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https://www.readbyqxmd.com/read/28211132/comparison-of-left-atrial-voltage-between-sinus-rhythm-and-atrial-fibrillation-in-association-with-electrogram-wave-form
#1
Masaharu Masuda, Masashi Fujita, Osamu Iida, Shin Okamoto, Takayuki Ishihara, Kiyonori Nanto, Takashi Kanda, Akihiro Sunaga, Takuya Tsujimura, Yasuhiro Matsuda, Takuya Ohashi, Masaaki Uematsu
BACKGROUND: The efficacy of low-voltage-guided ablation in addition to pulmonary vein (PV) isolation for atrial fibrillation (AF) has been reported with voltage mapping being performed during sinus rhythm (SR) or AF. The study aimed to compare the left atrial voltage between SR and AF in association with the electrogram wave form. METHODS: This prospective observational study included 30 consecutive patients with persistent AF. After completion of PV isolation, electrogram points were taken during both SR and AF at the identical locations evenly throughout the left atrium...
February 16, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28207381/personalized-models-of-human-atrial-electrophysiology-derived-from-endocardial-electrograms
#2
Cesare Corrado, John Whitaker, Henry Chubb, Steven Williams, Matthew Wright, Jaswinder Gill, Mark O'Neill, Steven Niederer
OBJECTIVE: Computational models represent a novel framework for understanding the mechanisms behind atrial fibrillation (AF) and offer a pathway for personalizing and optimizing treatment. The characterization of local electrophysiological properties across the atria during procedures remains a challenge. The aim of this work is to characterize the regional properties of the human atrium from multi-electrode catheter measurements. METHODS: We propose a novel method that characterizes regional electrophysiology properties by fitting parameters of an ionic model to conduction velocity and effective refractory period restitution curves obtained by a s1 s2 pacing protocol applied through a multi-electrode catheter...
May 30, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28185356/mapping-ripples-or-waves-in-atrial-fibrillation
#3
EDITORIAL
Junaid A B Zaman, Christopher A B Kowalewski, Sanjiv M Narayan
Therapy for persistent atrial fibrillation (AF) is limited by uncertainty in its mechanisms yet, unlike in organized rhythms, mechanisms for AF may vary dramatically with mapping technique. The traditional approach of drawing contour maps of AF by assigning an onset time to each electrogram reveals disordered activity in patients with permanent AF at non-arrhythmia surgery.(1,2) This article is protected by copyright. All rights reserved.
February 10, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28185348/two-independent-mapping-techniques-identify-rotational-activity-patterns-at-sites-of-local-termination-during-persistent-atrial-fibrillation
#4
Mahmood Alhusseini, David Vidmar, Gabriela L Meckler, Christopher Kowalewski, Fatemah Shenasa, Paul J Wang, Sanjiv M Narayan, Wouter-Jan Rappel
: The mechanisms for atrial fibrillation (AF) are unclear in part because diverse mapping techniques yield diverse maps ranging from stable organized sources to highly disordered waves. We hypothesized that AF mechanisms may be clarified if mapping techniques were compared in the same patients, and referenced to a clinical endpoint. We compared 2 independent AF mapping techniques in patients in whom local ablation terminated persistent AF before pulmonary vein isolation (PVI). TECHNIQUES AND RESULTS: We identified 12 patients with persistent AF (61...
February 10, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28184198/local-left-ventricular-epicardial-j-waves-and-late-potentials-in-brugada-syndrome-patients-with-inferolateral-early-repolarization-pattern
#5
Satoshi Nagase, Masamichi Tanaka, Hiroshi Morita, Koji Nakagawa, Tadashi Wada, Masato Murakami, Nobuhiro Nishii, Kazufumi Nakamura, Hiroshi Ito, Tohru Ohe, Kengo F Kusano
Background: Brugada syndrome (BrS) is characterized by J-point or ST-segment elevation on electrocardiograms (ECGs) and increased risk of ventricular fibrillation (VF). In BrS, epicardial depolarization abnormality with delayed potential on the right ventricular outflow tract is reportedly the predominant mechanism underlying VF. Yet VF occurrence is also associated with early repolarization (ER) pattern in the inferolateral ECG leads, which may represent the inferior and/or left lateral ventricular myocardium...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28174170/does-additional-electrogram-guided-ablation-after-linear-ablation-reduce-recurrence-after-catheter-ablation-for-longstanding-persistent-atrial-fibrillation-a-prospective-randomized-study
#6
Tae-Hoon Kim, Jae-Sun Uhm, Jong-Youn Kim, Boyoung Joung, Moon-Hyoung Lee, Hui-Nam Pak
BACKGROUND: Although circumferential pulmonary vein isolation (CPVI) catheter ablation may not be sufficient for long-standing persistent atrial fibrillation (L-PeAF), it is not clear which ablation strategy is beneficial in addition to CPVI. We sought to investigate whether additional complex fractionated atrial electrogram (CFAE)-guided ablation improves clinical outcomes in L-PeAF patients who exhibit continuous atrial fibrillation (AF) after CPVI and linear ablation (Line). METHODS AND RESULTS: This study enrolled 137 L-PeAF patients (71...
February 7, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28170198/differential-mechanisms-of-myocardial-conduction-slowing-by-adipose-tissue-derived-stromal-cells-derived-from-different-species
#7
Judith N Ten Sande, Nicoline W Smit, Mojtaba Parvizi, Shirley C M van Amersfoorth, Josée A Plantinga, Pascal F H M van Dessel, Jacques M T de Bakker, Marco C Harmsen, Ruben Coronel
Stem cell therapy is a promising therapeutic option to treat patients after myocardial infarction. However, the intramyocardial administration of large amounts of stem cells might generate a proarrhythmic substrate. Proarrhythmic effects can be explained by electrotonic and/or paracrine mechanisms. The narrow therapeutic time window for cell therapy and the presence of comorbidities limit the application of autologous cell therapy. The use of allogeneic or xenogeneic stem cells is a potential alternative to autologous cells, but differences in the proarrhythmic effects of adipose-derived stromal cells (ADSCs) across species are unknown...
January 2017: Stem Cells Translational Medicine
https://www.readbyqxmd.com/read/28167080/epicardial-catheter-ablation-of-ventricular-tachycardia
#8
REVIEW
Arash Aryana, André d'Avila
Over the last two decades, epicardial catheter ablation has evolved into a practical approach for treatment of ventricular tachycardia (VT). There are certain considerations when performing this procedure. First, presence of epicardial fat can diminish peak-to-peak electrogram amplitude and also impede radiofrequency energy delivery. Hence, epicardial VT ablation should be performed with cooled-tip radiofrequency using reduced irrigation flow within a relatively 'dry' pericardial milieu. Furthermore, catheter orientation is key when performing epicardial ablation...
March 2017: Cardiac Electrophysiology Clinics
https://www.readbyqxmd.com/read/28160298/fluoroless-catheter-ablation-of-cardiac-arrhythmias-a-5-year-experience
#9
Mansour Razminia, M Cameron Willoughby, Hany Demo, Hesam Keshmiri, Theodore Wang, Oliver J D'Silva, Terry A Zheutlin, Hakeem Jibawi, Paul Okumale, Richard F Kehoe
BACKGROUND: Catheter ablations have been traditionally performed with the use of fluoroscopic guidance, which exposes the patient and staff to the inherent risks of radiation. We have developed techniques to eliminate the use of fluoroscopy during cardiac ablations and have been performing completely fluoroless catheter ablations on our patients for over 5 years. METHODS: We present a retrospective analysis of the safety, efficacy, and feasibility data from 500 consecutive patients who underwent nonfluoroscopic catheter ablation, targeting a total of 639 arrhythmias, including atrioventricular reciprocating tachycardia (AVRT), atrioventricular nodal reentrant tachycardia (AVNRT), atrial tachycardia (AT), atrial fibrillation (AF), premature ventricular contractions (PVC), and ventricular tachycardia (VT)...
February 3, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28150317/electrograms-and-marker-delay-is-there-a-problem
#10
Paul Bibby, Justin Z Lee, Komandoor Srivathsan, Siva K Mulpuru
No abstract text is available yet for this article.
February 2, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/28143653/methods-accuracy-and-clinical-implications-of-atrial-fibrillation-detection-by-cardiac-implantable-electronic-devices
#11
Diana Solari, Edoardo Bertero, Roberta Miceli, Claudio Brunelli, Pietro Ameri, Marco Canepa
Atrial fibrillation (AF) is the most common arrhythmia in the developed countries and is associated with an increased risk of thromboembolic events and heart failure. Episodes of AF are often asymptomatic and intermittent, eluding diagnosis with non-continuous monitoring techniques. Cardiac implantable electronic devices (CIEDs) represent the gold standard for detecting asymptomatic AF. Improper CIED programming may however increase the risk of false-positive detection of atrial tachyarrhythmias, leading to inappropriate clinical management of patients...
January 14, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/28120237/hibernating-substrate-of-ventricular-tachycardia-a-three-dimensional-metabolic-and-electro-anatomic-assessment
#12
Ayman A Hussein, Michelle Niekoop, Vasken Dilsizian, Yousra Ghzally, Mohammed Abdulghani, Ramazan Asoglu, Wengen Chen, Mark Smith, Vincent See, Stephen R Shorofsky, Timm-Michael Dickfeld
PURPOSE: Hibernating myocardium (HM) is associated with sudden cardiac death (SCD). Little is known about the electrophysiological properties of HM and the basis of its association with SCD. We aimed to electrophysiologically characterize HM in patients with ventricular tachycardia (VT). METHODS: Endocardial voltage mapping, metabolic (18)FDG-positron emission tomography (PET) and perfusion (82)Rb, (201)Tl, or (99m)Tc scans were performed in 61 ischemic heart disease patients with VT...
January 25, 2017: Journal of Interventional Cardiac Electrophysiology: An International Journal of Arrhythmias and Pacing
https://www.readbyqxmd.com/read/28113283/identification-of-rotors-during-human-atrial-fibrillation-using-contact-mapping-and-phase-singularity-detection-technical-considerations
#13
Pawel Kuklik, Stef Zeemering, Arne van Hunnik, Bart Maesen, Laurent Pison, Dennis Lau, Jos Maessen, Piotr Podziemski, Christian Meyer, Benjamin Schaffer, Harry Crijns, Stephan Willems, Ulrich Schotten
OBJECTIVE: To explore technical challenges of phase singularity mapping during Atrial Fibrillation (AF) using direct contact electrograms. METHODS: AF mapping was performed in high-density epicardial recordings of human paroxysmal (PAF) or persistent (PersAF) (N=20 pts) AF with an array of 16x16 electrodes placed on atrial epicardium. Phase singularity (PS) points were detected using subsets of electrodes forming rings of varying size. RESULTS: PS detection using a 2x2 electrode ring identified 0...
April 15, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28108548/the-effect-of-left-ventricular-pacing-on-transmural-activation-delay-in-myopathic-human-hearts
#14
Andreu Porta-Sánchez, Paul Angaran, Stéphane Massé, Krishnakumar Nair, Talha Farid, Karthikeyan Umapathy, John Asta, Sigfus Gizurarson, Kumaraswamy Nanthakumar
AIMS: Left ventricular (LV) epicardial pacing (LVEpiP) in human myopathic hearts does not decrease global epicardial activation delay compared with right ventricular (RV) endocardial pacing (RVEndoP); however, the effect on transmural activation delay has not been evaluated. To characterize the transmural electrical activation delay in human myopathic hearts during RVEndoP and LVEpiP compared with global epicardial activation delay. METHODS AND RESULTS: Explanted hearts from seven patients (5 male, 46 ± 10 years) undergoing cardiac transplantation were Langendorff-perfused and mapped using an epicardial sock electrode array (112 electrodes) and 25 transmural plunge needles (four electrodes, 2 mm spacing), for a total of 100 unipolar transmural electrodes...
January 20, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28108547/characterising-the-difference-in-electrophysiological-substrate-and-outcomes-between-heart-failure-and-non-heart-failure-patients-with-persistent-atrial-fibrillation
#15
Shouvik K Haldar, David G Jones, Habib Khan, Sandeep Panikker, Julian W E Jarman, Charlie Butcher, Eric Lim, Gareth Wynn, Dhiraj Gupta, Wajid Hussain, Vias Markides, Tom Wong
AIMS: Characterizing the differences in substrate and clinical outcome between heart failure (HF) and non-heart failure (non-HF) patients undergoing persistent atrial fibrillation (AF) ablation. METHODS AND RESULTS: Using complex fractionated electrograms (CFE) as a surrogate marker of substrate complexity, we compared the bi-atrial substrate in patients with persistent AF with and without HF, at baseline and after ablation, to determine its impact on clinical outcome...
January 20, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28108014/electrocardiographic-spatial-loops-indicate-organization-of-atrial-fibrillation-minutes-before-ablation-related-transitions-to-atrial-tachycardia
#16
Tina Baykaner, Rishi Trikha, Junaid A B Zaman, David E Krummen, Paul J Wang, Sanjiv M Narayan
BACKGROUND: During ablation for atrial fibrillation (AF), it is challenging to anticipate transitions to organized tachycardia (AT). Defining indices of this transition may help to understand fibrillatory conduction and help track therapy. OBJECTIVE: To determine the timescale over which atrial fibrillation (AF) organizes en route to atrial tachycardia (AT) using the ECG referenced to intracardiac electrograms. METHODS: In 17 AF patients at ablation (58...
January 15, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/28104483/inhomogeneity-and-complexity-in-defining-fractionated-electrograms
#17
Lisette J M E van der Does, Natasja M S de Groot
Ablation strategies targeting areas of complex fractionated atrial electrograms are not successful for treatment of atrial fibrillation. Fractionation of atrial electrograms may have multiple causes of both pathologic and nonpathologic origin. In order to gain insight into the definitions used for determining areas of fractionation, a literature search was performed using a systematic approach. A PubMed search for studies describing fractionation during human atrial electrophysiologic measurements resulted in 348 articles that were screened for new definitions of fractionation...
January 17, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28104482/device-pacing-diagnostics-overestimate-effective-cardiac-resynchronization-therapy-pacing-results-of-the-holter-for-efficacy-analysis-of-crt-ol%C3%A3-crt-study
#18
Antonio Hernández-Madrid, Domenico Facchin, Ruth Nicholson Klepfer, Subham Ghosh, Roberto Matía, Javier Moreno, Alessandro Locatelli
BACKGROUND: A high percentage of biventricular (BiV) or left ventricular (LV) pacing in cardiac resynchronization therapy (CRT) devices has been associated with superior clinical outcomes. However, the percent ventricular (%V) pacing reported by CRT devices simply indicates the number of paces the device has delivered and not the proportion of pacing that has captured the LV effectively. OBJECTIVE: The purpose of this study was to determine whether a beat-by-beat evaluation of effective pacing would provide a more accurate evaluation of CRT delivery...
January 17, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28104480/the-effect-of-spatial-resolution-and-filtering-on-mapping-cardiac-fibrillation
#19
Benjamin King, Andreu Porta-Sánchez, Stéphane Massé, Nima Zamiri, Krishanand Balasundaram, Marjan Kusha, Nicholas Jackson, Shouvik Haldar, Karthikeyan Umapathy, Kumaraswamy Nanthakumar
BACKGROUND: Endocardial mapping tools use variable inter-electrode resolution whilst body surface mapping tools use narrow band pass filtering (BPF) to map fibrillatory mechanisms established by high resolution optical imaging. OBJECTIVES: To study the effect of resolution and BPF on the underlying mechanism being mapped. METHODS: Hearts from 14 healthy New Zealand white rabbits were Langendorff perfused. We studied the effect of spatial resolution and BPF on the location and characterization of rotors, by comparing phase singularities (PS) detected by high resolution un-filtered optical maps (OM), of fibrillating myocardium with decimated and filtered maps with simulated electrode spacing of 2, 5 and 8mm...
January 16, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28104073/af-ablation-guided-by-spatiotemporal-electrogram-dispersion%C3%A2-without-pulmonary-vein-isolation-a-wholly-patient-tailored-approach
#20
Julien Seitz, Clément Bars, Guillaume Théodore, Sylvain Beurtheret, Nicolas Lellouche, Michel Bremondy, Ange Ferracci, Jacques Faure, Guillaume Penaranda, Masatoshi Yamazaki, Uma Mahesh R Avula, Laurence Curel, Sabrina Siame, Omer Berenfeld, André Pisapia, Jérôme Kalifa
BACKGROUND: The use of intracardiac electrograms to guide atrial fibrillation (AF) ablation has yielded conflicting results. OBJECTIVES: The authors evaluated the usefulness of spatiotemporal dispersion, a visually recognizable electric footprint of AF drivers, for the ablation of all forms of AF. METHODS: The authors prospectively enrolled 105 patients admitted for AF ablation. AF was sequentially mapped in both atria with a 20-pole PentaRay catheter...
January 24, 2017: Journal of the American College of Cardiology
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