keyword
MENU ▼
Read by QxMD icon Read
search

Voltage Mapping

keyword
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
#1
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/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
#2
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
#3
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/29129203/naadp-evoked-ca-2-signals-through-two-pore-channel-1-require-arginine-residues-in-the-first-s4-s5-linker
#4
Sandip Patel, Dev Churamani, Eugen Brailoiu
Two-pore channels (TPCs) are two-domain members of the voltage-gated ion channel superfamily that localize to acidic organelles. Their mechanism of activation (ligands such as NAADP/PI(3,5)P2 versus voltage) and ion selectivity (Ca(2+) versus Na(+)) is debated. Here we report that a cluster of arginine residues in the first domain required for selective voltage-gating of TPC1 map not to the voltage-sensing fourth transmembrane region (S4) but to a cytosolic downstream region (S4-S5 linker). These residues are conserved between TPC isoforms suggesting a generic role in TPC activation...
December 2017: Cell Calcium
https://www.readbyqxmd.com/read/29112377/transparent-perovskite-light-emitting-touch-responsive-device
#5
Shu-Yu Chou, Rujun Ma, Yunfei Li, Fangchao Zhao, Kwing Tong, Zhibin Yu, Qibing Pei
A light-emitting touch-responsive device (LETD) for instantaneous visualization of pressure mapping is reported. The LETD integrates an organometal halide perovskite polymer composite emissive layer and a flexible silver nanowire polyurethane composite transparent electrode. The composite emissive layer contains methylammonium lead bromide nanocrystals uniformly dispersed in a poly(ethylene oxide) (PEO) matrix and emits an intense green luminescence that peaks at 529 nm. The PEO matrix promotes the formation of small perovskite grains (∼20 nm) and a pinhole-free composite film with surface roughness of only 2...
November 7, 2017: ACS Nano
https://www.readbyqxmd.com/read/29104543/simultaneous-quantification-of-spatially-discordant-alternans-in-voltage-and-intracellular-calcium-in-langendorff-perfused-rabbit-hearts-and-inconsistencies-with-models-of-cardiac-action-potentials-and-ca-transients
#6
Ilija Uzelac, Yanyan C Ji, Daniel Hornung, Johannes Schröder-Scheteling, Stefan Luther, Richard A Gray, Elizabeth M Cherry, Flavio H Fenton
Rationale: Discordant alternans, a phenomenon in which the action potential duration (APDs) and/or intracellular calcium transient durations (CaDs) in different spatial regions of cardiac tissue are out of phase, present a dynamical instability for complex spatial dispersion that can be associated with long-QT syndrome (LQTS) and the initiation of reentrant arrhythmias. Because the use of numerical simulations to investigate arrhythmic effects, such as acquired LQTS by drugs is beginning to be studied by the FDA, it is crucial to validate mathematical models that may be used during this process...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29100747/box-isolation-of-fibrotic-areas-a-substrate-modification-approach-in-atrial-fibrillation-patients
#7
REVIEW
Fabian Moser, Doreen Schreiber, Andreas Rieger, Monica Trofin, Christian Pönisch, Hans Kottkamp
In the last years, atrial fibrosis was shown to be an independent predictor of procedural failure in patients with paroxysmal and persistent atrial fibrillation. Ablation strategies have been developed to improve the outcome of catheter ablation by targeting detected areas of fibrosis, based either on endocardial voltage mapping or cardiac magnetic resonance. Box isolation of fibrotic areas (BIFA) is a new and promising patient-tailored ablation strategy for atrial fibrillation patients targeting substantial fibrotic areas by circumferential isolation of left atrial fibrosis...
October 31, 2017: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
https://www.readbyqxmd.com/read/29094408/-electro-typing-on-a-carbon-nanoparticles-filled-polymeric-film-using-conducting-atomic-force-microscopy
#8
Sumita Goswami, Suman Nandy, Arghya Narayan Banerjee, Asal Kiazadeh, Gowra Raghupathy Dillip, Joana V Pinto, Sang Woo Joo, Rodrigo Martins, Elvira Fortunato
Next-generation electrical nanoimprinting of a polymeric data sheet based on charge trapping phenomena is reported here. Carbon nanoparticles (CNPs) (waste carbon product) are deployed into a polymeric matrix (polyaniline) (PANI) as a charge trapping layer. The data are recorded on the CNPs-filled polyaniline device layer by "electro-typing" under a voltage pulse (VET , from ±1 to ±7 V), which is applied to the device layer through a localized charge-injection method. The core idea of this device is to make an electrical image through the charge trapping mechanism, which can be "read" further by the subsequent electrical mapping...
November 2, 2017: Advanced Materials
https://www.readbyqxmd.com/read/29089463/increased-serum-lysyl-oxidase-like-2-levels-correlate-with-the-degree-of-left-atrial-fibrosis-in-patients-with-atrial-fibrillation
#9
Yingming Zhao, Kangting Tang, Xu Tianbao, Junhong Wang, Jin Yang, Dianfu Li
Atrial fibrillation (AF) progression is generally accompanied by increased atrial fibrosis and atrial structural remodeling. Lysyl oxidase-like 2 (LOXL2) is known to play an important role in many fibrotic conditions, including cardiac fibrosis. This study aimed to explore the relationship between serum LOXL2 levels and AF. Fifty-four AF patients and 32 control subjects were enrolled in the study. High-density three-dimensional electroanatomic mapping was performed, and mean bipolar voltage was assessed in AF patients...
October 31, 2017: Bioscience Reports
https://www.readbyqxmd.com/read/29081422/neural-activation-patterns-and-connectivity-in-visual-attention-during-number-and-non-number-processing-an-erp-study-using-the-ishihara-pseudoisochromatic-plates
#10
Faraj Al-Marri, Faruque Reza, Tahamina Begum, Wan Hazabbah Wan Hitam, Goh Khean Jin, Jing Xiang
Visual cognitive function is important to build up executive function in daily life. Perception of visual Number form (e.g., Arabic digit) and numerosity (magnitude of the Number) is of interest to cognitive neuroscientists. Neural correlates and the functional measurement of Number representations are complex occurrences when their semantic categories are assimilated with other concepts of shape and colour. Colour perception can be processed further to modulate visual cognition. The Ishihara pseudoisochromatic plates are one of the best and most common screening tools for basic red-green colour vision testing...
October 25, 2017: Journal of Integrative Neuroscience
https://www.readbyqxmd.com/read/29081399/re-visiting-anatomical-macroreentrant-tachycardia-after-atrial-fibrillation-ablation-using-ultra-high-resolution-mapping-implications-for-ablation
#11
Masateru Takigawa, Nicolas Derval, Antonio Frontera, Ruairidh Martin, Seigo Yamashita, Ghassen Cheniti, Konstantinos Vlachos, Nathaniel Thompson, Takeshi Kitamura, Michel Wolf, Gregoire Massoullie, Clair Martin, Nora Al-Jefairi, Sana Amraoui, Josselin Duchateau, Nicolas Klotz, Thomas Pambrun, Arnaud Denis, Frederic Sacher, Hubert Cochet, Hocini Meleze, Michel Haissaguierre, Pierre Jais
BACKGROUND: Anatomical macroreentrant atrial tachycardias (MATs) are conventionally reported to depend on the cavotricuspid isthmus (CTI), the mitral isthmus (MI), or the left atrial roof, and are commonly seen following catheter ablation (CA) for atrial fibrillation (AF). OBJECTIVES: To define the precise circuits of anatomical MAT with ultra-high resolution mapping. METHODS: In 57 patients (mean age, 62 years; 10 female) who developed at least one anatomical MAT, we analyzed 88 MAT circuits including 16 peri-tricuspid, 42 peri-mitral, and 30 roof-dependent circuits, using high-density mapping and entrainment...
October 25, 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/29075666/a-drug-pocket-at-the-lipid-bilayer-potassium-channel-interface
#12
Nina E Ottosson, Malin Silverå Ejneby, Xiongyu Wu, Samira Yazdi, Peter Konradsson, Erik Lindahl, Fredrik Elinder
Many pharmaceutical drugs against neurological and cardiovascular disorders exert their therapeutic effects by binding to specific sites on voltage-gated ion channels of neurons or cardiomyocytes. To date, all molecules targeting known ion channel sites bind to protein pockets that are mainly surrounded by water. We describe a lipid-protein drug-binding pocket of a potassium channel. We synthesized and electrophysiologically tested 125 derivatives, analogs, and related compounds to dehydroabietic acid. Functional data in combination with docking and molecular dynamics simulations mapped a binding site for small-molecule compounds at the interface between the lipid bilayer and the transmembrane segments S3 and S4 of the voltage-sensor domain...
October 2017: Science Advances
https://www.readbyqxmd.com/read/29072796/atrial-tachycardias-cause-or-effect-with-ablation-of-persistent-atrial-fibrillation
#13
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/29059057/lateral-response-heterogeneity-of-bragg-peak-ionization-chambers-for-narrow-beam-photon-and-proton-dosimetry
#14
Peter Kuess, Till Tobias Böhlen, Wolfgang Lechner, Alessio Elia, Dietmar Georg, Hugo Palmans
Large area ionization chambers (LAICs) can be used to measure output factors of narrow beams. Dose area product measurements are proposed an alternative to central-axis point-dose measurements. Using such detectors requires detailed information on the uniformity of the response along the sensitive area. Eight LAICs were investigated in this study: four of type PTW-34070 (LAICThick) and four of type PTW-34080 (LAICThin). Measurements were performed in an X-ray unit using peak voltages of 100-200 kVp and a collimated beam of 3...
October 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29058793/photovoltaic-pyroelectric-coupled-effect-induced-electricity-for-self-powered-photodetector-system
#15
Nan Ma, Kewei Zhang, Ya Yang
Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7-4 eV) suffer from low power conversion efficiency of less than 0.5% due to absorbing only 8-20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near-UV irradiations. Here, a ferroelectric BaTiO3 film-based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled...
October 23, 2017: Advanced Materials
https://www.readbyqxmd.com/read/29058201/building-atomic-models-of-the-ion-channels-based-on-low-resolution-electron-microscopy-maps-and-homology-modeling
#16
Valery Novoseletsky, Olfat A Malak, Gildas Loussouarn, Olga S Sokolova
Voltage-gated potassium channels play pivotal roles in excitable and non-excitable cells. For many decades, structural properties and molecular mechanisms of these channels were inferred from functional observations. At the turn of the twenty-first century, structural biology revealed major aspects in the structural basis of ion channel organization, permeation, and gating. Among the available tools, homology modeling associated with low resolution microscopy helps in delineating the different structural elements of voltage-gated channels...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29050870/brugada-syndrome-is-associated-with-scar-and-endocardial-involvement-insights-from-high-density-mapping-with-the-rhythmia%C3%A2-mapping-system
#17
Rui Providência, Pedro Carmo, Francisco Moscoso Costa, Diogo Cavaco, Francisco Morgado, Mauricio Scanavacca, Pedro Adragão
The authors report the first catheter ablation of Brugada syndrome in the literature using the Rhythmia™ mapping system. Learning points include: (1) low voltage areas can be documented while mapping in some individuals, suggesting that Brugada syndrome may not be a pure ion channel disorder; (2) typical long fractionated potentials can also be identified in the endocardium, supporting the need to map the endocardium in all Brugada patients requiring ablation; (3) disappearance of the typical coved pattern following ablation does not necessarily predict cure, as the patient we present experienced ventricular fibrillation recurrence a few months later...
October 2017: Portuguese Journal of Cardiology: An Official Journal of the Portuguese Society of Cardiology
https://www.readbyqxmd.com/read/29038107/law-of-spatial-averaging-during-endocardial-voltage-mapping-you-can-t-trim-out-the-fat
#18
EDITORIAL
Andrew D Beaser, Roderick Tung
No abstract text is available yet for this article.
October 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/29038101/influence-of-intramyocardial-adipose-tissue-on-the-accuracy-of-endocardial-contact-mapping-of-the-chronic-myocardial-infarction-substrate
#19
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/29021859/the-electrical-circuit-of-a-hemodynamically-unstable-and-recurrent-ventricular-tachycardia-diagnosed-in-35%C3%A2-s-with-the-rhythmia-mapping-system
#20
Masateru Takigawa, Antonio Frontera, Nathaniel Thompson, Stefano Capellino, Pierre Jais, Frederic Sacher
Herein, we report a 47-year-old woman with ischemic cardiomyopathy who underwent ablation therapy due to an electrical storm without any triggers. The voltage mapping in sinus rhythm with the Rhythmia system and Orion catheter displayed several LAVAs in and around the anteroapical scar area. Although the patient did not tolerate the induced clinical ventricular tachycardia, which was reproductively induced, 35-second-mapping in the scar zone with the Orion catheter demonstrated the VT circuit with the critical isthmus...
October 2017: Journal of Arrhythmia
keyword
keyword
36641
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"