keyword
Keywords frequency domain atrial fibril...

frequency domain atrial fibrillation ablation

https://read.qxmd.com/read/21332871/time-and-frequency-domain-characteristics-of-atrial-electrograms-during-sinus-rhythm-and-atrial-fibrillation
#21
COMPARATIVE STUDY
Sheng-Hsiung Chang, Magnus Ulfarsson, Aman Chugh, Kentaro Yoshida, Krit Jongnarangsin, Thomas Crawford, Eric Good, Frank Pelosi, Frank Bogun, Fred Morady, Hakan Oral
BACKGROUND: Complex fractionated atrial electrograms (CFAE) have been considered to be helpful during catheter ablation of atrial fibrillation (AF). The purpose of this study was to analyze the characteristics of CFAEs recorded during sinus rhythm (SR) and AF, and to determine their relationship to perpetuation of AF and clinical outcome. METHODS AND RESULTS: Antral pulmonary vein isolation (APVI) was performed in 34 consecutive patients (age = 59 ± 10 years) with paroxysmal AF who presented in SR...
August 2011: Journal of Cardiovascular Electrophysiology
https://read.qxmd.com/read/21208232/frequency-domain-and-time-complex-analyses-manifest-low-correlation-and-temporal-variability-when-calculating-activation-rates-in-atrial-fibrillation-patients
#22
JOURNAL ARTICLE
Angelo B Biviano, James Coromilas, Edward J Ciaccio, William Whang, Kathleen Hickey, Hasan Garan
BACKGROUND: Atrial fibrillation (AF) activation rates have been calculated using both frequency domain and time complex analyses. Direct comparisons of these methods are limited. We report: (1) their correlation when measuring AF activation rates, (2) comparisons of recording durations required to minimize variability, and (3) differences in the temporal reproducibility. METHODS: AF activation rates were calculated using domain frequency (DF) (via fast Fourier transform) and time complex (TC) (via beat-to-beat activation measurements) analyses...
May 2011: Pacing and Clinical Electrophysiology: PACE
https://read.qxmd.com/read/20803171/a-novel-approach-to-propagation-pattern-analysis-in-intracardiac-atrial-fibrillation-signals
#23
JOURNAL ARTICLE
Ulrike Richter, Luca Faes, Alessandro Cristoforetti, Michela Masè, Flavia Ravelli, Martin Stridh, Leif Sörnmo
The purpose of this study is to investigate propagation patterns in intracardiac signals recorded during atrial fibrillation (AF) using an approach based on partial directed coherence (PDC), which evaluates directional coupling between multiple signals in the frequency domain. The PDC is evaluated at the dominant frequency of AF signals and tested for significance using a surrogate data procedure specifically designed to assess causality. For significantly coupled sites, the approach allows also to estimate the delay in propagation...
January 2011: Annals of Biomedical Engineering
https://read.qxmd.com/read/20673913/toward-discerning-the-mechanisms-of-atrial-fibrillation-from-surface-electrocardiogram-and-spectral-analysis
#24
JOURNAL ARTICLE
Omer Berenfeld
Atrial fibrillation (AF) is the main cause of stroke and the most common sustained arrhythmia, afflicting about 2.3 million Americans. Clinical treatment and management of AF would benefit from a noninvasive and global assessment of the arrhythmia; however, that avenue seems currently limited in part by our poor understanding of arrhythmia itself. Experimental studies of AF in the isolated sheep heart demonstrated that high-frequency sources in the posterior wall of the left atrium drive the fibrillatory activity throughout both atria...
November 2010: Journal of Electrocardiology
https://read.qxmd.com/read/20022876/increase-in-organization-index-predicts-atrial-fibrillation-termination-with-flecainide-post-ablation-spectral-analysis-of-intracardiac-electrograms
#25
JOURNAL ARTICLE
Jiun Tuan, Faizel Osman, Mohamed Jeilan, Suman Kundu, Rajkumar Mantravadi, Peter J Stafford, G André Ng
AIMS: The mechanism of the action of flecainide in the termination of human atrial fibrillation (AF) is not fully understood. We studied the acute effects of flecainide on AF electrograms in the time and frequency domain to identify factors associated with AF termination. METHODS AND RESULTS: Patients who were still in AF at the end of catheter ablation for AF were given intravenous flecainide. Dominant frequency (DF) and organization index (OI) were obtained by fast Fourier transform of electrograms from the coronary sinus catheter over 10 s in AF, before and after flecainide infusion...
April 2010: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://read.qxmd.com/read/19968929/frequency-domain-versus-time-domain-analysis-optimizing-complex-fractionated-atrial-electrogram-identification-for-atrial-fibrillation-ablation
#26
EDITORIAL
Stanley Nattel
No abstract text is available yet for this article.
October 2009: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://read.qxmd.com/read/19968928/complex-fractionated-atrial-electrograms-properties-of-time-domain-versus-frequency-domain-methods
#27
JOURNAL ARTICLE
Krzysztof R Grzeda, Sami F Noujaim, Omer Berenfeld, José Jalife
BACKGROUND: Complex fractionated atrial electrograms (CFAEs) are thought to identify high-frequency electrical sources and have become an important target for radiofrequency ablation of atrial fibrillation (AF). Methods used to identify CFAEs and locate suitable ablation sites usually depend on subjective analysis of the electrograms but may also involve objective, computer-based paradigms through either time- or frequency-domain approaches. METHODS: We generated a set of simulated test electrograms, which were defined by a combination of a basic cycle length, phase-resetting noise, and phase-preserving noise, accounting for far-field effects...
October 2009: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://read.qxmd.com/read/19008240/evaluation-of-spatiotemporal-organization-of-persistent-atrial-fibrillation-with-time-and-frequency-domain-measures-in-humans
#28
JOURNAL ARTICLE
Rolf Franck Berntsen, Alan Cheng, Hugh Calkins, Ronald D Berger
AIMS: Areas with complex fractionated electrograms are commonly targeted during ablation of persistent atrial fibrillation (AF). These signals are, however, found in most sampled areas of the left atrium (LA), implying the need for further differentiation. METHODS AND RESULTS: Electrograms were recorded over 60 s at eight different LA endocardial sites in 10 patients with persistent AF, using a fully automated algorithm. These were analysed in sequential 2 s segments for activity, mean amplitude, continuous activity percentage, and dominant frequency (DF)...
March 2009: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://read.qxmd.com/read/18936041/incidence-timing-and-characteristics-of-acute-changes-in-heart-rate-during-ongoing-circumferential-pulmonary-vein-isolation
#29
RANDOMIZED CONTROLLED TRIAL
Stefan Ketels, Richard Houben, Katarina Van Beeumen, Rene Tavernier, Mattias Duytschaever
AIMS: Previous studies showed that catheter ablation of atrial fibrillation (AF) results in vagal denervation with an increase in average heart rate (HR) and a reduced overall HR variability (HRV) at follow-up. We analysed acute ablation-induced changes in HR and short-term HRV during percutaneous circumferential pulmonary vein isolation (CPVI). We also studied whether observed changes were predictors of successful outcome after first CPVI. METHODS AND RESULTS: A total of 46 patients (35 men, 55 +/- 10 years) undergoing CARTO and computed tomography-guided CPVI for symptomatic AF were studied...
December 2008: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://read.qxmd.com/read/18462334/complex-electrograms-within-the-coronary-sinus-time-and-frequency-domain-characteristics-effects-of-antral-pulmonary-vein-isolation-and-relationship-to-clinical-outcome-in-patients-with-paroxysmal-and-persistent-atrial-fibrillation
#30
JOURNAL ARTICLE
Kentaro Yoshida, Magnus Ulfarsson, Hiroshi Tada, Aman Chugh, Eric Good, Michael Kuhne, Thomas Crawford, Jean F Sarrazin, Nagib Chalfoun, Darryl Wells, Krit Jongnarangsin, Frank Pelosi, Frank Bogun, Fred Morady, Hakan Oral
BACKGROUND: The mechanistic and clinical significance of complex fractionated atrial electrograms (CFAE) in the coronary sinus (CS) has been unclear. METHODS AND RESULTS: Antral pulmonary vein isolation (APVI) was performed in 77 patients with paroxysmal (32) or persistent AF (45). CS electrograms recorded for 60 seconds before and after APVI were analyzed in the time- and frequency-domains. Dominant frequency (DF), complexity index (CI: change in polarity of depolarization), and fractionation index (FI: change in direction of depolarization slope) were determined...
October 2008: Journal of Cardiovascular Electrophysiology
https://read.qxmd.com/read/17959699/quantifying-fractionation-and-rate-in-human-atrial-fibrillation-using-monophasic-action-potentials-implications-for-substrate-mapping
#31
JOURNAL ARTICLE
Sanjiv M Narayan, Michael R Franz
AIMS: To use monophasic action potentials (MAPs) to better assess the rate and the presence of fractionated electrograms during the mapping of atrial fibrillation (AF). Substrate mapping is increasingly central to AF ablation. However, traditional bipolar signals poorly represent waveform shape, making it unclear whether fractionation reflects local waveform variations, true electrogram fragmentation, or noise, and raising issues on whether their spectral dominant frequencies (DFs) accurately estimate AF rate...
November 2007: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://read.qxmd.com/read/17711441/validation-of-the-frequency-spectra-obtained-from-the-noncontact-unipolar-electrograms-during-atrial-fibrillation
#32
COMPARATIVE STUDY
Yenn-Jiang Lin, Satoshi Higa, Tsair Kao, Han-Wen Tso, Ching-Tai Tai, Shih-Lin Chang, Li-Wei Lo, Wanwarang Wongcharoen, Shih-Ann Chen
INTRODUCTION: Noncontact mapping (NCM) can record virtual unipolar electrograms (Egs) from multiple sites simultaneously; therefore, it has the potential to perform simultaneous frequency mapping during atrial fibrillation (AF). The aim of this study was to validate the frequency spectra of the noncontact unipolar Egs in both atria. METHODS: This study enrolled 12 patients (age = 61 +/- 16 years) with paroxysmal or persistent AF who underwent catheter ablation guided by NCM...
November 2007: Journal of Cardiovascular Electrophysiology
https://read.qxmd.com/read/16461834/mechanisms-of-wave-fractionation-at-boundaries-of-high-frequency-excitation-in-the-posterior-left-atrium-of-the-isolated-sheep-heart-during-atrial-fibrillation
#33
JOURNAL ARTICLE
Jérôme Kalifa, Kazuhiko Tanaka, Alexey V Zaitsev, Mark Warren, Ravi Vaidyanathan, David Auerbach, Sandeep Pandit, Karen L Vikstrom, Robert Ploutz-Snyder, Arkadzi Talkachou, Felipe Atienza, Gérard Guiraudon, José Jalife, Omer Berenfeld
BACKGROUND: High-frequency fractionated electrograms recorded during atrial fibrillation (AF) in the posterior left atrium (PLA) and elsewhere are being used as target sites for catheter ablation. We tested the hypothesis that highly periodic electric waves emerging from AF sources at or near the PLA give rise to the most fractionated activity in adjacent locations. METHODS AND RESULTS: Sustained AF was induced in 8 isolated sheep hearts (0.5 micromol/L acetylcholine)...
February 7, 2006: Circulation
https://read.qxmd.com/read/15683504/changes-in-autonomic-nervous-activity-after-catheter-ablation-of-atrial-tachycardia-arising-from-the-atrioventricular-annulus
#34
JOURNAL ARTICLE
Mariko Kongo, Eitaro Fujii, Koji Matsuoka, Fumiya Uchida, Setsuya Okubo, Atsunobu Kasai, Chikaya Omichi, Naoki Isaka, Takeshi Nakano
Radiofrequency (RF) catheter ablation of supraventricular tachycardias causes local parasympathetic denervation. This study used heart rate variability (HRV) to evaluate the effects of ablation of atrial tachycardia (AT) arising from the atrioventricular annulus (AVAT) on autonomic function. Ten patients with AVAT were referred for ablation (group AT) and compared with 8 patients with paroxysmal atrial fibrillation who underwent PV isolation (group Paf), and 13 patients with idiopathic ventricular tachycardia successfully treated by ablation (group VT)...
January 2005: Pacing and Clinical Electrophysiology: PACE
https://read.qxmd.com/read/14574019/experimental-and-clinical-af-mechanisms-bridging-the-divide
#35
REVIEW
José Jalife
There is general agreement that AF is most likely a reentrant rhythm disturbance. However, the precise pathophysiological bases for its initiation and maintenance have not been fully resolved. In the original description of the multiple wavelet hypothesis of atrial fibrillation, as put forward by Moe et al. and later substantiated by Allessie et al., the wavelets were thought to move randomly throughout the atria. However, more recent studies that have applied high resolution mapping of wave propagation and rigorous analyses in the time and frequency domains to long episodes of AF, have provided evidence that atrial fibrillation is not random, but is accompanied by a high degree of spatiotemporal periodicity...
October 2003: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
https://read.qxmd.com/read/11294170/fluctuation-in-autonomic-tone-is-a-major-determinant-of-sustained-atrial-arrhythmias-in-patients-with-focal-ectopy-originating-from-the-pulmonary-veins
#36
JOURNAL ARTICLE
M Zimmermann, D Kalusche
INTRODUCTION: This study was designed to analyze dynamic changes in autonomic tone preceding the onset of sustained atrial arrhythmias in patients with focal atrial fibrillation (AF) to determine why patients with frequent discharge from the arrhythmogenic foci develop sustained AF. METHODS AND RESULTS: Holter tapes from 13 patients (10 men and 3 women; mean age 53 +/- 5 years) with paroxysmal "lone" AF (mean 18 +/- 13 episodes per week) and a proven focal origin (pulmonary veins in all cases) were analyzed...
March 2001: Journal of Cardiovascular Electrophysiology
https://read.qxmd.com/read/10577997/alterations-of-heart-rate-variability-after-radiofrequency-catheter-ablation-of-focal-atrial-fibrillation-originating-from-pulmonary-veins
#37
COMPARATIVE STUDY
M H Hsieh, C W Chiou, Z C Wen, C H Wu, C T Tai, C F Tsai, Y A Ding, M S Chang, S A Chen
BACKGROUND: Transient sinus bradycardia and hypotension have been reported as complications during radiofrequency (RF) ablation of focal atrial fibrillation (AF) originating from pulmonary veins (PVs). This study used heart rate variability (HRV) to evaluate the effects of focal PVs ablation on autonomic function. METHODS AND RESULTS: Thirty-seven patients with paroxysmal AF were referred for ablation. The study group included 30 patients who underwent transseptal ablation of PVs, and the control group included 7 patients who underwent the transseptal procedure without ablation...
November 30, 1999: Circulation
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