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https://www.readbyqxmd.com/read/29166717/-left-atrial-appendage-volume-is-a-valuable-predictor-of-atrial-fibrillation-recurrence-after-radiofrequency-catheter-ablation
#1
G A Zheng, C Y Lin, L Weng, J D Chen
Objective: To investigate the association between the left atrial appendage (LAA) volume and atrial fibrillation (AF) recurrence after radiofrequency catheter ablation. Methods: We prospectively enrolled sixty-two patients with AF (40 cases with paroxysmal AF, 22 cases with persistent AF) who successfully underwent a first AF catheter ablation and had performed contrast-enhanced cardiac computed tomography (CT) prior to the procedure to measure LAA volumes in our hospital from January 2012 to August 2015. Circumferential pulmonary vein isolation was performed under the guidance of three-dimension mapping system (CARTO system)...
November 24, 2017: Zhonghua Xin Xue Guan Bing za Zhi
https://www.readbyqxmd.com/read/29162282/interruption-of-cardiac-resynchronization-therapy-by-atrial-premature-complexes
#2
S Serge Barold, Andreas Kucher
Biotronik devices used for cardiac resynchronization therapy (CRT) combined with defibrillation function (CRT-D) are capable of left ventricular (LV) sensing. Under certain circumstances, LV sensing may cause loss of CRT. The third generation of the Biotronik i-family CRT-Ds enables the recording of event-triggered tracings of the electrogram particularly those involving "CRT pacing interrupt" episodes. We report three cases of a sudden "CRT pacing interrupt" initiated by an atrial premature complex. This was caused by realignment of the LV timing cycles induced by the APCs whereupon LV pacing was inhibited and a self-perpetuating desynchronization process was initiated...
October 21, 2017: Journal of Electrocardiology
https://www.readbyqxmd.com/read/29146275/beat-to-beat-variations-in-activation-recovery-interval-derived-from-the-right-ventricular-electrogram-can-monitor-arrhythmic-risk-under-anesthetic-and-awake-conditions-in-the-canine-chronic-atrioventricular-block-model
#3
Sofieke C Wijers, David J Sprenkeler, Alexandre Bossu, Albert Dunnink, Jet D M Beekman, Rosanne Varkevisser, Alfonso Aranda Hernández, Mathias Meine, Marc A Vos
BACKGROUND: In the chronic atrioventricular block (CAVB) dog model, beat-to-beat variation of repolarization in the left ventricle (LV) quantified as short-term variability of the left monophasic action potential duration (STVLVMAPD) increases abruptly upon challenge with a pro arrhythmic drug. This increase occurs before the first ectopic beat (EB), specifically in subjects that demonstrate subsequent repetitive Torsade de Pointes arrhythmias (TdP). OBJECTIVE: Demonstrate that STV is feasible to monitor arrhythmic risk through the use of the intracardiac electrogram (EGM) derived from the right ventricle (RV) lead from pacemakers or implantable cardioverter defibrillators (ICD)...
November 13, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/29141843/stable-sr-electrophysiological-substrate-ablation-in-the-left-atrium-during-sinus-rhythm-for-the-treatment-of-nonparoxysmal-atrial-fibrillation-a-prospective-multicenter-randomized-clinical-trial
#4
Bing Yang, Chenyang Jiang, Yazhou Lin, Gang Yang, Huimin Chu, Heng Cai, Fengmin Lu, Xianzhang Zhan, Jian Xu, Xinhua Wang, Chi-Keong Ching, Balbir Singh, Young-Hoon Kim, Minglong Chen
BACKGROUND: Circumferential pulmonary vein isolation (CPVI) alone or combined with adjuvant substrate modifications is unsatisfactory for atrial fibrillation (AF) control in nonparoxysmal AF patients. Ablation targeting the fibrotic areas after CPVI (STABLE-SR [Electrophysiological Substrate Ablation in the Left Atrium During Sinus Rhythm]) is a newly evolved substrate modification strategy. METHODS AND RESULTS: In this multicenter, randomized clinical trial, 229 symptomatic nonparoxysmal AF patients were 1:1 randomized to STABLE-SR group (n=114) or conventional STEPWISE group (n=115)...
November 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29133380/atrial-substrate-and-triggers-of-paroxysmal-atrial-fibrillation-in-patients-with-obstructive-sleep-apnea
#5
Elad Anter, Luigi Di Biase, Fernando M Contreras-Valdes, Carola Gianni, Sanghamitra Mohanty, Cory M Tschabrunn, Juan F Viles-Gonzalez, Eran Leshem, Alfred E Buxton, Guy Kulbak, Rim N Halaby, Peter J Zimetbaum, Jonathan W Waks, Robert J Thomas, Andrea Natale, Mark E Josephson
BACKGROUND: Obstructive sleep apnea (OSA) is associated with atrial remodeling, atrial fibrillation (AF), and increased incidence of arrhythmia recurrence after pulmonary vein (PV) isolation. We aimed to characterize the atrial substrate, including AF triggers in patients with paroxysmal AF and OSA. METHODS AND RESULTS: In 86 patients with paroxysmal AF (43 with ≥moderate OSA [apnea-hypopnea index ≥15] and 43 without OSA [apnea-hypopnea index <5]), right atrial and left atrial voltage distribution, conduction velocities, and electrogram characteristics were analyzed during atrial pacing...
November 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29130071/the-electrophysiological-substrate-of-early-repolarization-syndrome-noninvasive-mapping-in-patients
#6
Junjie Zhang, Mélèze Hocini, Maria Strom, Phillip S Cuculich, Daniel H Cooper, Frédéric Sacher, Michel Haïssaguerre, Yoram Rudy
Background: The early repolarization (ER) pattern is a common ECG finding. Recent studies established a definitive clinical association between ER and fatal ventricular arrhythmias. However, the arrhythmogenic substrate of ER in the intact human heart has not been characterized. Objectives: To map the epicardial electrophysiological (EP) substrate in ER syndrome patients using noninvasive Electrocardiographic Imaging (ECGI), and to characterize substrate properties that support arrhythmogenicity...
August 2017: JACC. Clinical Electrophysiology
https://www.readbyqxmd.com/read/29127709/pulmonary-damage-following-right-ventricular-outflow-tachycardia-ablation-in-a-child-when-electroanatomical-mapping-isn-t-good-enough
#7
Neha Bansal, Daisuke Kobayashi, Peter P Karpawich
A 14-year-old female was referred for severe pulmonary valve insufficiency after undergoing radiofrequency ablation for a right ventricular outflow tract tachycardia that originated in the proximal pulmonary artery at 10 years of age. Clinical records indicated that ablation was guided solely by electrograms and electroanatomical mapping. Due to myocardial tissue extensions, mapping failed to identify the level of the pulmonary valve annulus, which resulted in delivery of energy on the valve proper and into the pulmonary artery...
November 11, 2017: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/29107175/entrapment-of-focal-atrial-tachycardia-using-cryoballoon-ablation-sinus-rhythm-in-the-left-atrium-and-ongoing-atrial-tachycardia-in-the-left-atrial-appendage
#8
Hikmet Yorgun, Uğur Canpolat, Banu Evranos, Kudret Aytemir
Left atrial appendage (LAA) is a well-known source of focal atrial tachycardias (AT). Although radio-frequency (RF) energy is the most commonly used technique in such cases, there was an option other than epicardial approach when RF technique fails. Cryoballoon technology is primarily developed to be used for pulmonary vein isolation (PVI). Also, there was no report regarding the isolation of LAA by using cryo-balloon in patients with focal AT. In this case, for the first time in the literature, we successfully isolated the LAA because of failed attempts of RF ablation for focal AT in whom the surface electrogram showed a sinus rhythm while arrhythmia continues inside the LAA...
October 28, 2017: Indian Pacing and Electrophysiology Journal
https://www.readbyqxmd.com/read/29106563/tailoring-device-settings-in-cardiac-resynchronization-therapy-using-electrograms-from-pacing-electrodes
#9
Elien B Engels, Masih Mafi-Rad, Ben J M Hermans, Alfonso Aranda, Antonius M W van Stipdonk, Michiel Rienstra, Coert O S Scheerder, Alexander H Maass, Frits W Prinzen, Kevin Vernooy
Aims: Left ventricular (LV) fusion pacing appears to be at least as beneficial as biventricular pacing in cardiac resynchronization therapy (CRT). Optimal LV fusion pacing critically requires adjusting the atrioventricular (AV)-delay to the delay between atrial pacing and intrinsic right ventricular (RV) activation (Ap-RV). We explored the use of electrogram (EGM)-based vectorloop (EGMV) derived from EGMs of implanted pacing leads to achieve optimal LV fusion pacing and to compare it with conventional approaches...
June 30, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29106546/clinical-validation-of-automatic-local-activation-time-annotation-during-focal-premature-ventricular-complex-ablation-procedures
#10
Juan Acosta, David Soto-Iglesias, Juan Fernández-Armenta, Manuel Frutos-López, Beatriz Jáuregui, Eduardo Arana-Rueda, Marcos Fernández, Diego Penela, Alejandro Alcaine, Lucas Cano, Alonso Pedrote, Antonio Berruezo
Aims: Current navigation systems incorporate algorithms for automatic identification of local activation time (LAT). However, data about their utility and accuracy in premature ventricular complex (PVC) ablation procedures are scarce. This study analyses the accuracy of an algorithmic method based on automatic annotation of the maximal negative slope of the unipolar electrogram within the window demarcated by the bipolar electrogram compared with conventional manual annotation during PVC ablation procedures...
November 2, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/29091329/repolarization-abnormalities-unmasked-with-exercise-in-sudden-cardiac-death-survivors-with-structurally-normal-hearts
#11
Kevin Mw Leong, Fu Siong Ng, Caroline Roney, Christopher Cantwell, Matthew J Shun-Shin, Nicholas Wf Linton, Zachary I Whinnett, David C Lefroy, D Wyn Davies, Sian E Harding, Phang Boon Lim, Darrel Francis, Nicholas S Peters, Amanda M Varnava, Prapa Kanagaratnam
BACKGROUND: Models of cardiac arrhythmogenesis predict that non-uniformity in repolarization and/or depolarization promotes ventricular fibrillation and is modulated by autonomic tone, but this is difficult to evaluate in patients. We hypothesize that such spatial heterogeneities would be detected by non-invasive ECG imaging (ECGi) in sudden cardiac death (SCD) survivors with structurally normal hearts under physiological stress. METHODS: ECGi was applied to 11 SCD survivors, 10 low-risk Brugada Syndrome patients (BrS) and 10 controls undergoing exercise treadmill testing...
November 1, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/29075204/human-cardiomyocyte-progenitor-cells-in-co-culture-with-rat-cardiomyocytes-form-a-pro-arrhythmic-substrate-evidence-for-two-different-arrhythmogenic-mechanisms
#12
Nicoline W Smit, Lucia Cócera Ortega, Anna M D Végh, Veronique M F Meijborg, Anke M Smits, Mischa Klerk, Anke J M Tijsen, Hanno L Tan, Marie-José H T Goumans, Gerard J J Boink, Ruben Coronel
Background: Cardiomyocyte progenitor cells (CMPCs) are a promising cell source for regenerative cell therapy to improve cardiac function after myocardial infarction. However, it is unknown whether undifferentiated CMPCs have arrhythmogenic risks. We investigate whether undifferentiated, regionally applied, human fetal CMPCs form a pro-arrhythmic substrate in co-culture with neonatal rat ventricular myocytes (NRVMs). Method: Unipolar extracellular electrograms, derived from micro-electrode arrays (8 × 8 electrodes) containing monolayers of NRVMs (control), or co-cultures of NRVMs and locally seeded CMPCs were used to determine conduction velocity and the incidence of tachy-arrhythmias...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29075201/virtual-in-silico-modeling-guided-catheter-ablation-predicts-effective-linear-ablation-lesion-set-for-longstanding-persistent-atrial-fibrillation-multicenter-prospective-randomized-study
#13
Jaemin Shim, Minki Hwang, Jun-Seop Song, Byounghyun Lim, Tae-Hoon Kim, Boyoung Joung, Sung-Hwan Kim, Yong-Seog Oh, Gi-Byung Nam, Young Keun On, Seil Oh, Young-Hoon Kim, Hui-Nam Pak
Objective: Radiofrequency catheter ablation for persistent atrial fibrillation (PeAF) still has a substantial recurrence rate. This study aims to investigate whether an AF ablation lesion set chosen using in-silico ablation (V-ABL) is clinically feasible and more effective than an empirically chosen ablation lesion set (Em-ABL) in patients with PeAF. Methods: We prospectively included 108 patients with antiarrhythmic drug-resistant PeAF (77.8% men, age 60.8 ± 9.9 years), and randomly assigned them to the V-ABL (n = 53) and Em-ABL (n = 55) groups...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29072995/which-side-are-you-on-deducing-the-chamber-of-origin-of-atrial-tachycardia
#14
Raja J Selvaraj, Krishna Sarin, Raveendranath Veeramani
Atrial arrhythmias rising from the regions of the atria that are in close proximity to each other may pose a challenge in identifying the chamber to map and ablate in. In this report, we discuss a patient with left atrial tachycardia which initially mimicked right atrial tachycardia. We discuss the origins of the abnormal electrograms in the right atrium and how this provides a general understanding of the mechanism of double potentials.
March 2017: Indian Pacing and Electrophysiology Journal
https://www.readbyqxmd.com/read/29072796/atrial-tachycardias-cause-or-effect-with-ablation-of-persistent-atrial-fibrillation
#15
Seigo Yamashita, Darren A Hooks, Ashok Shah, Jatin Relan, Ghassen Cheniti, Takeshi Kitamura, Benjamin Berte, Saagar Mahida, Jean-Marc Sellal, Nora Al Jefairi, Antonio Frontera, Sana Amraoui, Arnaud Denis, Nicolas Derval, Frédéric Sacher, Hubert Cochet, Rémi Dubois, Mélèze Hocini, Michel Haïssaguerre, George Klein, Pierre Jaïs
INTRODUCTION: It is largely believed that atrial tachycardias (ATs) encountered during ablation of persistent atrial fibrillation (PsAF) are a byproduct of ablative lesions. We aimed to explore the alternative hypothesis that they may be priori drivers of AF remaining masked until other AF sources are reduced or eliminated. METHODS AND RESULTS: Radiofrequency ablation of fibrillatory drivers mapped by electrocardiographic imaging (ECGI; ECVUEۛ, Cardioinsight Technologies, US) terminated PsAF in 198(73%) out of 270 patients (61±10y, 9±9 m)...
October 26, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/29060569/intracardiac-electrogram-envelope-detection-during-atrial-fibrillation-using-fast-orthogonal-search
#16
J Hashemi, M H Shariat, D Redfearn
The performance of any intracardiac electrogram processing method is limited by the accuracy of its activation detection approach. The most common activation detection approaches in the literature aim to find the highest peak in the activation envelope disregarding the start and end points. However, the duration of the activation can be used to extract useful information such as wave collisions. In this work, we propose a novel orthogonal based approach for fast and accurate estimation of the start and end of the activations (activation envelope) in intracardiac recordings during atrial fibrillation...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29060281/an-intracardiac-electrogram-model-to-bridge-virtual-hearts-and-implantable-cardiac-devices
#17
Weiwei Ai, Nitish Patel, Partha Roop, Avinash Malik, Nathan Allen, Mark L Trew
Virtual heart models have been proposed to enhance the safety of implantable cardiac devices through closed loop validation. To communicate with a virtual heart, devices have been driven by cardiac signals at specific sites. As a result, only the action potentials of these sites are sensed. However, the real device implanted in the heart will sense a complex combination of near and far-field extracellular potential signals. Therefore many device functions, such as blanking periods and refractory periods, are designed to handle these unexpected signals...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29038101/influence-of-intramyocardial-adipose-tissue-on-the-accuracy-of-endocardial-contact-mapping-of-the-chronic-myocardial-infarction-substrate
#18
Rahul Samanta, Saurabh Kumar, William Chik, Pierre Qian, Michael A Barry, Sara Al Raisi, Abhishek Bhaskaran, Melad Farraha, Fazlur Nadri, Eddy Kizana, Aravinda Thiagalingam, Pramesh Kovoor, Jim Pouliopoulos
BACKGROUND: Recent studies have demonstrated that intramyocardial adipose tissue (IMAT) may contribute to ventricular electrophysiological remodeling in patients with chronic myocardial infarction. Using an ovine model of myocardial infarction, we aimed to determine the influence of IMAT on scar tissue identification during endocardial contact mapping and optimal voltage-based mapping criteria for defining IMAT dense regions. METHOD AND RESULTS: In 7 sheep, left ventricular endocardial and transmural mapping was performed 84 weeks (15-111 weeks) post-myocardial infarction...
October 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29035207/novel-quantitative-analytical-approaches-for-rotor-identification-and-associated-implications-for-mapping
#19
Elizabeth M Annoni, Shivaram Poigai Arunachalam, Suraj Kapa, Siva K Mulpuru, Paul A Friedman, Elena G Talkachova
OBJECTIVE: Clinical studies identifying rotors confirming these sites for ablation in treating cardiac arrhythmias have had inconsistent results with the current analysis techniques available. The aim of this study is to evaluate four new signal analysis approaches - multiscale frequency (MSF), Shannon entropy (SE), Kurtosis (Kt), and multiscale entropy (MSE) - in their ability to identify the pivot point of rotors. METHODS: Optical mapping movies of ventricular tachycardia were used to evaluate the performance and robustness of SE, Kt, MSF and MSE techniques with respect to several clinical limitations: decreased time duration, reduced spatial resolution, and the presence of meandering rotors...
October 16, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/29030379/right-ventricular-pacing-increases-risk-of-appropriate-implantable-cardioverter-defibrillator-shocks-asymmetrically-an-analysis-of-the-altitude-database
#20
Edmond M Cronin, Paul Jones, Milan C Seth, Niraj Varma
BACKGROUND: Right ventricular pacing (RVP) increases risk of atrial fibrillation in patients with implantable cardioverter-defibrillators (ICDs), but ventricular proarrhythmia is less clear. We analyzed a large remote monitoring database to assess this question. METHODS AND RESULTS: Patients with single- or dual-chamber ICDs, engaged in remote monitoring for at least 6 months and with unchanged tachycardia programming, were included. %RVP was derived for each weekly transmission...
October 2017: Circulation. Arrhythmia and Electrophysiology
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