is key to the generation of reentries.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122976130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Giulia Baldazzi, M. Orrù, M. Matraxia, G. Viola, D. Pani
{"title":"Supervised Classification of Ventricular Abnormal Potentials in Intracardiac Electrograms","authors":"Giulia Baldazzi, M. Orrù, M. Matraxia, G. Viola, D. Pani","doi":"10.22489/CinC.2020.397","DOIUrl":"https://doi.org/10.22489/CinC.2020.397","url":null,"abstract":"Ventricular abnormal potentials (VAPs) identification is a challenging issue, since they constitute the ablation targets in substrate-guided mapping and ablation procedures for ventricular tachycardia (VT) treatment. In this work, two approaches for the supervised classification of VAPs in bipolar intracardiac electrograms are evaluated and compared. To this aim, 954 bipolar electrograms were retrospectively annotated by an expert cardiologist. All signals were acquired from six patients affected by post-ischemic VT by the CARTO3 system at the San Francesco Hospital (Nuoro, Italy) during routine procedures. The first classification approach was based on a support vector machine trained and tested on four different features, extracted from both the time and time-scale domain, to identify physiological and abnormal potentials. Conversely, in order to assess the significance of the first approach and its features, in the second approach all the samples constituting a time-domain segment of each bipolar electrogram were given as input to a feed-forward artificial neural network. In both cases, the accuracy in VAPs and physiological potentials identification exceeded 79%, suggesting their efficacy and the possibility of VAPs automatic recognition without identifying peculiar features.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"239 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114599307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dorien Huysmans, Eva Heffinck, I. Castro, Margot Deviaene, Pascal Borzée, B. Buyse, D. Testelmans, S. Huffel, C. Varon
{"title":"Sleep-Wake Classification for Home Monitoring of Sleep Apnea Patients","authors":"Dorien Huysmans, Eva Heffinck, I. Castro, Margot Deviaene, Pascal Borzée, B. Buyse, D. Testelmans, S. Huffel, C. Varon","doi":"10.22489/CinC.2020.147","DOIUrl":"https://doi.org/10.22489/CinC.2020.147","url":null,"abstract":"Sleep apnea is a common sleep disorder, whose diagnosis can strongly benefit from home-based screening. As the total sleep time is essential to assess the sleep apnea severity, a sleep-wake classifier was developed based on heart rate and respiration. These two signals were selected as they can be measured using unobtrusive sensors. A 1D convolutional neural network (CNN) was designed to classify 30s epochs of tachograms and respiratory inductance plethysmography (RIP) signals. The input based on beat-to-beat variability allows the use of different sensor types. A dataset of 56 patients with an apnea-hypopnea index (AHI) below 10 was used to train and validate the network. This CNN was applied to an independent test set of ECG and RIP signals of 25 subjects. Of these, 8 subjects were simultaneously monitored using an unobtrusive capacitive-coupled ECG (ccECG) sensor integrated in a mattress. Artefact removal and data correction was performed on this acquired data. The performance on the independent dataset of ECG and RIP is comparable to state-of-the-art, with κ = 0.48. However, application on the ccECG data resulted in a drop in performance, with κ = 0.30. This was caused by a low amount of remaining wake epochs after data cleaning. Importantly, the network classified 30s segments of sleep apnea patients, without relying on past or future information for feature extraction.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121839757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Isac N. Lira, Pedro Marinho R. de Oliveira, Walter Freitas, V. Zarzoso
{"title":"Automated Atrial Fibrillation Source Detection Using Shallow Convolutional Neural Networks","authors":"Isac N. Lira, Pedro Marinho R. de Oliveira, Walter Freitas, V. Zarzoso","doi":"10.22489/CinC.2020.385","DOIUrl":"https://doi.org/10.22489/CinC.2020.385","url":null,"abstract":"Atrial fibrillation (AF) is the most frequent sustained arrhythmia diagnosed in clinical practice. Understanding its electrophysiological mechanisms requires a precise analysis of the atrial activity (AA) signal in ECG recordings. Over the years, signal processing methods have helped cardiologists in this task by noninvasively extracting the AA from the ECG, which can be carried out using blind source separation (BSS) methods. However, the robust automated selection of the AA source among the other sources is still an open issue. Recently, deep learning architectures like convolutional neural networks (CNNs) have gained attention mainly by their power of automatically extracting complex features from signals and classifying them. In this scenario, the present work proposes a shallow CNN model to detect AA sources with an automated feature extraction step overcoming the performance of other methods present in the literature.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117089198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}