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https://www.readbyqxmd.com/read/29133381/endocardial-unipolar-voltage-maps-to-identify-epicardial-circuits-during-ventricular-tachycardia-ablation-in-chagasic-cardiomyopathy-when-the-pot-of-gold-may-not-be-at-the-other-end-of-the-rainbow
#1
EDITORIAL
André Zimerman, Juan F Viles-Gonzalez, André d'Avila
No abstract text is available yet for this article.
November 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29133379/ventricular-tachycardia-in-the-setting-of-chagasic-cardiomyopathy-use-of-voltage-mapping-to-characterize-endoepicardial-nonischemic-scar-distribution
#2
Richard Soto-Becerra, Victor Bazan, William Bautista, Federico Malavassi, Jhancarlo Altamar, Juan David Ramirez, Arlen Everth, David J Callans, Francis E Marchlinski, Diego Rodríguez, Fermin C García, Luis C Sáenz
BACKGROUND: Chagasic cardiomyopathy (CC) is the most frequent nonischemic substrate causing left ventricular (LV) tachycardia in Latin America. Systematic characterization of the LV epicardial/endocardial scar distribution and density in CC has not been performed. Additionally, the usefulness of unipolar endocardial electroanatomic mapping to identify epicardial scar has not been assessed in this setting. METHODS AND RESULTS: Nineteen patients with CC undergoing detailed epicardial and endocardial LV tachycardia mapping and ablation were included...
November 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29106546/clinical-validation-of-automatic-local-activation-time-annotation-during-focal-premature-ventricular-complex-ablation-procedures
#3
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/29094471/antifibrillatory-effects-of-renal-denervation-on-ventricular-fibrillation-in-a-canine-model-of-pacing-induced-heart-failure
#4
Qingzhi Luo, Qi Jin, Ning Zhang, Shangwei Huang, Yanxin Han, Changjian Lin, Tianyou Ling, Kang Chen, Wenqi Pan, Liqun Wu
This study investigated the effects of renal denervation (RDN) on vulnerability to ventricular fibrillation (VF) and ventricular electrical properties in a canine model of pacing-induced heart failure (HF). Eighteen beagles were divided into the following three groups: control (n = 6), HF (n = 6) and HF+RDN (n = 6). HF was induced by rapid right ventricular pacing. RDN was performed simultaneously with the pacemaker implantation in the HF+RDN group. A 64-unipolar basket catheter was used to perform global endocardial mapping of the left ventricle...
November 2, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/29091329/repolarization-abnormalities-unmasked-with-exercise-in-sudden-cardiac-death-survivors-with-structurally-normal-hearts
#5
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/29059485/clinical-assessment-and-comparison-of-annotation-algorithms-in-high-density-mapping-of-regular-atrial-tachycardias
#6
Jan De Pooter, Milad El Haddad, Michael Wolf, Thomas Phlips, Frederic van Heuverswyn, Liesbeth Timmers, René Tavernier, Sebastien Knecht, Yves Vandekerckhove, Mattias Duytschaever
BACKGROUND: High-density automated mapping of regular atrial tachycardias (AT) requires accurate assessment of local activation times (LAT). OBJECTIVE: To evaluate high density mapping of ATs and compare the accuracy of different automated LAT annotation algorithms. METHODS: Fifteen patients underwent AT ablation guided by the automated ConfiDENSEۛ high-density mapping module (Carto 3 v4) allowing manual reannotation (edited maps). For each AT, unedited automated maps were re-constructed offline by three algorithms: maximum unipolar slope (LATSlope ), bipolar peak (LATPeak ) and a new hybrid annotation algorithm (LATHybrid )...
October 23, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/29042091/effects-of-renal-denervation-on-coronary-flow-reserve-and-forearm-dilation-capacity-in-patients-with-treatment-resistant-hypertension-a-randomized-double-blinded-sham-controlled-clinical-trial
#7
Morten Engholm, Jannik B Bertelsen, Ole N Mathiassen, Hans E Bøtker, Henrik Vase, Christian D Peters, Jesper N Bech, Niels H Buus, Anne P Schroeder, Hans Rickers, Klavs W Hansen, Per L Poulsen, Anne Kaltoft, Kent L Christensen
BACKGROUND: Microvascular impairment is well documented in hypertension. We investigated the effect of renal sympathetic denervation (RDN) on cardiac and peripheral microvasculature in patients with treatment-resistant essential hypertension (TRH). METHODS: A randomized, single centre, double-blinded, sham-controlled clinical trial. Fifty-eight patients with TRH (ambulatory systolic BP (ASBP) ≥ 145mmHg) despite stable treatment were randomized to RDN or SHAM. RDN was performed with the unipolar Medtronic Flex catheter...
October 1, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/29038101/influence-of-intramyocardial-adipose-tissue-on-the-accuracy-of-endocardial-contact-mapping-of-the-chronic-myocardial-infarction-substrate
#8
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/28887361/technical-considerations-on-phase-mapping-for-identification-of-atrial-reentrant-activity-in-direct-and-inverse-computed-electrograms
#9
Miguel Rodrigo, Andreu M Climent, Alejandro Liberos, Francisco Fernández-Avilés, Omer Berenfeld, Felipe Atienza, Maria S Guillem
BACKGROUND: Phase mapping has become a broadly used technique to identify atrial reentrant circuits for ablative therapy guidance. This work studies the phase mapping process and how the signal nature and its filtering affect the reentrant pattern characterization in electrogram (EGM), body surface potential mapping, and electrocardiographic imaging signals. METHODS AND RESULTS: EGM, body surface potential mapping, and electrocardiographic imaging phase maps were obtained from 17 simulations of atrial fibrillation, atrial flutter, and focal atrial tachycardia...
September 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28862787/panoramic-atrial-mapping-with-basket-catheters-a-quantitative-analysis-to-optimize-practice-patient-selection-and-catheter-choice
#10
Shohreh Honarbakhsh, Richard J Schilling, Rui Providência, Gurpreet Dhillon, Vinit Sawhney, Claire A Martin, Emily Keating, Malcolm Finlay, Syed Ahsan, Anthony Chow, Mark J Earley, Ross J Hunter
INTRODUCTION: Panoramic mapping with basket catheters has been used to map atrial fibrillation (AF). However, the limited tissue contact and coverage achieved has raised concerns. METHODS AND RESULTS: Patients undergoing catheter ablation for atrial tachycardia (AT) and persistent AF were recruited. Unipolar signals were recorded with the Constellation or FIRMap catheters. The proportion and distribution of anatomical coverage by the catheters was determined and tissue contact achieved measured...
September 1, 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28798020/unipolar-endocardial-voltage-mapping-in-the-right-ventricle-optimal-cutoff-values-correcting-for-computed-tomography-derived-epicardial-fat-thickness-and-their-clinical-value-for-substrate-delineation
#11
Jeroen Venlet, Sebastiaan R D Piers, Gijsbert F L Kapel, Marta de Riva, Philippe F G Pauli, Rob J van der Geest, Katja Zeppenfeld
BACKGROUND: Low endocardial unipolar voltage (UV) at sites with normal bipolar voltage (BV) may indicate epicardial scar. Currently applied UV cutoff values are based on studies that lacked epicardial fat information. This study aimed to define endocardial UV cutoff values using computed tomography-derived fat information and to analyze their clinical value for right ventricular substrate delineation. METHODS AND RESULTS: Thirty-three patients (50±14 years; 79% men) underwent combined endocardial-epicardial right ventricular electroanatomical mapping and ablation of right ventricular scar-related ventricular tachycardia with computed tomographic image integration, including computed tomography-derived fat thickness...
August 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28730651/a-comparison-of-the-electrophysiologic-and-electroanatomic-characteristics-between-the-right-and-left-atrium-in-persistent-atrial-fibrillation-is-the-right-atrium-a-window-into-the-left
#12
Sandeep Prabhu, Aleksandr Voskoboinik, Alex J A McLellan, Kah Y Peck, Bhupesh Pathik, Chrishan J Nalliah, Geoff R Wong, Sonia M Azzopardi, Geoffrey Lee, Justin Mariani, Liang-Han Ling, Andrew J Taylor, Jonathan M Kalman, Peter M Kistler
INTRODUCTION: The right atrium (RA) is readily accessible; however, it is unclear whether changes in the RA are representative of the LA. We performed detailed biatrial electroanatomic mapping to determine the electrophysiological relationship between the atria. METHODS AND RESULTS: Consecutive patients with persistent AF underwent biatrial electroanatomical mapping with a contact force catheter acquiring points with a CF >10 g prior to ablation. Points were analyzed for tissue voltage, complex electrograms, low voltage (<0...
October 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28727202/influence-of-the-left-atrial-contact-areas-on-fixed-low-voltage-zones-during-atrial-fibrillation-and-sinus-rhythm-in-persistent-atrial-fibrillation
#13
Shiro Nakahara, Yuichi Hori, Naoki Nishiyama, Yasuo Okumura, Reiko Fukuda, Sayuki Kobayashi, Takaaki Komatsu, Yoshihiko Sakai, Isao Taguchi
BACKGROUND: Atrial low-voltage zones (LVZ) are suggested as important factors for maintaining persistent atrial fibrillation (PsAF). The relationship between LVZs and left atrial (LA) contact areas (CoAs) is still unclear. OBJECTIVE: To assess whether CoA regions were involved in atrial substrate properties maintaining PsAF. METHODS: A total of 50 patients with PsAF (36 long-lasting) were analyzed. Three representative CoA detection areas (ascending aorta-anterior-LA, descending aorta-left pulmonary vein antrum, and vertebrae-posterior-LA) were registered on the mapping geometry...
November 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28678875/evaluation-of-the-use-of-unipolar-voltage-amplitudes-for-detection-of-myocardial-scar-assessed-by-cardiac-magnetic-resonance-imaging-in-heart-failure-patients
#14
Uyên Châu Nguyên, Francesco Maffessanti, Masih Mafi-Rad, Giulio Conte, Stef Zeemering, François Regoli, Maria Luce Caputo, Antonius M W van Stipdonk, Sebastiaan C A M Bekkers, Daniel Suerder, Tiziano Moccetti, Rolf Krause, Frits W Prinzen, Kevin Vernooy, Angelo Auricchio
BACKGROUND: Validation of voltage-based scar delineation has been limited to small populations using mainly endocardial measurements. The aim of this study is to compare unipolar voltage amplitudes (UnipV) with scar on delayed enhancement cardiac magnetic resonance imaging (DE-CMR). METHODS: Heart failure patients who underwent DE-CMR and electro-anatomic mapping were included. Thirty-three endocardial mapped patients and 27 epicardial mapped patients were investigated...
2017: PloS One
https://www.readbyqxmd.com/read/28639747/the-effect-of-activation-rate-on-left-atrial-bipolar-voltage-in-patients-with-paroxysmal-atrial-fibrillation
#15
Steven E Williams, Nick Linton, Louisa O'Neill, James Harrison, John Whitaker, Rahul Mukherjee, Christopher A Rinaldi, Jaswinder Gill, Steven Niederer, Matthew Wright, Mark O'Neill
INTRODUCTION: Bipolar voltage is used during electroanatomic mapping to define abnormal myocardium, but the effect of activation rate on bipolar voltage is not known. We hypothesized that bipolar voltage may change in response to activation rate. By examining corresponding unipolar signals we sought to determine the mechanisms of such changes. METHODS AND RESULTS: LA extrastimulus mapping was performed during CS pacing in 10 patients undergoing first time paroxysmal atrial fibrillation ablation...
September 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/28553365/mini-electrodes-on-ablation-catheters-valuable-addition-or-redundant-information-insights-from-a-computational-study
#16
Stefan Pollnow, Joachim Greiner, Tobias Oesterlein, Eike M Wülfers, Axel Loewe, Olaf Dössel
Radiofrequency ablation has become a first-line approach for curative therapy of many cardiac arrhythmias. Various existing catheter designs provide high spatial resolution to identify the best spot for performing ablation and to assess lesion formation. However, creation of transmural and nonconducting ablation lesions requires usage of catheters with larger electrodes and improved thermal conductivity, leading to reduced spatial sensitivity. As trade-off, an ablation catheter with integrated mini electrodes was introduced...
2017: Computational and Mathematical Methods in Medicine
https://www.readbyqxmd.com/read/28546283/high-resolution-mapping-of-gastric-slow-wave-recovery-profiles-biophysical-model-methodology-and-demonstration-of-applications
#17
N Paskaranandavadivel, L K Cheng, P Du, J M Rogers, G O'Grady
Slow waves play a central role in coordinating gastric motor activity. High-resolution mapping of extracellular potentials from the stomach provides spatiotemporal detail on normal and dysrhythmic slow-wave patterns. All mapping studies to date have focused exclusively on tissue activation; however, the recovery phase contains vital information on repolarization heterogeneity, the excitable gap, and refractory tail interactions but has not been investigated. Here, we report a method to identify the recovery phase in slow-wave mapping data...
September 1, 2017: American Journal of Physiology. Gastrointestinal and Liver Physiology
https://www.readbyqxmd.com/read/28536891/myocardial-voltage-ratio-in-arrhythmogenic-right-ventricular-dysplasia-cardiomyopathy
#18
REVIEW
Andreas Müssigbrodt, Livio Bertagnolli, Elena Efimova, Jedrzej Kosiuk, Borislav Dinov, Kerstin Bode, Simon Kircher, Nikolaos Dagres, Michael Döring, Sergio Richter, Philipp Sommer, Daniela Husser, Andreas Bollmann, Gerhard Hindricks, Arash Arya
AIMS: This study aimed to analyze the influence of scar distribution between the endocardium and the epicardium in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). METHODS: Electroanatomical mapping data were derived from our ARVD/C registry. Myocardial voltage distribution between the endocardium and the epicardium was analyzed in 28 patients (18 men, 49.9 ± 13.0 years) with previous ventricular tachycardia (VT) ablation and complete right ventricular maps...
June 2017: Herzschrittmachertherapie & Elektrophysiologie
https://www.readbyqxmd.com/read/28525920/torsade-de-pointes-arrhythmias-arise-at-the-site-of-maximal-heterogeneity-of-repolarization-in-the-chronic-complete-atrioventricular-block-dog
#19
Albert Dunnink, Thom R G Stams, Alexandre Bossu, Veronique M F Meijborg, Jet D M Beekman, Sofieke C Wijers, Jacques M T De Bakker, Marc A Vos
Aims: The chronic complete atrioventricular block (CAVB) dog is highly sensitive for drug-induced torsade de pointes (TdP) arrhythmias. Focal mechanisms have been suggested as trigger for TdP onset; however, its exact mechanism remains unclear. In this study, detailed mapping of the ventricles was performed to assess intraventricular heterogeneity of repolarization in relation to the initiation of TdP. Methods and results: In 8 CAVB animals, 56 needles, each containing 4 electrodes, were inserted in the ventricles...
May 1, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28504840/clinical-utility-of-a-short-resting-state-mri-scan-in-differentiating-bipolar-from-unipolar-depression
#20
M Li, T Das, W Deng, Q Wang, Y Li, L Zhao, X Ma, Y Wang, H Yu, X Li, Y Meng, L Palaniyappan, T Li
OBJECTIVE: Depression in bipolar disorder (BipD) requires a therapeutic approach that is from treating unipolar major depressive disorder (UniD), but to date, no reliable methods could separate these two disorders. The aim of this study was to establish the clinical validity and utility of a non-invasive functional MRI-based method to classify BipD from UniD. METHOD: The degree of connectivity (degree centrality or DC) of every small unit (voxel) with every other unit of the brain was estimated in 22 patients with BipD and 22 age, gender, and depressive severity-matched patients with UniD and 22 healthy controls...
September 2017: Acta Psychiatrica Scandinavica
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