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Unipolar mapping

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https://www.readbyqxmd.com/read/28011584/effect-of-anisotropy-on-ventricular-vulnerability-to-unidirectional-block-and-reentry-by-single-premature-stimulation-during-normal-sinus-rhythm-in-rat-heart
#1
Stefano Rossi, Andrea Buccarello, Philip R Ershler, Robert L Lux, Sergio Callegari, Domenico Corradi, Luca Carnevali, Andrea Sgoifo, Michele Miragoli, Ezio Musso, Emilio Macchi
Single high-intensity premature stimuli when applied to the ventricles during ventricular drive of an ectopic site, as in the Winfree's "pinwheel experiment", usually induce reentry arrhythmias in the normal heart, while single low-intensity stimuli barely do. Yet, ventricular arrhythmia vulnerability during normal sinus-rhythm remains largely unexplored. With a view to define the role of anisotropy on ventricular vulnerability to unidirectional conduction block and reentry, we revisited the pinwheel experiment with reduced constraints in the in situ rat heart...
December 23, 2016: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/27932238/gender-differences-in-patients-with-arrhythmogenic-right-ventricular-dysplasia-cardiomyopathy-clinical-manifestations-electrophysiological-properties-substrate-characteristics-and-prognosis-of-radiofrequency-catheter-ablation
#2
Chin-Yu Lin, Fa-Po Chung, Yenn-Jiang Lin, Shih-Lin Chang, Li-Wei Lo, Yu-Feng Hu, Ta-Chuan Tuan, Tze-Fan Chao, Jo-Nan Liao, Yao-Ting Chang, Yun-Yu Chen, Rohit Walia, Abigail Louise D Te, Shinya Yamada, Shih-Ann Chen
BACKGROUND: Gender differences in the penetrance and clinical expression of genetic mutations have been reported in patients with arrhythmogenic right ventricular (RV) dysplasia/cardiomyopathy (ARVD/C). Our study aimed at clarifying the impact of gender on ventricular substrates and clinical outcomes after radiofrequency catheter ablation (RFCA). METHODS: Patients with ARVD/C underwent RFCA for drug-refractory ventricular arrhythmias (VAs) were consecutively enrolled...
January 15, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/27930354/simultaneous-non-invasive-epicardial-and-endocardial-mapping-in-patients-with-brugada-syndrome-new-insights-into-arrhythmia-mechanisms
#3
Boris Rudic, Maria Chaykovskaya, Alexey Tsyganov, Vitaly Kalinin, Erol Tülümen, Theano Papavassiliu, Christina Dösch, Volker Liebe, Jürgen Kuschyk, Susanne Röger, Ibrahim El-Battrawy, Ibrahim Akin, Marina Yakovleva, Elena Zaklyazminskaya, Anna Shestak, Stanislav Kim, Mikhail Chmelevsky, Martin Borggrefe
BACKGROUND: The underlying mechanisms of Brugada syndrome (BrS) are not completely understood. Recent studies provided evidence that the electrophysiological substrate, leading to electrocardiogram abnormalities and/or ventricular arrhythmias, is located in the right ventricular outflow tract (RVOT). The purpose of this study was to examine abnormalities of epicardial and endocardial local unipolar electrograms by simultaneous noninvasive mapping in patients with BrS. METHODS AND RESULTS: Local epicardial and endocardial unipolar electrograms were analyzed using a novel noninvasive epi- and endocardial electrophysiology system (NEEES) in 12 patients with BrS and 6 with right bundle branch block for comparison...
November 14, 2016: Journal of the American Heart Association
https://www.readbyqxmd.com/read/27921187/rotor-tracking-using-phase-of-electrograms-recorded-during-atrial-fibrillation
#4
Caroline H Roney, Chris D Cantwell, Norman A Qureshi, Rasheda A Chowdhury, Emmanuel Dupont, Phang Boon Lim, Edward J Vigmond, Jennifer H Tweedy, Fu Siong Ng, Nicholas S Peters
Extracellular electrograms recorded during atrial fibrillation (AF) are challenging to interpret due to the inherent beat-to-beat variability in amplitude and duration. Phase mapping represents these voltage signals in terms of relative position within the cycle, and has been widely applied to action potential and unipolar electrogram data of myocardial fibrillation. To date, however, it has not been applied to bipolar recordings, which are commonly acquired clinically. The purpose of this study is to present a novel algorithm for calculating phase from both unipolar and bipolar electrograms recorded during AF...
December 5, 2016: Annals of Biomedical Engineering
https://www.readbyqxmd.com/read/27906655/methodology-considerations-in-phase-mapping-of-human-cardiac-arrhythmias
#5
Ramya Vijayakumar, Sunil K Vasireddi, Phillip S Cuculich, Mitchell N Faddis, Yoram Rudy
BACKGROUND: Phase analysis of cardiac arrhythmias, particularly atrial fibrillation, has gained interest because of the ability to detect organized stable drivers (rotors) and target them for therapy. However, the lack of methodology details in publications on the topic has resulted in ongoing debate over the phase mapping technique. By comparing phase maps and activation maps, we examined advantages and limitations of phase mapping. METHODS AND RESULTS: Seven subjects were enrolled...
November 2016: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/27870970/panoramic-characterization-of-endocardial-left-atrial-activation-during-human-persistent-af-insights-from-non-contact-mapping
#6
Geoffrey Lee, Alex J A McLellan, Ross J Hunter, Matthew J Lovell, Malcolm Finlay, Waqas Ullah, Mehul B Dhinoja, Simon Sporton, Mark J Earley, Richard J Schilling
BACKGROUND: The relative importance of focal drivers, multiple wavelets, rotors and endocardial-epicardial circuits in the maintenance of persistent AF remains unclear. Our objective was to characterize AF wavefront (WF) dynamics during persistent AF. METHODS: The Ensite 3000 (St Jude Medical) non-contact mapping system was used to map the LA of 15 patients with persistent AF. Wavefronts were classified into planar WFs, rotors or focal WFs. For each new WF the site of origin, the unipolar electrogram, and propagation patterns were determined...
February 1, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/27766704/treatment-of-recurrent-nonparoxysmal-atrial-fibrillation-using-focal-impulse-and-rotor-mapping-firm-guided-rotor-ablation-early-recurrence-and-long-term-outcomes
#7
Stefan Georg Spitzer, László Károlyi, Carola Rämmler, Frank Scharfe, Thomas Weinmann, Mirko Zieschank, Anke Langbein
INTRODUCTION: A patient-tailored ablation approach focused on the elimination of both pulmonary vein triggers as well as substrate drivers may result in favorable outcomes in recurrent persistent AF patients. OBJECTIVE: We evaluated the long-term outcomes of rotor ablation combined with conventional pulmonary vein isolation (PVI) in patients with recurrent nonparoxysmal AF. METHODS: Fifty-eight consecutive patients underwent FIRM-guided rotor ablation followed by conventional PVI for the treatment of recurrent nonparoxysmal AF...
January 2017: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/27737802/cardiac-activation-repolarization-patterns-and-ion-channel-expression-mapping-in-intact-isolated-normal-human-hearts
#8
Tobias Opthof, Carol Ann Remme, Esther Jorge, Francisco Noriega, Rob F Wiegerinck, Arlin Tasiam, Leander Beekman, Jesus Alvarez-Garcia, Cristian Munoz-Guijosa, Ruben Coronel, Juan Cinca
BACKGROUND: The repolarization pattern of the human heart is unknown. OBJECTIVE: The purpose of this study was to perform a multisite analysis of the activation-repolarization patterns and mRNA expression patterns of ion channel subunits in isolated human hearts. METHODS: Hearts from 3 donors without reported cardiac disease were Langendorff perfused with the patient's own blood. A standard ECG was obtained before explantation. Up to 92 unipolar electrograms from 24 transmural needles were obtained during right atrial pacing...
October 11, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/27663606/a-novel-approach-for-left-ventricular-lead-placement-in-cardiac-resynchronization-therapy-intraprocedural-integration-of-coronary-venous-electroanatomic-mapping-with-delayed-enhancement-cardiac-magnetic-resonance-imaging
#9
Uyên Châu Nguyên, Masih Mafi-Rad, Jean-Paul Aben, Martijn W Smulders, Elien B Engels, Antonius M W van Stipdonk, Justin G L M Luermans, Sebastiaan C A M Bekkers, Frits W Prinzen, Kevin Vernooy
BACKGROUND: Placing the left ventricular (LV) lead at a site of late electrical activation remote from scar is desired to improve cardiac resynchronization therapy (CRT) response. OBJECTIVE: The purpose of this study was to integrate coronary venous electroanatomic mapping (EAM) with delayed enhancement cardiac magnetic resonance (DE-CMR) enabling LV lead guidance to the latest activated vein remote from scar. METHODS: Eighteen CRT candidates with focal scar on DE-CMR were prospectively included...
January 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/27547135/association-between-high-endocardial-unipolar-voltage-and-improved-left-ventricular-function-in-patients-with-ischemic-cardiomyopathy
#10
Ki Park, Dejian Lai, Eileen M Handberg, Lem Moyé, Emerson C Perin, Carl J Pepine, R David Anderson
We know that endocardial mapping reports left ventricular electrical activity (voltage) and that these data can predict outcomes in patients undergoing traditional revascularization. Because the mapping data from experimental models have also been linked with myocardial viability, we hypothesized an association between increased unipolar voltage in patients undergoing intramyocardial injections and their subsequent improvement in left ventricular performance. For this exploratory analysis, we evaluated 86 patients with left ventricular dysfunction, heart-failure symptoms, possible angina, and no revascularization options, who were undergoing endocardial mapping...
August 2016: Texas Heart Institute Journal
https://www.readbyqxmd.com/read/27516464/directional-influences-of-ventricular-activation-on-myocardial-scar-characterization-voltage-mapping-with-multiple-wavefronts-during-ventricular-tachycardia-ablation
#11
Roderick Tung, Mark E Josephson, Jason S Bradfield, Kalyanam Shivkumar
BACKGROUND: The effects of varying the wavefront of activation on ventricular scar characterization has not been systematically assessed. METHODS AND RESULTS: Patients referred for ablation of scar-related ventricular tachycardia underwent voltage maps during a minimum of 2 wavefronts of activation. The bipolar and unipolar low-voltage areas were compared, and direct electrogram analysis was performed in regions where discrepancies were seen. Concordance between wavefronts was measured by calculating percentage of overlap between maps...
August 2016: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/27460068/localization-and-identification-of-crustacean-hyperglycemic-hormone-producing-neurosecretory-cells-in-the-eyestalk-of-blue-swimmer-crab-portunus-pelagicus
#12
Saravanan Rajendiran, Sugumar Vasudevan
This study intensely focuses on to the localization and identification of crustacean hyperglycemic hormone (CHH) producing neurosecretory cells in the eyestalk of the blue swimmer crab Portunus pelagicus. Anti-Carcinus maenas-CHH was used to identify the location of CHH neurosecretory cells by immunohistochemistry. Ten pairs of eyestalks were collected from intact adult intermoult female crab and fixed in Bouin's fixative. Eyestalks were serially sectioned and stained with chrome-hematoxylin-phloxine stain...
July 27, 2016: Microscopy Research and Technique
https://www.readbyqxmd.com/read/27448338/spatially-coherent-activation-maps-for-electrocardiographic-imaging
#13
Josselin Duchateau, Mark Potse, Remi Dubois
OBJECTIVE: Cardiac mapping is an important diagnostic step in cardiac electrophysiology. One of its purposes is to generate a map of the depolarization sequence. This map is constructed in clinical routine either by directly analyzing cardiac electrograms (EGM) recorded invasively or an estimate of these EGMs obtained by a non-invasive technique. Activation maps based on noninvasively estimated EGMs often show artefactual jumps in activation times. To overcome this problem we present a new method to construct the activation maps from reconstructed unipolar EGMs...
July 19, 2016: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/27440005/high-resolution-mapping-of-postinfarction-reentrant-ventricular-tachycardia-electrophysiological-characterization-of-the-circuit
#14
Elad Anter, Cory M Tschabrunn, Alfred E Buxton, Mark E Josephson
BACKGROUND: In vivo description of ventricular tachycardia (VT) circuits is limited by insufficient spatiotemporal resolution. We used a novel high-resolution mapping technology to characterize the electrophysiological properties of the postinfarction reentrant VT circuit. METHODS: In 15 swine, myocardial infarction was induced by left anterior descending artery balloon occlusion. Animals were studied 6 to 8 weeks after myocardial infarction. Activation mapping of VTs was performed by using the Rhythmia mapping system...
July 26, 2016: Circulation
https://www.readbyqxmd.com/read/27439651/experimental-validation-of-noninvasive-epicardial-and-endocardial-activation-imaging
#15
Peter Oosterhoff, Veronique M F Meijborg, Peter M van Dam, Pascal F H M van Dessel, Charly N W Belterman, Geert J Streekstra, Jacques M T de Bakker, Ruben Coronel, Thom F Oostendorp
BACKGROUND: Noninvasive imaging of cardiac activation before ablation of the arrhythmogenic substrate can reduce electrophysiological procedure duration and help choosing between an endocardial or epicardial approach. A noninvasive imaging technique was evaluated that estimates both endocardial and epicardial activation from body surface potential maps. We performed a study in isolated and in situ pig hearts, estimating activation from body surface potential maps during sinus rhythm and localizing endocardial and epicardial stimulation sites...
August 2016: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/27392944/scar-voltage-threshold-determination-using-ex-vivo-magnetic-resonance-imaging-integration-in-a-porcine-infarct-model-influence-of-interelectrode-distances-and-three-dimensional-spatial-effects-of-scar
#16
Roderick Tung, Steve Kim, Daigo Yagishita, Marmar Vaseghi, Daniel B Ennis, Sarah Ouadah, Olujimi A Ajijola, Jason S Bradfield, Srijoy Mahapatra, Paul Finn, Kalyanam Shivkumar
BACKGROUND: Studies analyzing optimal voltage thresholds for scar detection with electroanatomic mapping frequently lack a gold standard for comparison. OBJECTIVE: The purpose of this study was to use a porcine infarct model with ex vivo magnetic resonance imaging (MRI) integration to characterize the relationship between interelectrode spacing and bipolar voltage thresholds and examine the influence of 3-dimensional scar on unipolar voltages. METHODS: Thirty-two combined endocardial-epicardial electroanatomic maps were created in 8 postinfarct porcine subjects (bipolar 2-mm, 5-mm, and 8-mm interelectrode spacing and unipolar) for comparison with ex vivo MRI...
October 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/27207812/noninvasive-epicardial-and-endocardial-mapping-of-premature-ventricular-contractions
#17
Erik Wissner, Amiran Revishvili, Andreas Metzner, Alexey Tsyganov, Vitaly Kalinin, Christine Lemes, Ardan M Saguner, Tilman Maurer, Sebastian Deiss, Oleg Sopov, Eugene Labarkava, Mikhail Chmelevsky, Karl-Heinz Kuck
AIMS: The aim of the present study was to estimate the accuracy of a novel non-invasive epicardial and endocardial electrophysiology system (NEEES) for mapping ectopic ventricular depolarizations. METHODS AND RESULTS: The study enrolled 20 patients with monomorphic premature ventricular contractions (PVCs) or ventricular tachycardia (VT). All patients underwent pre-procedural computed tomography or magnetic resonance imaging of the heart and torso. Radiographic data were semi-automatically processed by the NEEES to reconstruct a realistic 3D model of the heart and torso...
May 20, 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27198720/cux2-serves-as-a-novel-lineage-marker-of-granule-cell-layer-neurons-from-the-rhombic-lip-in-mouse-and-chick-embryos
#18
Emily Capaldo, Angelo Iulianella
BACKGROUND: The rhombic lip (RL), a germinal zone in the developing hindbrain, gives rise to all of the excitatory neurons of the cerebellum. It is presently unclear what factors distinguish between RL progenitor pools and play a role in differentiating the multiple cell types that arise from this region. The transcription factor Cux2 has been shown to play important roles in proliferation and differentiation of distinct neuronal populations during embryogenesis, but its role in cerebellar fate restriction is unknown...
August 2016: Developmental Dynamics: An Official Publication of the American Association of Anatomists
https://www.readbyqxmd.com/read/27197804/electrophysiologic-scar-substrate-in-relation-to-vt-noninvasive-high-resolution-mapping-and-risk-assessment-with-ecgi
#19
Junjie Zhang, Daniel H Cooper, Kavit A Desouza, Phillip S Cuculich, Pamela K Woodard, Timothy W Smith, Yoram Rudy
BACKGROUND: Ischemic cardiomyopathy (ICM) can provide the substrate for ventricular tachycardia (VT). OBJECTIVE: To map noninvasively with high resolution the electrophysiologic (EP) scar substrate, identify its relationship to reentry circuits during VT, and stratify VT risk in ICM patients. METHODS: Noninvasive high-resolution epicardial mapping with electrocardiographic imaging (ECGI) was performed in 32 ICM patients (17 with clinical VT, 15 without VT)...
August 2016: Pacing and Clinical Electrophysiology: PACE
https://www.readbyqxmd.com/read/27153879/relevance-of-conduction-disorders-in-bachmann-s-bundle-during-sinus-rhythm-in-humans
#20
Christophe P Teuwen, Ameeta Yaksh, Eva A H Lanters, Charles Kik, Lisette J M E van der Does, Paul Knops, Yannick J H J Taverne, Pieter C van de Woestijne, Frans B S Oei, Jos A Bekkers, Ad J J C Bogers, Maurits A Allessie, Natasja M S de Groot
BACKGROUND: Bachmann's bundle (BB) is considered to be the main route of interatrial conduction and to play a role in development of atrial fibrillation (AF). The goals of this study are to characterize the presence of conduction disorders in BB during sinus rhythm and to study their relation with AF. METHODS AND RESULTS: High-resolution epicardial mapping (192 unipolar electrodes, interelectrode distance: 2 mm) of sinus rhythm was performed in 185 patients during coronary artery bypass surgery of whom 13 had a history of paroxysmal AF...
May 2016: Circulation. Arrhythmia and Electrophysiology
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