Download or read book Dominant Frequency Estimation for Atrial Fibrillation Studies written by Anita Ahmad MEng and published by . This book was released on 2011 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dominant Frequency Estimation for Atrial Fibrillation Studies written by Anita Ahmad and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work explores the feasibility of using frequency domain analysis in the study of arrhythmias. The research involves the application of spectrum analysis to obtain the dominant frequency (DF) of atrial electrograms (AE) at different sites in the atria. It is an alternative way of interpreting the chaotic electrical activity seen during AF and reveals critical sites to guide ablation. As longer ablation procedure time implies higher risk to the patient, DF estimation needs to be obtained as quickly as possible. Four techniques (FFT, Blackman-Tukey, Autoregressive and Multiple Signal Classification) were used to compare the computation times taken for spectrum estimation analysis. The FFT technique produces an accurate DF result with the shortest time. DF analysis was first used for ventricular fibrillation with data from the surface of the left ventricle (in animal studies). It was found that spectrograms show the DF drifting along time and with significant changes in power. This approach was then applied for bipolar AF signals (in human studies). The changes of the frequency along time were observed when the stimulation was given, either using high frequency stimulation or drug infusion. We have developed a novel technique for the removal of ventricular signals from virtual AE. The surface ECG is used to identify ventricular activity. A band pass filter (8 Hz to 20 Hz) followed by rectification and then a low pass filter (6 Hz) are used for QRS detection. QRST subtraction was performed using three different approaches: flat, linear and spline interpolation. QRST subtraction affects the power of the signals but not the DF. We also developed an adaptive power threshold tool to observe the distribution of the DFs with an adjustable power threshold setting. Using this tool the 3D maps can display the evolution of the DFs within a chosen threshold power bracket.
Download or read book Understanding Atrial Fibrillation written by Luca Mainardi and published by Springer Nature. This book was released on 2022-05-31 with total page 109 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book presents recent advances in signal processing techniques for modeling, analysis, and understanding of the heart's electrical activity during atrial fibrillation. This arrhythmia is the most commonly encountered in clinical practice and its complex and metamorphic nature represents a challenging problem for clinicians, engineers, and scientists. Research on atrial fibrillation has stimulated the development of a wide range of signal processing tools to better understand the mechanisms ruling its initiation, maintenance, and termination. This book provides undergraduate and graduate students, as well as researchers and practicing engineers, with an overview of techniques, including time domain techniques for atrial wave extraction, time-frequency analysis for exploring wave dynamics, and nonlinear techniques to characterize the ventricular response and the organization of atrial activity. The book includes an introductory chapter about atrial fibrillation and its mechanisms, treatment, and management. The successive chapters are dedicated to the analysis of atrial signals recorded on the body surface and to the quantification of ventricular response. The rest of the book explores techniques to characterize endo- and epicardial recordings and to model atrial conduction. Under the appearance of being a monothematic book on atrial fibrillation, the reader will not only recognize common problems of biomedical signal processing but also discover that analysis of atrial fibrillation is a unique challenge for developing and testing novel signal processing tools. Table of Contents: Part I / Introduction to Atrial Fibrillation: From Mechanisms to Treatment / Time Domain Analysis of Atrial Fibrillation / Atrial Activity Extraction from the ECG / Time-Frequency Analysis of Atrial Fibrillation
Download or read book Deriving the Time course of the Dominant Frequency of Atrial Fibrillation from a Long Term in Vivo Sheep Model Using QRST Removal Techniques written by Nicholas F. Price and published by . This book was released on 2011 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis document introduces an approach taken to the study of atrial fibrillation (AF) - which is a serious and common heart disorder - using sheep as an in-vivo - inside of the animal - model. The hypothesis that the dominant frequency (DF) of AF increases gradually resulting in self-sustained AF with a persistent left-to-right atrium (LA, RA) DF difference was tested. Induction of AF was achieved using fast atrial pacing (N=8). In-vivo traces were obtained from a lead in the RA and an implantable loop recorder (ILR) in proximity to the LA. Electrocardiogram (ECG) traces were collected from weekly interrogations during 9 to 24 weeks of tachypaced - fast pacing - induced AF, which needed to be processed first by image processing algorithms to transform the traces into a form in which they could be operated on by signal analysis algorithms and then by QRST cancellation algorithms - algorithms designed to remove ventricular activity (VA) - before the fast Fourier transform was applied to obtain the DF values. To evaluate the effectiveness and compare and characterize the strengths and weaknesses of different QRST cancellation algorithms, a series of tests were performed on synthesized ECG traces. The results of these tests demonstrated that a technique based on principal component analysis was the most effective. Using this technique, it was shown that when the first AF episode was detected, the DF increased over a 2-week period (7±0.21 to 9.92±0.31 Hz. N=6, p
Download or read book Measurement of the Dominant Frequency in Atrial Fibrillation Electrograms written by C. Le Goazigo and published by . This book was released on 2005 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Pathophysiology of High frequency Dominant Frequencies in Human Atrial Fibrillation written by Armand Rostamian and published by . This book was released on 2011 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Objective : To define the physiology contributing to spectral dominant frequency (DF) in human atrial fibrillation (AF). Background : High spectral DF identifies rapid sources of AF in animal models, but ablation at such sites in humans has had limited success. Notably, minimum refractory periods (ERP) during AF, which set the maximum permissible rate ('plausible' DF), have never been defined in humans, while electrogram fractionation may introduce technical errors. We set out to determine if bi-atrial sites of high DF in both atria during human AF accurately represent rapid sources relative to manually verified rate, ERP in AF and electrogram fractionation. Methods : In AF patients (13 paroxysmal) we measured ERP in AF as the shortest atrial monophasic action potential duration (APD), and shortest F-F interval. We recorded AF simultaneously from 64-pole basket catheters in left as well as right (n=14 patients) atria, and from coronary sinus and pulmonary veins. We determined the relationship of AF CL to local ERP at each site. Results : Shortest atrial APD in AF (116±18 ms) was accurately represented by shortest local F-F interval (p0.001), giving maximum AF rate, Fmax=8.8 Hz. Spectral DF at all 1761 sites was 5.5±1.5 Hz (AF CL 194±53 ms). CL error was reduced where DF
Download or read book Bioelectrical Signal Processing in Cardiac and Neurological Applications written by Leif Sörnmo and published by Academic Press. This book was released on 2005-06-15 with total page 690 pages. Available in PDF, EPUB and Kindle. Book excerpt: The analysis of bioelectrical signals continues to receive wide attention in research as well as commercially because novel signal processing techniques have helped to uncover valuable information for improved diagnosis and therapy. This book takes a unique problem-driven approach to biomedical signal processing by considering a wide range of problems in cardiac and neurological applications-the two "heavyweight" areas of biomedical signal processing. The interdisciplinary nature of the topic is reflected in how the text interweaves physiological issues with related methodological considerations. Bioelectrical Signal Processing is suitable for a final year undergraduate or graduate course as well as for use as an authoritative reference for practicing engineers, physicians, and researchers. A problem-driven, interdisciplinary presentation of biomedical signal processing Focus on methods for processing of bioelectrical signals (ECG, EEG, evoked potentials, EMG) Covers both classical and recent signal processing techniques Emphasis on model-based statistical signal processing Comprehensive exercises and illustrations Extensive bibliography
Download or read book Electrocardiographic Imaging written by Maria S. Guillem and published by Frontiers Media SA. This book was released on 2020-04-17 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrical activity in the myocardium coordinates the contraction of the heart, and its knowledge could lead to a better understanding, diagnosis, and treatment of cardiac diseases. This electrical activity generates an electromagnetic field that propagates outside the heart and reaches the human torso surface, where it can be easily measured. Classical electrocardiography aims to interpret the 12-lead electrocardiogram (ECG) to determine cardiac activity and support the diagnosis of cardiac pathologies such as arrhythmias, altered activations, and ischemia. More recently, a higher number of leads is used to reconstruct a more detailed quantitative description of the electrical activity in the heart by solving the so-called inverse problem of electrocardiography. This technique is known as ECG imaging. Today, clinical applications of ECG imaging are showing promising results in guiding a variety of electrophysiological interventions such as catheter ablation of atrial fibrillation and ventricular tachycardia. However, in order to promote the adoption of ECG imaging in the routine clinical practice, further research is required regarding more accurate mathematical methods, further scientific validation under different preclinical scenarios and a more extensive clinical validation
Download or read book Atrial Fibrillation Technology for Diagnosis Monitoring and Treatment written by Jose F. Rodriguez Matas and published by Frontiers Media SA. This book was released on 2022-03-15 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heart Rate Variability HRV Signal Analysis written by Markad V. Kamath and published by CRC Press. This book was released on 2016-04-19 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open a Window into the Autonomic Nervous SystemQuantifying the amount of autonomic nervous system activity in an individual patient can be extremely important, because it provides a gauge of disease severity in a large number of diseases. Heart rate variability (HRV) calculated from both short-term and longer-term electrocardiograms is an ideal win
Download or read book Cardiac Electrophysiology From Cell to Bedside E Book written by Douglas P. Zipes and published by Elsevier Health Sciences. This book was released on 2017-05-13 with total page 1429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid advancements in cardiac electrophysiology require today’s health care scientists and practitioners to stay up to date with new information both at the bench and at the bedside. The fully revised 7th Edition of Cardiac Electrophysiology: From Cell to Bedside, by Drs. Douglas Zipes, Jose Jalife, and William Stevenson, provides the comprehensive, multidisciplinary coverage you need, including the underlying basic science and the latest clinical advances in the field. An attractive full-color design features color photos, tables, flow charts, ECGs, and more. All chapters have been significantly revised and updated by global leaders in the field, including 19 new chapters covering both basic and clinical topics. New topics include advances in basic science as well as recent clinical technology, such as leadless pacemakers; catheter ablation as a new class I recommendation for atrial fibrillation after failed medical therapy; current cardiac drugs and techniques; and a new video library covering topics that range from basic mapping (for the researcher) to clinical use (implantations). Each chapter is packed with the latest information necessary for optimal basic research as well as patient care, and additional figures, tables, and videos are readily available online. New editor William G. Stevenson, highly regarded in the EP community, brings a fresh perspective to this award-winning text. Expert Consult eBook version included with purchase. This enhanced eBook experience allows you to search all of the text, figures, images, videos (including video updates), glossary, and references from the book on a variety of devices.
Download or read book Frontiers in Noninvasive Cardiac Mapping An Issue of Cardiac Electrophysiology Clinics written by Ashok Shah and published by Elsevier Health Sciences. This book was released on 2015-04-07 with total page 185 pages. Available in PDF, EPUB and Kindle. Book excerpt: This issue of Cardiac Electrophysiology Clinics examines Frontiers in Non-invasive Cardiac Mapping. Topics include imaging of heart rhythm disorders, experimental validation and modeling of validation, challenges and future directions of inverse problems, phase mapping of cardiac fibrillation, frequency domain analysis, analysis of diagnostic 12-lead electrocardiography and 3D non-invasive mapping, and many more.
Download or read book Practical Guide to Catheter Ablation of Atrial Fibrillation written by Jonathan S. Steinberg and published by John Wiley & Sons. This book was released on 2016-01-26 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Now in its second edition, this practical guide offers clear-headed guidance to the successful application of catheter ablation for atrial fibrillation. This book concentrates on clinically-relevant information that providers can put to immediate use caring for patients. Takes a clear-headed practical approach to ablation of atrial fibrillation – long on actionable, clinically-relevant guidance, succinct and to-the-point on the theory behind the procedure Edited by three leading, internationally-known electrophysiologists with extensive experience in ablation for atrial fibrillation Written by international team of experts reflecting global best practices from centers with considerable experience in the use of catheter ablation Format designed to serve the needs of electrophysiologists regardless of experience, electrophysiology fellows, electrophysiology nurses and lab technical staff Covers hot topics such as new noninvasive imaging techniques, the treatment of challenging left atrial flutters, options for persistent atrial fibrillation and when a redo ablation is needed; and novel application of ablation targeting the autonomic nervous system
Download or read book Electrical and Structural Remodelling in Atrial Fibrillation Phenotypes for Personalized Therapy written by Vijay S. Chauhan and published by Frontiers Media SA. This book was released on 2021-07-27 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Zipes and Jalife s Cardiac Electrophysiology From Cell to Bedside written by Jose Jalife and published by Elsevier Health Sciences. This book was released on 2021-12-16 with total page 1709 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fully updated from cover to cover, Zipes and Jalife’s Cardiac Electrophysiology: From Cell to Bedside, 8th Edition, provides the comprehensive, multidisciplinary coverage you need—from new knowledge in basic science to the latest clinical advances in the field. Drs. José Jalife and William Gregory Stevenson lead a team of global experts who provide cutting-edge content and step-by-step instructions for all aspects of cardiac electrophysiology. Packs each chapter with the latest information necessary for optimal basic research as well as patient care. Covers new technologies such as CRISPR, protein research, improved cardiac imaging, optical mapping, and wearable devices. Contains significant updates in the areas of molecular biology and genetics, iPSCs (induced pluripotent stem cells), embryonic stem cells, precision medicine, antiarrhythmic drug therapy, cardiac mapping with advanced techniques, and ablation technologies including stereotactic radioablation. Includes 47 new standalone chapters that are organized into discrete topics for improved access. Discusses extensive recent progress in the understanding, diagnosis, and management of arrhythmias, including new clinical insights on atrial fibrillation and stroke prevention, new advances in the understanding of ventricular arrythmias in genetic disease, and advances in implantable devises and infection management. Features 1,600 high-quality photographs, anatomic and radiographic images, electrocardiograms, tables, algorithms, and more., with additional figures, tables, and videos online. Recipient of a 2018 Highly Commended award from the British Medical Association.
Download or read book Interpreting Cardiac Electrograms written by Kevin Michael and published by BoD – Books on Demand. This book was released on 2017-10-18 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a reference book aimed at cardiologists, electrophysiologists and fellows in training. It presents an expansive review of cardiac electrogram interpretation in a collation of manuscripts that represent clinical studies, relevant anecdotal cases and basic science chapters evaluating cardiac signal processing pertaining to persistent atrial fibrillation. A diagnostic approach to arrhythmias using a standard ECG, the signal average ECG and fetal ECG is highlighted. Intracardiac ICD electrograms are also explored in terms of trouble shooting and device programming.
Download or read book Catheter Ablation of Atrial Fibrillation written by Etienne Aliot and published by John Wiley & Sons. This book was released on 2011-08-31 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catheter Ablation of Atrial Fibrillation Edited by Etienne Aliot, MD, FESC, FACC, FHRS Chief of Cardiology, Hôpital Central, University of Nancy, France Michel Haïssaguerre, MD Chief of Electrophysiology, Hôpital Cardiologique du Haut-Lévêque, France Warren M. Jackman, MD Chief of Electrophysiology, University of Oklahoma Health Science Center, USA In this text, internationally recognized authors explore and explain the advances in basic and clinical electrophysiology that have had the greatest impact on catheter ablation of atrial fibrillation (AF). Designed to assist in patient care, stimulate research projects, and continue the remarkable advances in catheter ablation of AF, the book covers: the fundamental concepts of AF, origin of signals, computer simulation, and updated reviews of ablation tools the present practical approaches to the ablation of specific targets in the fibrillating atria, including pulmonary veins, atrial neural network, fragmented electrograms, and linear lesions, as well as the strategies in paroxysmal or chronic AF or facing left atrial tachycardias the special challenge of heart failure patients, the impact of ablation on mortality, atrial mechanical function, and lessons from surgical AF ablation Richly illustrated by numerous high-quality images, Catheter Ablation of Atrial Fibrillation will help every member of the patient care team.
