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https://www.readbyqxmd.com/read/28874683/inter-patient-ecg-heartbeat-classification-with-temporal-vcg-optimized-by-pso
#1
Gabriel Garcia, Gladston Moreira, David Menotti, Eduardo Luz
Classifying arrhythmias can be a tough task for a human being and automating this task is highly desirable. Nevertheless fully automatic arrhythmia classification through Electrocardiogram (ECG) signals is a challenging task when the inter-patient paradigm is considered. For the inter-patient paradigm, classifiers are evaluated on signals of unknown subjects, resembling the real world scenario. In this work, we explore a novel ECG representation based on vectorcardiogram (VCG), called temporal vectorcardiogram (TVCG), along with a complex network for feature extraction...
September 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28863167/the-development-and-validation-of-an-easy-to-use-automatic-qt-interval-algorithm
#2
Ben J M Hermans, Arja S Vink, Frank C Bennis, Luc H Filippini, Veronique M F Meijborg, Arthur A M Wilde, Laurent Pison, Pieter G Postema, Tammo Delhaas
BACKGROUND: To evaluate QT-interval dynamics in patients and in drug safety analysis, beat-to-beat QT-interval measurements are increasingly used. However, interobserver differences, aberrant T-wave morphologies and changes in heart axis might hamper accurate QT-interval measurements. OBJECTIVE: To develop and validate a QT-interval algorithm robust to heart axis orientation and T-wave morphology that can be applied on a beat-to-beat basis. METHODS: Additionally to standard ECG leads, the root mean square (ECGRMS), standard deviation and vectorcardiogram were used...
2017: PloS One
https://www.readbyqxmd.com/read/28689986/quaternion-based-study-of-angular-velocity-of-the-cardiac-vector-during-myocardial-ischaemia
#3
Pablo Daniel Cruces, Pedro David Arini
BACKGROUND: Early detection of acute ischaemia through non-invasive methods remains a challenge in health research. Ischaemic condition caused by a decrease in the blood supply in a cardiac region induces hypoxia and metabolic abnormalities that contribute to the electrical instability of the heart and to the development of slow conduction in damaged tissue. METHODS: Herein, a percutaneous transluminal coronary angiography (PTCA) is considered as a model of supply ischaemia...
December 1, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28467647/prediction-of-optimal-cardiac-resynchronization-by-vectors-extracted-from-electrograms-in-dyssynchronous-canine-hearts
#4
Elien B Engels, Marc Strik, Lars B van Middendorp, Marion Kuiper, Kevin Vernooy, Frits W Prinzen
INTRODUCTION: Proper optimization of atrioventricular (AV) and interventricular (VV) intervals can improve the response to cardiac resynchronization therapy (CRT). It has been demonstrated that the area of the QRS complex (QRSarea) extracted from the vectorcardiogram can be used as a predictor of optimal CRT-device settings. We explored the possibility of extracting vectors from the electrograms (EGMs) obtained from pacing electrodes and of using these EGM-based vectors (EGMVs) to individually optimize acute hemodynamic CRT response...
May 3, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28366419/an-evaluation-of-planarity-of-the-spatial-qrs-loop-by-three-dimensional-vectorcardiography-its-emergence-and-loss
#5
Dipanjan Ray, Sandipan Hazra, Damodar Prasad Goswami, Peter W Macfarlane, Arnab Sengupta
AIMS: To objectively characterize and mathematically justify the observation that vectorcardiographic QRS loops in normal individuals are more planar than those from patients with ST elevation myocardial infarction (STEMI). METHODS: Vectorcardiograms (VCGs) were constructed from three simultaneously recorded quasi-orthogonal leads, I, aVF and V2 (sampled at 1000 samples/s). The planarity of these QRS loops was determined by fitting a surface to each loop. Goodness of fit was expressed in numerical terms...
March 22, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28347481/ventricular-repolarization-duration-and-dispersion-adaptation-after-atropine-induced-rapid-heart-rate-increase-in-healthy-adults
#6
Lennart Bergfeldt, Gunilla Lundahl, Gabriel Bergqvist, Farzad Vahedi, Lennart Gransberg
BACKGROUND: Proper adaptation of ventricular repolarization (VR) to rapid heart rate (HR) increase is crucial for cardiac electro-mechanical function. The pattern and temporal aspects of this adaptation and its components (duration and dispersion) during normal conduction are, however, incompletely known in humans and were the topic of this study. METHODS & RESULTS: The VR duration (QT & QTpeak) and dispersion (Tamplitude, Tarea & ventricular gradient; VG) responses were studied by continuous vectorcardiogram after a bolus injection of atropine 0...
July 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28111363/diffuse-myocardial-fibrosis-reduces-electrocardiographic-voltage-measures-of-left-ventricular-hypertrophy-independent-of-left-ventricular-mass
#7
Maren Maanja, Björn Wieslander, Todd T Schlegel, Ljuba Bacharova, Hussein Abu Daya, Yaron Fridman, Timothy C Wong, Erik B Schelbert, Martin Ugander
BACKGROUND: Myocardial fibrosis quantified by myocardial extracellular volume fraction (ECV) and left ventricular mass (LVM) index (LVMI) measured by cardiovascular magnetic resonance might represent independent and opposing contributors to ECG voltage measures of left ventricular hypertrophy (LVH). Diffuse myocardial fibrosis can occur in LVH and interfere with ECG voltage measures. This phenomenon could explain the decreased sensitivity of LVH detectable by ECG, a fundamental diagnostic tool in cardiology...
January 22, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28069275/optimal-configuration-of-adhesive-ecg-patches-suitable-for-long-term-monitoring-of-a-vectorcardiogram
#8
Muammar M Kabir, Erick A Perez-Alday, Jason Thomas, Golriz Sedaghat, Larisa G Tereshchenko
The purpose of this study was to develop optimal configuration of adhesive ECG patches placement on the torso, which would provide the best agreement with the Frank orthogonal ECGs. Ten seconds of orthogonal ECG followed by 3-5min of ECGs using patches at 5 different locations simultaneously on the torso were recorded in 50 participants at rest in sitting position. Median beat was generated for each ECG and 3 patch ECGs that best correlate with orthogonal ECGs were selected for each participant. For agreement analysis, spatial QRS-T angle, spatial QRS and T vector characteristics, spatial ventricular gradient, roundness, thickness and planarity of vectorcardiographic (VCG) loops were measured...
May 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28011837/non-invasive-model-based-measures-of-ventricular-electrical-dyssynchrony-for-predicting-crt-outcomes
#9
Christopher T Villongco, David E Krummen, Jeffrey H Omens, Andrew D McCulloch
AIMS: Left ventricular activation delay due to left bundle branch block (LBBB) is an important determinant of the severity of dyssynchronous heart failure (DHF). We investigated whether patient-specific computational models constructed from non-invasive measurements can provide measures of baseline dyssynchrony and its reduction after CRT that may explain the degree of long-term reverse ventricular remodelling. METHODS AND RESULTS: LV end-systolic volume reduction (ΔESVLV) measured by 2D trans-thoracic echocardiography in eight patients following 6 months of CRT was significantly (P < 0...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28011830/electrical-remodelling-in-patients-with-iatrogenic-left-bundle-branch-block
#10
MULTICENTER STUDY
Elien B Engels, Thomas T Poels, Patrick Houthuizen, Peter P T de Jaegere, Jos G Maessen, Kevin Vernooy, Frits W Prinzen
AIMS: Left bundle branch block (LBBB) is induced in approximately one-third of all transcatheter aortic valve implantation (TAVI) procedures. We investigated electrophysiological remodelling in patients with TAVI-induced LBBB. METHODS AND RESULTS: This retrospective study comprises 107 patients with initially narrow QRS complex of whom 40 did not and 67 did develop persistent LBBB after TAVI. 12-lead electrocardiograms (ECGs) taken before TAVI, within 24 hours ('acute'), and 1-12 months after TAVI ('chronic') were used to reconstruct vectorcardiograms...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28011828/changes-in-p-wave-morphology-after-pulmonary-vein-isolation-insights-from-computer-simulations
#11
Mirabeau Saha, Giulio Conte, Maria Luce Caputo, François Regoli, Rolf Krause, Angelo Auricchio, Vincent Jacquemet
AIMS: Apparently conflicting clinical measurements of P-wave duration (PWD) pre- vs. post-ablation have been reported. To assist the interpretation of these clinical data, we used a computer model of the atria and torso to simulate P waves before and after pulmonary vein (PV) isolation. METHODS AND RESULTS: Twenty ablation patterns were designed (segmental or ipsilateral ablation; five distances to PV sleeves; addition of a roof line or not). Possible PV reconnections were introduced as gaps in the ablation lines...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27742061/detection-of-elevated-pulmonary-pressures-by-the-ecg-derived-ventricular-gradient-a-comparison-of-conversion-matrices-in-patients-with-suspected-pulmonary-hypertension
#12
Marlieke L A Haeck, Gijsbert F L Kapel, Roderick W C Scherptong, Cees A Swenne, Arie C Maan, Jeroen J Bax, Martin J Schalij, Hubert W Vliegen
BACKGROUND: The aim was to assess the diagnostic value of the Inverse Dower (INVD)-derived vectorcardiogram (VCG) and the Kors-derived VCG to detect elevated systolic pulmonary artery pressure (SPAP) in suspected pulmonary hypertension (PH). METHODS: In 132 patients, morphologic variables were evaluated by comparing the VCG parameters synthesized by INVD and Kors matrix. Comparison of the diagnostic accuracy of detecting SPAP ≥50mmHg between the matrices was performed by ROC curve analysis and logistic regression analysis...
January 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/27723506/self-organizing-visualization-and-pattern-matching-of-vectorcardiographic-qrs-waveforms
#13
Hui Yang, Fabio Leonelli
QRS morphology is commonly used in the electrocardiographic diagnosis of ventricular depolarization such as left bundle branch block (LBBB) and ventricular septal infarction. We investigated whether pattern matching of QRS loops in the 3-dimensional vectorcardiogram (VCG) will improve the grouping of patients whose space-time electrical activity akin to each other, thereby assisting in clinical decision making. First, pattern dissimilarity of VCG QRS loops is qualitatively measured and characterized among patients, resulting in a 93×93 distance matrix of patient-to-patient dissimilarity...
December 1, 2016: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/27230674/why-qrs-duration-should-be-replaced-by-better-measures-of-electrical-activation-to-improve-patient-selection-for-cardiac-resynchronization-therapy
#14
REVIEW
Elien B Engels, Masih Mafi-Rad, Antonius M W van Stipdonk, Kevin Vernooy, Frits W Prinzen
Cardiac resynchronization therapy (CRT) is a well-known treatment modality for patients with a reduced left ventricular ejection fraction accompanied by a ventricular conduction delay. However, a large proportion of patients does not benefit from this therapy. Better patient selection may importantly reduce the number of non-responders. Here, we review the strengths and weaknesses of the electrocardiogram (ECG) markers currently being used in guidelines for patient selection, e.g., QRS duration and morphology...
August 2016: Journal of Cardiovascular Translational Research
https://www.readbyqxmd.com/read/27133525/controversial-and-similar-aspects-of-the-brugada-and-j-wave-patterns-the-vectorcardiogram-point-of-view-revision-2
#15
Carlos Alberto Pastore, Nelson Samesima, Horácio G Pereira Filho, Bruna A Madaloso
BACKGROUND: The J-wave electrocardiographic patterns include early repolarization (ER) and Brugada syndrome; especially when ER is located in the anteroseptal leads (V1-V3), it can mimic the Brugada syndrome (BrS) ECG pattern and therefore mislead the diagnosis. We aimed to define the vectorcardiographic characteristics of BrS and ER using aspects of QRS complex loop, J-point and ST-segment. METHODS/RESULTS: Vectorcardiographic loops in the transverse plane (TP) of 14 BrS patients and 26 individuals with ER were analyzed and defined, and then a third group of 17 patients with non-characteristic ECG patterns were analyzed and compared with them...
May 2016: Journal of Electrocardiology
https://www.readbyqxmd.com/read/26952516/subtraction-electrocardiography-detection-of-ischemia-induced-st-displacement-without-the-need-to-identify-the-j-point
#16
C Cato Ter Haar, Sum-Che Man, Arie C Maan, Martin J Schalij, Cees A Swenne
BACKGROUND: When triaging a patient with acute chest pain at first medical contact, an electrocardiogram (ECG) is routinely made and inspected for signs of myocardial ischemia. The guidelines recommend comparison of the acute and an earlier-made ECG, when available. No concrete recommendations for this comparison exist, neither is known how to handle J-point identification difficulties. Here we present a J-point independent method for such a comparison. METHODS: After conversion to vectorcardiograms, baseline and acute ischemic ECGs after 3minutes of balloon occlusion during elective PCI were compared in 81 patients of the STAFF III ECG database...
May 2016: Journal of Electrocardiology
https://www.readbyqxmd.com/read/26820616/effects-of-preexcitation-syndrome-on-terminal-qrs-vector-observed-in-spatial-vector
#17
Qingru Wang, Yang Chen, Renguang Liu, Qinghua Chang
BACKGROUND: Preexcitation syndrome could affect terminal QRS vector, which is not emphasized in clinic. In this study, we made a comparison between vectorcardiogram (VCG) before and after ablation to observe the change of terminal QRS vector. Furthermore, the relationship between the change of terminal QRS vector and accessory pathway (AP) as well as the change of initial QRS vector (delta vector) was analyzed. METHODS: Thirty patients who were proved to have a single AP by ablation were included...
November 2016: Annals of Noninvasive Electrocardiology
https://www.readbyqxmd.com/read/26806119/frank-vectorcardiographic-system-from-standard-12-lead-ecg-an-effort-to-enhance-cardiovascular-diagnosis
#18
Sidharth Maheshwari, Amit Acharyya, Michele Schiariti, Paolo Emilio Puddu
BACKGROUND: Vectorcardiogram (VCG) has been repeatedly found useful for clinical investigations. It may not substitute but complement Standard 12-Lead (S12) ECG. There was tremendous research between 1950s to mid-1980s on VCG in general and Frank's System in particular, however, in last three decades it has been dropped as a routine cardiac test, the major reasons being unconventional electrode placements which required training of the physicians, greater number of electrodes involved when used to supplement S12 system and additional hardware complexity involved, at least in the early days...
March 2016: Journal of Electrocardiology
https://www.readbyqxmd.com/read/26737464/automatic-cardiac-arrhythmia-detection-and-classification-using-vectorcardiograms-and-complex-networks
#19
Vinícius Queiroz, Eduardo Luz, Gladston Moreira, Álvaro Guarda, David Menotti
This paper intends to bring new insights in the methods for extracting features for cardiac arrhythmia detection and classification systems. We explore the possibility for utilizing vectorcardiograms (VCG) along with electrocardiograms (ECG) to get relevant informations from the heartbeats on the MIT-BIH database. For this purpose, we apply complex networks to extract features from the VCG. We follow the ANSI/AAMI EC57:1998 standard, for classifying the beats into 5 classes (N, V, S, F and Q), and de Chazal's scheme for dataset division into training and test set, with 22 folds validation setup for each set...
2015: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/26737293/performance-of-dower-s-inverse-transform-and-frank-lead-system-for-identification-of-myocardial-infarction
#20
A Aranda, P Bonizzi, J Karel, R Peeters
This study performs a comparison between Dower's inverse transform and Frank lead system for Myocardial Infarction (MI) identification. We have selected a set of relevant features for MI detection from the vectorcardiogram and used the lasso method after that to build a model for the Dower's inverse transform and one for the Frank leads system. Then we analyzed the performance between both models on MI detection. The proposed methods have been tested using PhysioNet PTB database that contains 550 records from which 368 are MIs...
August 2015: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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