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Masè M, Cristoforetti A, Del Greco M, Ravelli F. A Divergence-Based Approach for the Identification of Atrial Fibrillation Focal Drivers From Multipolar Mapping: A Computational Study. Front Physiol 2021; 12:749430. [PMID: 35002755 PMCID: PMC8740027 DOI: 10.3389/fphys.2021.749430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/30/2021] [Indexed: 11/13/2022] Open
Abstract
The expanding role of catheter ablation of atrial fibrillation (AF) has stimulated the development of novel mapping strategies to guide the procedure. We introduce a novel approach to characterize wave propagation and identify AF focal drivers from multipolar mapping data. The method reconstructs continuous activation patterns in the mapping area by a radial basis function (RBF) interpolation of multisite activation time series. Velocity vector fields are analytically determined, and the vector field divergence is used as a marker of focal drivers. The method was validated in a tissue patch cellular automaton model and in an anatomically realistic left atrial (LA) model with Courtemanche-Ramirez-Nattel ionic dynamics. Divergence analysis was effective in identifying focal drivers in a complex simulated AF pattern. Localization was reliable even with consistent reduction (47%) in the number of mapping points and in the presence of activation time misdetections (noise <10% of the cycle length). Proof-of-concept application of the method to human AF mapping data showed that divergence analysis consistently detected focal activation in the pulmonary veins and LA appendage area. These results suggest the potential of divergence analysis in combination with multipolar mapping to identify AF critical sites. Further studies on large clinical datasets may help to assess the clinical feasibility and benefit of divergence analysis for the optimization of ablation treatment.
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Affiliation(s)
- Michela Masè
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
- Institute of Mountain Emergency Medicine, EURAC Research, Bolzano, Italy
| | - Alessandro Cristoforetti
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
| | - Maurizio Del Greco
- Division of Cardiology, Santa Maria del Carmine Hospital, Rovereto, Italy
| | - Flavia Ravelli
- Laboratory of Biophysics and Translational Cardiology, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy
- CISMed – Centre for Medical Sciences, University of Trento, Trento, Italy
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Dharmaprani D, Dykes L, McGavigan AD, Kuklik P, Pope K, Ganesan AN. Information Theory and Atrial Fibrillation (AF): A Review. Front Physiol 2018; 9:957. [PMID: 30050471 PMCID: PMC6052893 DOI: 10.3389/fphys.2018.00957] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 06/29/2018] [Indexed: 11/13/2022] Open
Abstract
Atrial Fibrillation (AF) is the most common cardiac rhythm disorder seen in hospitals and in general practice, accounting for up to a third of arrhythmia related hospitalizations. Unfortunately, AF treatment is in practice complicated by the lack of understanding of the fundamental mechanisms underlying the arrhythmia, which makes detection of effective ablation targets particularly difficult. Various approaches to AF mapping have been explored in the hopes of better pinpointing these effective targets, such as Dominant Frequency (DF) analysis, complex fractionated electrograms (CFAE) and unipolar reconstruction (FIRM), but many of these methods have produced conflicting results or require further investigation. Exploration of AF using information theoretic-based approaches may have the potential to provide new insights into the complex system dynamics of AF, whilst also providing the benefit of being less reliant on empirically derived definitions in comparison to alternate mapping approaches. This work provides an overview of information theory and reviews its applications in AF analysis, with particular focus on AF mapping. The works discussed in this review demonstrate how understanding AF from a signal property perspective can provide new insights into the arrhythmic phenomena, which may have valuable clinical implications for AF mapping and ablation in the future.
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Affiliation(s)
- Dhani Dharmaprani
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia
| | - Lukah Dykes
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Andrew D. McGavigan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
| | - Pawel Kuklik
- Department of Cardiology, University Medical Centre, Hamburg, Germany
| | - Kenneth Pope
- College of Science and Engineering, Flinders University of South Australia, Adelaide, SA, Australia
| | - Anand N. Ganesan
- College of Medicine and Public Health, Flinders University of South Australia, Adelaide, SA, Australia
- Department of Cardiovascular Medicine, Flinders Medical Centre, Adelaide, SA, Australia
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Greco A, Messerotti Benvenuti S, Gentili C, Palomba D, Scilingo EP, Valenza G. Assessment of linear and nonlinear/complex heartbeat dynamics in subclinical depression (dysphoria). Physiol Meas 2018; 39:034004. [DOI: 10.1088/1361-6579/aaaeac] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Duhart JM, Brocardo L, Caldart CS, Marpegan L, Golombek DA. Circadian Alterations in a Murine Model of Hypothalamic Glioma. Front Physiol 2017; 8:864. [PMID: 29163208 PMCID: PMC5670357 DOI: 10.3389/fphys.2017.00864] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 10/16/2017] [Indexed: 01/09/2023] Open
Abstract
The mammalian circadian system is controlled by a central oscillator located in the suprachiasmatic nuclei (SCN) of the hypothalamus, in which glia appears to play a prominent role. Gliomas originate from glial cells and are the primary brain tumors with the highest incidence and mortality. Optic pathway/hypothalamic gliomas account for 4–7% of all pediatric intracranial tumors. Given the anatomical location, which compromises both the circadian pacemaker and its photic input pathway, we decided to study whether the presence of gliomas in the hypothalamic region could alter circadian behavioral outputs. Athymic nude mice implanted with LN229 human glioma cells showed an increase in the endogenous period of the circadian clock, which was also less robust in terms of sustaining the free running period throughout 2 weeks of screening. We also found that implanted mice showed a slower resynchronization rate after an abrupt 6 h advance of the light-dark (LD) cycle, advanced phase angle, and a decreased direct effect of light in general activity (masking), indicating that hypothalamic tumors could also affect photic sensitivity of the circadian clock. Our work suggests that hypothalamic gliomas have a clear impact both on the endogenous pacemaking of the circadian system, as well as on the photic synchronization of the clock. These findings strongly suggest that the observation of altered circadian parameters in patients might be of relevance for glioma diagnosis.
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Affiliation(s)
- José M Duhart
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Lucila Brocardo
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Carlos S Caldart
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Luciano Marpegan
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
| | - Diego A Golombek
- Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, Argentina
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Xin Y, Zhao Y, Mu Y, Li Q, Shi C. Paroxysmal atrial fibrillation recognition based on multi-scale Rényi entropy of ECG. Technol Health Care 2017; 25:189-196. [PMID: 28582906 DOI: 10.3233/thc-171321] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is a common type of arrhythmia disease, which has a high morbidity and can lead to some serious complications. The ability to detect and in turn prevent AF is extremely significant to the patient and clinician. OBJECTIVE Using ECG to detect AF and develop a robust and effective algorithm is the primary objective of this study. METHODS Some studies show that after AF occurs, the regulatory mechanism of vagus nerve and sympathetic nerve will change. Each R-R interval will be absolutely unequal. After studying the physiological mechanism of AF, we will calculate the Rényi entropy of the wavelet coefficients of heart rate variability (HRV) in order to measure the complexity of PAF signals, as well as extract the multi-scale features of paroxysmal atrial fibrillation (PAF). RESULTS The data used in this study is obtained from MIT-BIH PAF Prediction Challenge Database and the correct rate in classifying PAF patients from normal persons is 92.48%. CONCLUSIONS The results of this experiment proved that AF could be detected by using this method and, in turn, provide opinions for clinical diagnosis.
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Balasundaram K, Umapathy K, Jeyaratnam J, Niri A, Massé S, Farid T, Nair K, Asta J, Cusimano RJ, Vigmond E, Nanthakumar K. Tracking rotors with minimal electrodes: modulation index-based strategy. Circ Arrhythm Electrophysiol 2015; 8:447-55. [PMID: 25740825 DOI: 10.1161/circep.114.002306] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 02/03/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND High-frequency periodic sources during cardiac fibrillation can be detected by phase mapping techniques. To enable practical therapeutic options for modulating periodic sources (existing techniques require high density multielectrode arrays and real time simultaneous mapping capability), a method to identify electrogram morphologies colocalizing to rotors that can be implemented on few electrograms needs to be devised. METHOD AND RESULTS Multichannel ventricular fibrillation electrogram data from 7 isolated human hearts using Langendorff setup and intraoperative clinical data from 2 human hearts were included in the analysis. The spatial locations of rotors were identified using phase maps constructed from 112 electrograms. Electrograms were analyzed for repeating patterns and discriminating signal morphologies around the locations of rotors and nonrotors were identified and quantified. Features were extracted from the unipolar electrogram patterns, which corroborated well with the spatial location of rotors. The results suggest that using the proposed modulation index feature, and as low as 1 sample point in the vicinity of the rotors, an accuracy as high as 86% (P<0.001) was obtained in separating rotor locations versus nonrotor locations. The analysis of bipolar electrogram signatures in the vicinity of the rotor locations suggest that 62.5% of the rotors occur at locations where the bipolar electrogram demonstrates continuous activities during ventricular fibrillation. CONCLUSIONS Unipolar electrogram extracted modulation index-based detection of rotors is feasible with few electrodes and has greater detection rate than bipolar approach. This strategy may be suitable for nonarray-based single mapping catheter enabled detection of rotors.
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Affiliation(s)
- Krishnanand Balasundaram
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Karthikeyan Umapathy
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Joyce Jeyaratnam
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Ahmed Niri
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Stephane Massé
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Talha Farid
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Krishnakumar Nair
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - John Asta
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Robert J Cusimano
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Edward Vigmond
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.)
| | - Kumaraswamy Nanthakumar
- From the Department of Electrical and Computer Engineering, Ryerson University, Toronto, Ontario, Canada (K.B., K.U., J.J., A.N.); Department of Cardiology, THFCFM Laboratory, Toronto, Ontario, Canada (S.M., T.F., K.N., J.A., K.N.); Department of Cardiology, Toronto General Hospital, Toronto, Ontario, Canada (R.J.C.); and LIRYC Electrophysiology and Heart Modelling Institute, Pessac, France (E.V.); and Laboratory IMB, University of Bordeaux, Talence, France (E.V.).
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Zhang L, Yang C, Nie Z. Quantitative assessment of synchronization during atrial fibrillation based on a novel index. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2015; 2014:998-1001. [PMID: 25570129 DOI: 10.1109/embc.2014.6943761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Atrial Fibrillation (AF), a chaotic rhythm classically considered with random electrical activity, is now demonstrated to show a certain degree of organization and synchronization. Rather than those traditional indices which always focus on the pairwise properties of adjacent signals, a new synchronization index-S estimator-is introduced in this paper to quantify the synchronization level for all the signals in a selected area. By evaluating a complement of the entropy of the normalized eigenvalues of the corresponding correlation matrix, S estimator is designed to be proportional to the amount of synchronization. 400 episodes of 64-channel epicardial signals acquired from four living mongrels were studied under normal sinus rhythm (SN) and AF. The results showed that there were significant decreases of S estimator for both anterior left atrium and anterior right atrium with the rhythm changing from SN to AF. After dividing the research area into eight subparts, S estimator is also capable to demonstrate the different synchronization level for each subpart and revealed the electrophysiology individual difference among four experimental subjects. In conclusion, S estimator succeeds in estimating the synchronization degree for multi-channel signals in a selected area, with no limits to the number of the signals to be analyzed. It can help us to distinguish the region with a high synchronization level during AF, which would be helpful to the clinical AF treatment and enhance our understanding of underlying mechanisms of AF.
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Fujii S, Watanabe H, Oohashi H, Hirashima M, Nozaki D, Taga G. Precursors of dancing and singing to music in three- to four-months-old infants. PLoS One 2014; 9:e97680. [PMID: 24837135 PMCID: PMC4023986 DOI: 10.1371/journal.pone.0097680] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 04/22/2014] [Indexed: 12/01/2022] Open
Abstract
Dancing and singing to music involve auditory-motor coordination and have been essential to our human culture since ancient times. Although scholars have been trying to understand the evolutionary and developmental origin of music, early human developmental manifestations of auditory-motor interactions in music have not been fully investigated. Here we report limb movements and vocalizations in three- to four-months-old infants while they listened to music and were in silence. In the group analysis, we found no significant increase in the amount of movement or in the relative power spectrum density around the musical tempo in the music condition compared to the silent condition. Intriguingly, however, there were two infants who demonstrated striking increases in the rhythmic movements via kicking or arm-waving around the musical tempo during listening to music. Monte-Carlo statistics with phase-randomized surrogate data revealed that the limb movements of these individuals were significantly synchronized to the musical beat. Moreover, we found a clear increase in the formant variability of vocalizations in the group during music perception. These results suggest that infants at this age are already primed with their bodies to interact with music via limb movements and vocalizations.
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Affiliation(s)
- Shinya Fujii
- The Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute, Toronto, Ontario, Canada
- Research Fellow of the Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
- * E-mail:
| | - Hama Watanabe
- Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroki Oohashi
- Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
- Research Fellow of the Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
| | - Masaya Hirashima
- Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Daichi Nozaki
- Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Gentaro Taga
- Graduate School of Education, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Ravelli F, Masè M. Computational mapping in atrial fibrillation: how the integration of signal-derived maps may guide the localization of critical sources. ACTA ACUST UNITED AC 2014; 16:714-23. [DOI: 10.1093/europace/eut376] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Valenza G, Citi L, Scilingo EP, Barbieri R. Inhomogeneous point-process entropy: an instantaneous measure of complexity in discrete systems. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:052803. [PMID: 25353840 DOI: 10.1103/physreve.89.052803] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Indexed: 05/06/2023]
Abstract
Measures of entropy have been widely used to characterize complexity, particularly in physiological dynamical systems modeled in discrete time. Current approaches associate these measures to finite single values within an observation window, thus not being able to characterize the system evolution at each moment in time. Here, we propose a new definition of approximate and sample entropy based on the inhomogeneous point-process theory. The discrete time series is modeled through probability density functions, which characterize and predict the time until the next event occurs as a function of the past history. Laguerre expansions of the Wiener-Volterra autoregressive terms account for the long-term nonlinear information. As the proposed measures of entropy are instantaneously defined through probability functions, the novel indices are able to provide instantaneous tracking of the system complexity. The new measures are tested on synthetic data, as well as on real data gathered from heartbeat dynamics of healthy subjects and patients with cardiac heart failure and gait recordings from short walks of young and elderly subjects. Results show that instantaneous complexity is able to effectively track the system dynamics and is not affected by statistical noise properties.
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Affiliation(s)
- Gaetano Valenza
- Department of Anesthesia, Critical Care & Pain Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA, and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA and Research Center E. Piaggio and Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Luca Citi
- Department of Anesthesia, Critical Care & Pain Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA, and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA and School of Computer Science and Electronic Engineering, University of Essex, Colchester, United Kingdom
| | - Enzo Pasquale Scilingo
- Research Center E. Piaggio and Department of Information Engineering, University of Pisa, Pisa, Italy
| | - Riccardo Barbieri
- Department of Anesthesia, Critical Care & Pain Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts, USA, and Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Fujii S, Schlaug G. The Harvard Beat Assessment Test (H-BAT): a battery for assessing beat perception and production and their dissociation. Front Hum Neurosci 2013; 7:771. [PMID: 24324421 PMCID: PMC3840802 DOI: 10.3389/fnhum.2013.00771] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 11/02/2013] [Indexed: 11/13/2022] Open
Abstract
Humans have the abilities to perceive, produce, and synchronize with a musical beat, yet there are widespread individual differences. To investigate these abilities and to determine if a dissociation between beat perception and production exists, we developed the Harvard Beat Assessment Test (H-BAT), a new battery that assesses beat perception and production abilities. H-BAT consists of four subtests: (1) music tapping test (MTT), (2) beat saliency test (BST), (3) beat interval test (BIT), and (4) beat finding and interval test (BFIT). MTT measures the degree of tapping synchronization with the beat of music, whereas BST, BIT, and BFIT measure perception and production thresholds via psychophysical adaptive stair-case methods. We administered the H-BAT on thirty individuals and investigated the performance distribution across these individuals in each subtest. There was a wide distribution in individual abilities to tap in synchrony with the beat of music during the MTT. The degree of synchronization consistency was negatively correlated with thresholds in the BST, BIT, and BFIT: a lower degree of synchronization was associated with higher perception and production thresholds. H-BAT can be a useful tool in determining an individual's ability to perceive and produce a beat within a single session.
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Affiliation(s)
- Shinya Fujii
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School Boston, MA, USA
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12
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Nonlinear synchronization assessment between atrial and ventricular activations series from the surface ECG in atrial fibrillation. Biomed Signal Process Control 2013. [DOI: 10.1016/j.bspc.2013.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Alcaraz R, Hornero F, Rieta JJ. Dynamic time warping applied to estimate atrial fibrillation temporal organization from the surface electrocardiogram. Med Eng Phys 2013; 35:1341-8. [PMID: 23566715 DOI: 10.1016/j.medengphy.2013.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 03/01/2013] [Accepted: 03/09/2013] [Indexed: 11/30/2022]
Abstract
Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia in clinical practice. However, the mechanisms responsible for its induction and maintenance still are not fully understood. To this respect, analysis of the electrical activity organization within the atria could play an important role in their proper interpretation. Although many algorithms to quantify AF organization from invasive electrograms can be found in the literature, a reduced number of indirect estimators from the standard ECG have been proposed to date. Furthermore, these surface methods can only yield a global AF organization assessment, blurring the possible information that each individual fibrillatory (f) wave may provide. To this respect, the present manuscript proposes a novel method for direct and short-time AF organization estimation from single-lead surface ECG recordings. Through the computation of morphological variations among f waves, the temporal arrhythmia organization is estimated. The f waves are individually extracted and delineated from the atrial activity signal, making use of a dynamic time warping approach. The proposed algorithm was tested on real AF surface recordings in order to discriminate atrial signals with different organization degrees, obtaining a diagnostic accuracy higher than 88%. In addition, its performance was validated by comparison with two temporal organization measures from invasive unipolar electrograms of both atria, providing statistically significant linear correlations between invasive and non-invasive estimates. As a consequence, new standpoints are opened through this work in the non-invasive analysis of AF, where the individualized study of each f wave could assess short-time AF organization, would improve the understanding of AF mechanisms and become useful for its clinical treatment.
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Affiliation(s)
- Raúl Alcaraz
- Innovation in Bioengineering Research Group, University of Castilla-La Mancha, Spain.
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Chin-En Kuo, Sheng-Fu Liang, Shao-Sheng Lu, Tang-Ching Kuan, Chih-Sheng Lin. Estimation and Prediction of Drug Therapy on the Termination of Atrial Fibrillation by Autoregressive Model With Exogenous Inputs. IEEE J Biomed Health Inform 2013; 17:153-61. [DOI: 10.1109/titb.2012.2224877] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Alcaraz R, Hornero F, Martínez A, Rieta JJ. Short-time regularity assessment of fibrillatory waves from the surface ECG in atrial fibrillation. Physiol Meas 2012; 33:969-84. [DOI: 10.1088/0967-3334/33/6/969] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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16
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Lammers WJEP, Al-Bloushi HM, Al-Eisaei SA, Al-Dhaheri FA, Stephen B, John R, Dhanasekaran S, Karam SM. Slow wave propagation and plasticity of interstitial cells of Cajal in the small intestine of diabetic rats. Exp Physiol 2011; 96:1039-48. [PMID: 21742753 DOI: 10.1113/expphysiol.2011.058941] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The number of myenteric interstitial cells of Cajal (ICC-MY), responsible for the generation and propagation of the slow wave in the small intestine, has been shown to decrease in diabetes, suggesting impairment of slow-wave (SW) propagation and related motility. To date, however, this expected decrease in SW propagation has neither been recorded nor analysed. Eleven rats were treated with streptozotocin and housed in pairs with 11 age-matched control animals. After 3 or 7 months, segments of duodenum, jejunum and ileum were isolated and divided into two parts. One part was processed for immediate freezing, cryosectioning and immunoprobing using anti-c-Kit antibody to quantify ICC-MY. The second part was superfused in a tissue bath, and SW propagation was recorded with 121 extracellular electrodes. In addition, a cellular automaton was developed to study the effects of increasing the number of inactive cells on overall propagation. The number of ICC-MY was significantly reduced after 3 months of diabetes, but rebounded to control levels after 7 months of diabetes. Slow-wave frequencies, velocities and extracellular amplitudes were unchanged at any stage of diabetes. The cellular automaton showed that SW velocity was not linearly related to the number of inactive cells. The depletion of ICC-MY is not as severe as is often assumed and in fact may rebound after some time. In addition, at least in the streptozotocin model, the initial reduction in ICC-MY is not enough to affect SW propagation. Diabetic intestinal dysfunction may therefore be more affected by impairments of other systems, such as the enteric system or the muscle cells.
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Affiliation(s)
- Wim J E P Lammers
- Department of Physiology, Faculty of Medicine and Health Sciences, PO Box 17666, Al Ain, United Arab Emirates.
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17
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Masé M, Ravelli F. Automatic reconstruction of activation and velocity maps from electro-anatomic data by radial basis functions. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2010:2608-11. [PMID: 21096180 DOI: 10.1109/iembs.2010.5626616] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The integration of mapping techniques with suitable methods for the characterization and visualization of propagation patterns may enhance the targeting of critical arrhythmic areas, thus optimizing the ablative treatment of atrial arrhythmias. In this study, we tested the feasibility of an innovative approach for the automatic determination of activation and velocity maps from sparse data as provided by electro-anatomic mapping systems. The proposed algorithm reconstructed the activation process by a radial basis function (RBF) interpolation of mapping point latencies. Velocity vectors were analytically determined by differentiation of the interpolation function. The method was tested by a multistate cellular automaton simulation model, implemented on a CARTO-derived atrial endocardial surface, and reconstruction accuracy was evaluated as a function of the number of mapping points. The RBF algorithm accurately reconstructed wave propagation patterns in simulated tissues with homogeneous and heterogeneous conduction properties, consistently with the data access afforded by clinical practice. These preliminary results suggest the possible integration of the method with clinically-used mapping systems to favor the identification of specific propagation patterns and conduction disturbances.
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Affiliation(s)
- M Masé
- Biosignals and Biophysics Lab, Department of Physics and BIOtech, Trento, Italy.
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18
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Ravelli F, Masè M. A time-domain approach for the identification of atrial fibrillation drivers. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2011; 2011:5527-5530. [PMID: 22255590 DOI: 10.1109/iembs.2011.6091410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The localization of atrial fibrillation (AF) driver sources, characterized by rapid and regular electrical activity, is crucial for an effective ablation treatment. This work proposes a double-criteria approach for the identification of AF drivers based on a time-domain evaluation of atrial rate and AF organization. These two features are quantified by the measurement of atrial cycle length (ACL) and wave-similarity (WS). Based on ACL/WS formalism, AF drivers can be operatively defined as sites displaying electrical activity with high-rate and high-similarity (HR AND HS). The capability of ACL/WS analysis to identify AF driver sites and distinguish them from non-critical areas is shown in representative examples. The double-criteria evaluation for the identification of AF drivers, provided by our time-domain approach, might open new perspectives for the development of electrogram-guided ablation strategies in the single patient.
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Affiliation(s)
- Flavia Ravelli
- Biosignals and Biophysics Laboratory, Department of Physics and BIOtech, University of Trento, Trento, Italy.
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19
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Masè M, Graffigna A, Sinelli S, Pallaoro G, Nollo G, Ravelli F. Long-term biatrial recordings in post-operative atrial fibrillation. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2010:2654-7. [PMID: 21096191 DOI: 10.1109/iembs.2010.5626541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although atrial fibrillation (AF) is a common complication of cardiac surgery, its pathophysiology remains unclear. The study of post-operative AF demands for the recording of cardiac electrical activity in correspondence of AF onset and progression. Long-term recordings in post-surgery patients could provide this information, but, to date, have been limited to surface signals, which precludes a characterization of the arrhythmic triggers and substrate. In this study we demonstrate the feasibility of a continuous long-term recording of atrial electrical activities from the right and left atria in post-surgery patients. Local atrial epicardial electrograms are acquired by positioning temporary pacing wires in the right and left atria at the end of the intervention, while three day recordings are obtained by a digital holter recorder, adapted to epicardial signal features. The capability of the system to map local atrial activity and the possibility to obtain quantitative information on atrial rate and synchronization from the processed epicardial signals are proven in representative examples. The quantitative description of local atrial properties opens new perspective in the investigation of post-surgery AF.
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Affiliation(s)
- M Masè
- Biosignals and Biophysics Lab, Department of Physics and BIOtech, Trento, Italy.
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20
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RAVELLI FLAVIA, MASÈ MICHELA, DEL GRECO MAURIZIO, MARINI MASSIMILIANO, DISERTORI MARCELLO. Acute Atrial Dilatation Slows Conduction and Increases AF Vulnerability in the Human Atrium. J Cardiovasc Electrophysiol 2010; 22:394-401. [DOI: 10.1111/j.1540-8167.2010.01939.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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21
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Weber FM, Schilling C, Seemann G, Luik A, Schmitt C, Lorenz C, Dössel O. Wave-Direction and Conduction-Velocity Analysis From Intracardiac Electrograms–A Single-Shot Technique. IEEE Trans Biomed Eng 2010; 57:2394-401. [PMID: 20595079 DOI: 10.1109/tbme.2010.2055056] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Frank M Weber
- Institute of Biomedical Engineering, Karlsruhe Institute of Technology, Karlsruhe 76131, Germany.
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22
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Right atrial organization and wavefront analysis in atrial fibrillation. Med Biol Eng Comput 2009; 47:1237-46. [DOI: 10.1007/s11517-009-0540-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Accepted: 09/17/2009] [Indexed: 11/26/2022]
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23
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Richter U, Stridh M, Bollmann A, Husser D, Sörnmo L. Spatial characteristics of atrial fibrillation electrocardiograms. J Electrocardiol 2008; 41:165-72. [PMID: 18328340 DOI: 10.1016/j.jelectrocard.2007.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 10/29/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND The present study investigates spatial properties of atrial fibrillation (AF) by analyzing vectorcardiogram loops synthesized from 12-lead electrocardiograms (ECGs). METHODS After atrial signal extraction, spatial properties are characterized through analysis of successive, fixed-length signal segments and expressed in loop orientation, that is, azimuth and elevation, as well as in loop morphology, that is, planarity and planar geometry. It is hypothesized that more organized AF, expressed by a lower AF frequency, is associated with decreased variability in loop morphology. Atrial fibrillation frequency is determined using spectral analysis. RESULTS Twenty-six patients with chronic AF were analyzed using 60-second ECG recordings. Loop orientation was similar when determined from either entire 60- or 1-second segments. For 1-second segments, the correlation between AF frequency and the parameters planarity and planar geometry were 0.608 (P < .001) and 0.543 (P < .005), respectively. CONCLUSIONS Quantification of AF organization based on AF frequency and spatial characteristics from the ECG is possible. The results suggested a relatively weak coupling between loop morphology and AF frequency when determined from the surface ECG.
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Affiliation(s)
- Ulrike Richter
- Signal Processing Group, Department of Electrical and Information Technology, Lund University, Lund, Sweden.
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24
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Faes L, Ravelli F. A morphology-based approach to the evaluation of atrial fibrillation organization. ACTA ACUST UNITED AC 2007; 26:59-67. [PMID: 17672233 DOI: 10.1109/memb.2007.384097] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Luca Faes
- Department of Physics, University of Trento, Italy.
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25
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Rieta JJ, Hornero F. Comparative study of methods for ventricular activity cancellation in atrial electrograms of atrial fibrillation. Physiol Meas 2007; 28:925-36. [PMID: 17664683 DOI: 10.1088/0967-3334/28/8/014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Atrial fibrillation is a very common cardiovascular disease in clinical practice. One relevant issue to understand its pathophysiological mechanisms is the analysis and interpretation of atrial electrograms (AEG). To study these signals properly, ventricular activity has to be removed from the AEG. In this work, a new application of independent component analysis (ICA) to the AEG is presented, where ventricular activity is removed from atrial epicardial recordings making use of only one reference lead. Therefore the technique is suitable when multi-lead recordings are unavailable as in atrial implantable cardioverter defibrilators. In addition to the proposed new methodology this work also presents the first comparative study, making use of unipolar epicardial AEGs, among the ICA-based technique, template matching and subtraction (TMS), and adaptive ventricular cancellation (AVC) on a database of 20 patients. A performance comparative analysis was carried out by evaluating epicardial atrial waveform similarity (S) and ventricular depolarization reduction (VDR) as a function of atrial rhythm regularity on a beat-by-beat basis. Results indicate that, when the epicardial atrial rhythm is quite organized, ICA is able to preserve the atrial waveform very precisely and better than the other methods (median S = 99.64% +/- 0.31% in contrast to 95.18% +/- 2.71% for TMS and 94.76% +/- 4.12% for AVC). Moreover, ventricular reduction is the best for ICA (median VDR = 6.32 +/- 4.41 dB in contrast to 4.98 +/- 4.48 dB for TMS and 4.12 +/- 2.72 dB for AVC). On the other hand, when the atrial activity is disorganized, TMS notably improves performance (S = 97.72% +/- 1.87%), but ICA still is the best in waveform preservation (S = 98.22% +/- 1.53%) whereas AVC remains similar (S = 93.74% +/- 4.38%). In conclusion, ICA can be considered as notably the best approach to reduce ventricular activity from unipolar atrial electrograms in organized atrial arrhythmias. On the other hand, both TMS and ICA give quite similar results when the atrial arrhythmia is disorganized.
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Affiliation(s)
- José Joaquín Rieta
- Biomedical Synergy, Valencia University of Technology, Campus de Gandia, 46730, Gandia, Spain.
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26
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Corino VD, Sassi R, Mainardi LT, Cerutti S. Signal processing methods for information enhancement in atrial fibrillation: Spectral analysis and non-linear parameters. Biomed Signal Process Control 2006. [DOI: 10.1016/j.bspc.2006.12.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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