The Experts below are selected from a list of 12978 Experts worldwide ranked by ideXlab platform
Shlomo Benhaim - One of the best experts on this subject based on the ideXlab platform.
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high resolution real time and nonfluoroscopic 3 dimensional Cardiac imaging and catheter navigation in humans using a novel dielectric based system
Heart Rhythm, 2019Co-Authors: Alexander Romanov, Eli Dichterman, Yitzhack Schwartz, Zalman Ibragimov, Yehonatan Bendavid, Haim Rodriguez, Evgeny Pokushalov, Usman Siddiqui, Andrew O Kadlec, Shlomo BenhaimAbstract:Background Catheter navigation and 3-dimensional (3D) Cardiac Mapping are essential components of minimally invasive electrophysiological procedures. Objective The purpose of this study was to develop a novel 3D Mapping system (KODEX - EPD, EPD Solutions, Best, The Netherlands) that measures changing electric field gradients induced on intraCardiac electrodes to enable catheter localization and real-time 3D Cardiac Mapping. Methods We first validated the accuracy of the system's measurement and localization capabilities by comparing known and KODEX - EPD–measured distances and locations at 12 anatomical landmarks in both the atria and ventricles of 4 swine. Next, in vivo images of 3D porcine Cardiac anatomy generated by KODEX - EPD and widely used CARTO 3 system (Biosense Webster, Inc., Diamond Bar, CA) were compared with gold standard computed tomography images acquired from the same animals. Finally, 3D maps of atrial anatomy were created for 22 patients with paroxysmal atrial fibrillation (Dielectric Unravelling of Radiofrequency ABLation Effectiveness trial). Results First, the mean error between known and measured distances was 1.08 ± 0.11 mm (P Conclusion The KODEX - EPD system is a novel 3D Mapping system that accurately detects catheter location and can generate high-resolution images without the need for preacquired imaging, specialty catheters, or a point-by-point Mapping procedure.
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a novel method for nonfluoroscopic catheter based electroanatomical Mapping of the heart in vitro and in vivo accuracy results
Circulation, 1997Co-Authors: Lior Gepstein, Gal Hayam, Shlomo BenhaimAbstract:Background Cardiac Mapping is essential for understanding the mechanisms of arrhythmias and for directing curative procedures. A major limitation of the current methods is the inability to accurately relate local electrograms to their spatial orientation. The objective of this study was to present and test the accuracy of a new method for nonfluoroscopic, catheter-based, endocardial Mapping. Methods and Results The method is based on using a new locatable catheter connected to an endocardial Mapping and navigating system. The system uses magnetic technology to accurately determine the location and orientation of the catheter and simultaneously records the local electrogram from its tip. By sampling a plurality of endocardial sites, the system reconstructs the three-dimensional geometry of the chamber, with the electrophysiological information color-coded and superimposed on the anatomy. The accuracy of the system was tested in both in vitro and in vivo studies and was found to be highly reproducible (SD, ...
Jeff Schweitzer - One of the best experts on this subject based on the ideXlab platform.
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feasibility and validation of registration of three dimensional left atrial models derived from computed tomography with a noncontact Cardiac Mapping system
Heart Rhythm, 2005Co-Authors: Jasbir Sra, David Krum, John Hare, Darin R Okerlund, Helen Thompson, Melissa Vass, Jeff Schweitzer, Eric N Olson, Dennis W Foley, Masood AkhtarAbstract:Objectives The purpose of this study was to determine the feasibility and assess the validity of registering three-dimensional (3D) models from computed tomographic (CT) images using a Cardiac Mapping system. Background Registration of 3D anatomic models with an interventional system could help identify and navigate Mapping and ablation catheters over a complex structure such as the left atrium (LA). Methods ECG-gated, contrast-enhanced Cardiac CT imaging was performed in 14 patients with atrial fibrillation. Segmentation was used to create 3D models of the LA. The 3D models were registered with the Mapping system using a series of fiducial points. Registration was accomplished retrospectively in the first 10 patients, and catheter navigation was visualized from recorded data. In the final four patients, registration was accomplished in real time during electrophysiologic study. The Mapping catheter position, as it was navigated inside the LA, was applied to the registered model in real time. For the validation study, temporary pacing leads were implanted in the LA of 10 dogs. Following this, CT scanning, segmentation, LA model importation, and registration was described previously. After registration, a Mapping catheter was positioned at the site of each buried lead according to the registered model with no fluoroscopic guidance. A radiofrequency lesion was created at this location, and the dog was sacrificed, the heart removed and stained, and the distance between the buried lead and the lesion measured. Results During the feasibility study, the location of the catheter in the registered model correlated with fluoroscopy, angiography, and intraCardiac electrograms. LA endocardial potentials during sinus rhythm and any premature atrial contractions also were successfully delineated over the registered models. In the validation study, the mean target registration error was 2.0 ± 3.6 mm. Conclusions Registration of CT-derived 3D models of the LA using a Cardiac Mapping system is feasible and accurate.
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validation of a new noncontact catheter system for electroanatomic Mapping of left ventricular endocardium
Circulation, 1999Co-Authors: Charles C Gornick, Stuart W Adler, Brian D Pederson, John A Hauck, Jeffrey Robert Budd, Jeff SchweitzerAbstract:Background—Improvements in Cardiac Mapping are required to advance our understanding and treatment of arrhythmias. This study validated a new noncontact multielectrode array catheter and accompanying analysis system to provide electroanatomic Mapping of the entire left ventricular (LV) endocardium during a single beat. Methods and Results—A 9F 64-electrode balloon array catheter with an inflated size of 1.8×4.6 cm was used to simultaneously record electrical potentials generated by the heart and locate a standard electrophysiology (EP) catheter within the same chamber. By use of the recorded location of the EP-catheter tip, LV geometry was determined. Array potentials served as inputs to a high-order boundary-element method to produce 3360 potential points on the endocardial surface translatable into electrograms or color-coded activation maps. Three methods of validation were used: (1) driven electrodes in an in vitro tank were located; (2) waveforms generated from the array catheter were compared with c...
R Nadeau - One of the best experts on this subject based on the ideXlab platform.
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three distinct patterns of ventricular activation in infarcted human hearts an intraoperative Cardiac Mapping study during sinus rhythm
Circulation, 1995Co-Authors: Robert Hatala, P Savard, Gaetan Tremblay, Pierre Page, Rene Cardinal, Franck Molin, R NadeauAbstract:Background Comprehensive data based on single-beat analysis of the ventricular activation sequence during sinus rhythm in infarcted hearts are currently not available. It was the aim of our study (1) to measure and analyze these activation sequences on the epicardial surface of the right and left ventricles and on the left ventricular endocardial surface, and (2) to correlate specific activation patterns with the surface ECG. Methods and Results Isochronal maps were computed from 127 endocardial and epicardial unipolar electrograms recorded simultaneously during sinus rhythm in 45 post–myocardial infarction patients operated on for recurrent ventricular tachycardia (age, 57±10 years [mean±SD], left ventricular ejection fraction, 29±9%). Patients with bundle-branch block, but not with intraventricular conduction defects, were excluded. Data such as the timing of initial and terminal activation, the number of breakthroughs, the total activation time, and the number of ventricular segments without activation...
Leo K. Cheng - One of the best experts on this subject based on the ideXlab platform.
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high resolution electrical Mapping of porcine gastric slow wave propagation from the mucosal surface
Neurogastroenterology and Motility, 2017Co-Authors: Timothy R Angeli, Peng Du, Niranchan Paskaranandavadivel, Shameer Sathar, Samuel J Asirvatham, Leo K. Cheng, Gianrico Farrugia, John A Windsor, A HallAbstract:BACKGROUND: Gastric motility is coordinated by bioelectrical slow waves, and gastric dysrhythmias are reported in motility disorders. High-resolution (HR) Mapping has advanced the accurate assessment of gastric dysrhythmias, offering promise as a diagnostic technique. However, HR Mapping has been restricted to invasive surgical serosal access. This study investigates the feasibility of HR Mapping from the gastric mucosal surface. METHODS: Experiments were conducted in vivo in 14 weaner pigs. Reference serosal recordings were performed with flexible-printed-circuit (FPC) arrays (128-192 electrodes). Mucosal recordings were performed by two methods: (i) FPC array aligned directly opposite the serosal array, and (ii) Cardiac Mapping catheter modified for gastric mucosal recordings. Slow-wave propagation and morphology characteristics were quantified and compared between simultaneous serosal and mucosal recordings. KEY RESULTS: Slow-wave activity was consistently recorded from the mucosal surface from both electrode arrays. Mucosally recorded slow-wave propagation was consistent with reference serosal activation pattern, frequency (P≥.3), and velocity (P≥.4). However, mucosally recorded slow-wave morphology exhibited reduced amplitude (65-72% reduced, P<.001) and wider downstroke width (18-31% wider, P≤.02), compared to serosal data. Dysrhythmias were successfully mapped and classified from the mucosal surface, accorded with serosal data, and were consistent with known dysrhythmic mechanisms in the porcine model. CONCLUSIONS & INFERENCES: High-resolution gastric electrical Mapping was achieved from the mucosal surface, and demonstrated consistent propagation characteristics with serosal data. However, mucosal signal morphology was attenuated, demonstrating necessity for optimized electrode designs and analytical algorithms. This study demonstrates feasibility of endoscopic HR Mapping, providing a foundation for advancement of minimally invasive spatiotemporal gastric Mapping as a clinical and scientific tool.
Tamer S Fahmy - One of the best experts on this subject based on the ideXlab platform.
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integration of positron emission tomography computed tomography with electroanatomical Mapping a novel approach for ablation of scar related ventricular tachycardia
Heart Rhythm, 2008Co-Authors: Tamer S Fahmy, Oussama Wazni, Wael A Jaber, Vivek Walimbe, Luigi Di Biase, Claude S Elayi, Frank P Difilippo, Ron YoungAbstract:Background Despite the recent advances in Cardiac Mapping, ablation of scar-related ventricular tachycardia (VT) still remains a clinical challenge. A detailed electroanatomical map is a prerequisite for accurate localization and ablation of the VT substrate. Objective The purpose of this study was to evaluate the feasibility and accuracy of integrating the positron emission tomography (PET)/computed tomography (CT) with the electroanatomical map and compare the accuracy of the voltage-based scar with the biological scar. Methods Patients undergoing radiofrequency ablation (n = 19) for scar-related VT were enrolled. CT angiography and PET scans were performed for all patients. Tomographic and volumetric data from both images were processed and coregistered using internally designed software. That image was segmented in an electrophysiology Mapping system and registered to the electroanatomical map. Eight different thresholds were applied on the voltage map to define the scar. The surface areas of the biological and electrical dense scars at different thresholds were measured and compared. Results The PET/CT image was well integrated with the electroanatomical map with a mean surface registration error of 5.1 ± 2.1 mm. Of the eight different thresholds defining the scar, the surface area of the scar at a threshold of 0.9 mV (68.6 ± 49.2 cm 2 ) correlated best with the surface area of the PET-based scar (70.4 ± 49.3 cm 2 ) and had the least total area error (4.8 ± 1.8 cm 2 ) compared with the 0.5 threshold (29.7 ± 23.9 cm 2 ). Conclusion Integrating PET/CT with the electroanatomical map is feasible and accurate. Based on the biological scar, readjustment of the voltage scar threshold to 0.9 mV is suggested. In view of the better accuracy of PET/CT in defining scar, the need for acquiring detailed voltage maps may be obviated.