D. Borra, Daniela Portas, A. Andalò, C. Fabbri, C. Corsi
{"title":"Performance Comparison of Deep Learning Approaches for Left Atrium Segmentation From LGE-MRI Data","authors":"D. Borra, Daniela Portas, A. Andalò, C. Fabbri, C. Corsi","doi":"10.22489/CinC.2020.306","DOIUrl":"https://doi.org/10.22489/CinC.2020.306","url":null,"abstract":"Quantification of viable left atrial (LA) tissue is a reliable information which should be used to support therapy selection in atrial fibrillation (AF) patients. Late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) is employed for the non-invasive assessment of LA fibrotic tissue. Unfortunately, the analysis of LGE-MRI relies on manual tracing of LA boundaries. This task is time-consuming and prone to high inter-observer variability. Therefore, an automatic approach for LA wall detection would be very helpful. In this study, we compared the performance of different deep architectures - U-Net and attention U-Net (AttnU-Net) - and different loss functions - Dice loss (DL) and focal Tversky loss (FTL) to automatically detect LA boundaries from LGE-MRI data. In addition, AttnU-Net was trained without deep supervision (DS) and multi-scale inputs (MI), with DS and with DS+MI. No statistically significant differences were found training the networks with DL or FTL. U-Net was the best-performing algorithm overall, outperforming significantly AttnU-Net with a Dice Coefficient of 0.9015±0.0308 (mean ± standard deviation). However, no significant differences were found between U-Net and AttnU-Net DS/DS+MI. Based on these results, using a DL or FTL does not affect the performance and U-Net was the best-performing solution.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"13 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":"116782873","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}
Miguel Angel Cámara-Vázquez, Adrián Oter-Astillero, I. Hernández-Romero, Miguel, Rodrigo, Eduardo Morgado-Reyes, S. Guillem, Ó. Barquero-Pérez
{"title":"Atrial Fibrillation Driver Localization From Body Surface Potentials Using Deep Learning","authors":"Miguel Angel Cámara-Vázquez, Adrián Oter-Astillero, I. Hernández-Romero, Miguel, Rodrigo, Eduardo Morgado-Reyes, S. Guillem, Ó. Barquero-Pérez","doi":"10.22489/CinC.2020.383","DOIUrl":"https://doi.org/10.22489/CinC.2020.383","url":null,"abstract":"Atrial fibrillation (AF) is characterized by complex and irregular propagation patterns. Multipoint intracardiac mapping systems present a limited spatial resolution, which makes it difficult to identify AF drivers and ablation targets. These AF onset locations and drivers responsible for AF perpetuation are main targets for ablation procedures. Although noninvasive electrocardiographic imaging (ECGI) and inverse problem-based methods have been tested during AF conditions, they need an accurate mathematical modeling of atria and torso to get good results. In this work, we propose to model the location of AF drivers from body surface potentials (BPS) as a supervised classification problem. We used deep learning techniques to address the problem. We were able to correctly locate the 92% and 96% of drivers in the test and training sets, respectively (accuracy of 0.92 and 0.96), while the Cohen's Kappa was 0.89 for both sets. Therefore, proposed method can help to identify target regions for ablation using a noninvasive procedure as BSP mapping.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"89 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":"114290250","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}
Tomáš Vičar, Jakub Hejc, Petra Novotna, M. Ronzhina, O. Janousek
{"title":"ECG Abnormalities Recognition Using Convolutional Network With Global Skip Connections and Custom Loss Function","authors":"Tomáš Vičar, Jakub Hejc, Petra Novotna, M. Ronzhina, O. Janousek","doi":"10.22489/CinC.2020.189","DOIUrl":"https://doi.org/10.22489/CinC.2020.189","url":null,"abstract":"The latest trends in clinical care and telemedicine suggest a demand for a reliable automated electrocardiogram (ECG) signal classification methods. In this paper, we present customized deep learning model for ECG classification as a part of the Physionet/CinC Challenge 2020. The method is based on modified ResNet type convolutional neural network and is capable to automatically recognize 24 cardiac abnormalities using 12-lead ECG. We have adopted several preprocessing and learning techniques including custom tailored loss function, dedicated classification layer and Bayesian threshold optimization which have major positive impact on the model performance. At the official phase of the Challenge, our team - BUTTeam - reached a challenge validation score of 0.696, and the full test score of 0.202, placing us 21 out of 40 in the official ranking. This implies that our method performed well on data from the same source (reached first place with validation score), however, it has very poor generalization to data from different sources.","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":"122649716","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}
{"title":"Selected Features for Classification of 12-lead ECGs","authors":"M. Żyliński, G. Cybulski","doi":"10.22489/CinC.2020.061","DOIUrl":"https://doi.org/10.22489/CinC.2020.061","url":null,"abstract":"In this paper we describe our algorithm develop by the Alba_W.O. team at The PhysioNet/Computing in Cardiology Challenge 2020. Our approach achieved a challenge validation score of 0.308 and a full test score of 0.102, placing us 31 out of 40 in the official ranking. Our final algorithm is based on bootstrap-aggregated (bagged) decision trees. For the classification task, we provide a set of features extracted from 12-lead ECG, in detail describe later. We use the method implemented in PhysioNet-Cardiovascular-Signal-Toolbox: Global Electrical Heterogeneity, arterial fibrillation features, and PVC detection. We also estimate ECG periods (PR, QS, QR, PT, TP) and morphology parameters (ST elevation, QRS area, ECG value at R points). We also examine the importance of each predictor individually, for the classification task, using a t-test. All groups of used parameters, without sex shown utility in some class classification cases.","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":"127730756","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}
G. Luongo, L. Azzolin, M. Rivolta, T. Almeida, J. P. Martínez, D. Soriano, O. Dössel, R. Sassi, P. Laguna, A. Loewe
{"title":"Machine Learning to Find Areas of Rotors Sustaining Atrial Fibrillation From the ECG","authors":"G. Luongo, L. Azzolin, M. Rivolta, T. Almeida, J. P. Martínez, D. Soriano, O. Dössel, R. Sassi, P. Laguna, A. Loewe","doi":"10.22489/CinC.2020.181","DOIUrl":"https://doi.org/10.22489/CinC.2020.181","url":null,"abstract":"Atrial fibrillation (AF) is the most frequent irregular heart rhythm due to disorganized atrial electrical activity, often sustained by rotational drivers called rotors. The non-invasive localization of AF drivers can lead to improved personalized ablation strategy, suggesting pulmonary vein (PV) isolation or more complex extra-PV ablation procedures in case the driver is on other atrial regions. We used a Machine Learning approach to characterize and discriminate simulated single stable rotors (1R) location: PVs, left atrium (LA) excluding the PVs, and right atrium (RA), utilizing solely non-invasive signals (i.e., the 12-lead ECG). 1R episodes sustaining AF were simulated. 128 features were extracted from the signals. Greedy forward algorithm was implemented to select the best feature set which was fed to a decision tree classifier with hold-out cross-validation technique. All tested features showed significant discriminatory power, especially those based on recurrence quantification analysis (up to 80.9% accuracy with single feature classification). The decision tree classifier achieved 89.4% test accuracy with 18 features on simulated data, with sensitivities of 93.0%, 82.4%, and 83.3% for RA, LA, and PV classes, respectively. Our results show that a machine learning approach can potentially identify the location of 1R sustaining AF using the 12-lead ECG.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"79 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":"134016664","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}
Najmeh Fayyazifar, Selam T. Ahderom, D. Suter, A. Maiorana, G. Dwivedi
{"title":"Impact of Neural Architecture Design on Cardiac Abnormality Classification Using 12-lead ECG Signals","authors":"Najmeh Fayyazifar, Selam T. Ahderom, D. Suter, A. Maiorana, G. Dwivedi","doi":"10.22489/CinC.2020.161","DOIUrl":"https://doi.org/10.22489/CinC.2020.161","url":null,"abstract":"Cardiac rhythm abnormality, as associated with irregular heart activity, presents as changes in an electrocardiogram (ECG). In this paper, as part of the PhysioNet Challenge 2020, we propose two cardiac abnormality detection and classification neural models, using 12-lead ECG signals. Our ECU team proposes a hand-designed Recurrent Convolutional Neural Network (RCNN), consisting of 49 one-dimensional convolutional layers, 16 skip connections, and one Bi-Directional LSTM layer. This model, without relying on any pre-processing or manual feature engineering, achieved a Challenge validation score of 62.3% and a full test score of 38.2%, ranking us 9th out of 41 teams in the official ranking. Our second neural model, designed through neural architecture search, did not score on the full test dataset nor on the validation dataset; however, we optimistically expect performance improvement compared to our hand-designed RCNN model. This model scored 64.4% using 10-fold cross-validation on the training dataset, which is 2.5% higher than the training score of our RCNN model, using 10-fold cross-validation.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"172 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":"132191985","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. Palacios, I. Cygankiewicz, A. Luna, J. P. Martínez, E. Pueyo
{"title":"Sudden Cardiac Death Prediction in Chronic Heart Failure Patients by Periodic Repolarization Dynamics","authors":"S. Palacios, I. Cygankiewicz, A. Luna, J. P. Martínez, E. Pueyo","doi":"10.22489/CinC.2020.209","DOIUrl":"https://doi.org/10.22489/CinC.2020.209","url":null,"abstract":"Chronic heart failure (CHF) is a clinical syndrome associated with high mortality due to pump failure death (PFD) resulting from heart failure progression as well as to ventricular arrhythmias leading to sudden cardiac death (SCD). CHF involves autonomic nervous system imbalance, which is expected to be reflected in the electrocardiogram (ECG). Periodic Repolarization Dynamics (PRD) quantifies low-frequency oscillations in the T wave of the ECG and has been related to sympathetic modulation of ventricular repolarization. We assessed the capacity of PRD to predict PFD and SCD in a CHF population. 3-lead ECG recordings of 569 patients with symptomatic CHF were analyzed. PRD values were measured by analyzing 5-minute segments with 4-minute overlap. The minimum PRD value over the analyzed segments was assigned to each patient. PRD was higher in SCD victims than in PFD victims and than in survivors and non-cardiac death victims, although differences were not statistically significant. Low- and high-risk groups were defined by dichotomization according to median PRD in the population. Hazard ratio [95% Confidence Interval] for SCD from univariate Cox regression was 1.808 [1.031-3.169] deg (p=0.039). In conclusion, high PRD predicts SCD in a CHF population, with SCD victims presenting enhanced sympathetic-induced oscillations of ventricular repolarization.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"32 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":"134329399","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}
D. Nairn, Daniel Hunyar, Jorge Sánchez, O. Dössel, A. Loewe
{"title":"Impact of Electrode Size on Electrogram Voltage in Healthy and Diseased Tissue","authors":"D. Nairn, Daniel Hunyar, Jorge Sánchez, O. Dössel, A. Loewe","doi":"10.22489/CinC.2020.146","DOIUrl":"https://doi.org/10.22489/CinC.2020.146","url":null,"abstract":"Atrial fibrillation can be treated using low voltage (LV) (amplitude of intracardiac electrogram < 0.5mV) targeted ablation. However, catheter characteristics can alter the voltage leading to changes in identified LV areas. This study evaluates the impact electrode size has on the voltage in healthy and diseased tissue. A realistic setup was generated of tissue, bath and two high conductivity electrodes, with centre to centre spacing of 2mm, placed in contact to the tissue and perpendicular to the planar wavefront. Simulations were performed varying the dimensions of the cubic electrodes from 0.2 to 1.6 mm in healthy tissue and including fibrosis in different locations. An inverse relationship was found between the electrode size and the voltage. When including epicardial fibrosis, a voltage decrease of 1 mV was found in electrodes. When fibrosis was placed closer to the electrodes, a morphological signal change was seen and a 9 mV drop in voltage for small electrodes. Large electrodes deliver smaller voltages. A fibrotic area on the epicardial side has a small influence on the voltage, which was not amplified by increasing electrode size. Endocardial fibrosis delivers significantly smaller voltages than healthy tissue. Little difference in the voltage was seen between large electrodes (> 1 mm) in diseased tissue. Electrode size needs to be accounted for when determining LV areas using different catheters.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"599 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":"133374647","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}
M. Sallem, Amina Ghrissi, Adnen Saadaoui, V. Zarzoso
{"title":"Detection of Cardiac Arrhythmias From Varied Length Multichannel Electrocardiogram Recordings Using Deep Convolutional Neural Networks","authors":"M. Sallem, Amina Ghrissi, Adnen Saadaoui, V. Zarzoso","doi":"10.22489/CinC.2020.339","DOIUrl":"https://doi.org/10.22489/CinC.2020.339","url":null,"abstract":"Automatic identification of different arrhythmias helps cardiologists better diagnose patients with cardiovascular diseases. Deep learning algorithms are used for the classification of multichannel ECG signals into different heart rhythms. The study dataset includes a cohort of 43101 12- lead ECG recordings with various lengths. Two options are tested to standardize the recordings length: zero padding and signal repetition. Downsampling the recordings to 100 Hz allow handling the problem of different sampling frequencies of data coming from different sources. We design a deep one-dimensional convolutional neural network (CNN) called VGG-ECG, a 13-layer fully CNN for multilabel classification. Our team is called MIndS and our approach achieved a challenge validation score of 0.368, and full test score of -0.128, placing us 38 out of 41 in the official ranking.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"18 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":"115654749","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}
{"title":"Evaluation of Severity of Cardiac Ischemia Using In Silico ECG Computed From 2D Reaction Diffusion Model","authors":"S. Loeffler, J. Starobin","doi":"10.22489/CinC.2020.033","DOIUrl":"https://doi.org/10.22489/CinC.2020.033","url":null,"abstract":"This study focuses on the analysis of the bioelectrical activity of the left ventricle using a 2D Bueno-Orovio-Fenton-Cherry monodomain reaction diffusion model. ECGs signals are simulated for normal and ischemic conditions of varying severity. Changes in ischemia are examined in a single precordial lead as the size of the ischemic area increases in various locations. Analyzing this single lead ECG, we determine the ratio between ST deviation and T-wave amplitude and establish a threshold sufficient for monitoring acute ischemic event. This method may be potentially implemented to predict sudden cardiac death.","PeriodicalId":407282,"journal":{"name":"2020 Computing in Cardiology","volume":"7 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":"114200587","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}