Related Papers
Computing in cardiology
Controlled Activation for Interrogation of the Electrophysiological Substrate
2014 •
ravi ranjan
Ectopic activation and conduction may give rise to arrhythmias when a diseased myocardial substrate exists. Electrophysiological mapping studies that record electrical properties of the heart in sinus rhythm may fail to uncover pro-arrhythmic substrates that are triggered by ectopy. In this study we use simulation and experimental models of clinical, trackable, loop catheters to interrogate regions of myocardium by stimulating and recording with multiple activation patterns. Longitudinal and traverse conduction velocities of the tissue were acquired from the pacing protocol. Artifacts resulting from variable distance between the recording electrodes and pacing site were also detected and removed. This study demonstrates that the mapping of local tissue properties with variable activation patterns is feasible and can expose features of the electrophysiological substrate that can not be recovered during sinus conduction.
Pacing and Clinical Electrophysiology
Origin of Electrical Activation Within the Right Atrial and Left Ventricular Walls:. Differentiation by Electrogram Characteristics Using the Noncontact Mapping System
2003 •
Thomas Kriebel
Journal of Electrocardiology
Activation patterns during selective pacing of the left ventricle can be characterized using noninvasive electrocardiographic imaging
2007 •
Michael Roberts
Noncontact endocardial mapping allows accurate beat-to-beat reconstruction of the reentrant pathway of ventricular tachycardia and improves outcomes after ablation. Several studies support electrocardiographic imaging (ECGI) as a means of noninvasively outlining epicardial activation despite constraints of internal geometry. However, few have explored its clinical application. This study aims to evaluate ECGI during selective left ventricular (LV) pacing, relative to an invasive approach. Multisite pacing was performed within the left ventricles of 3 patients undergoing invasive procedures. Simultaneous recording of endocardial potentials using a noncontact multielectrode array and body surface potentials (BSP) using an 80-electrode torso vest was performed. A total of 16 recordings were made. The inverse solution was applied to BSP to reconstruct epicardial activation. Single-paced beats from real and virtual electrograms were used to construct 3-dimensional isochronal and isopotential maps. Endocardial and epicardial data were then superimposed onto a single geometry to allow quantitative comparison of activation foci. Good correlation was observed between endocardial activation patterns and those reconstructed from BSP using ECGI. This was repeatedly demonstrated in all LV regions except for the septum (3 recordings). Epicardial isochronal maps were able to locate early and late activation to mean distances of 13.8 +/- 4.7 and 12.5 +/- 3.7 mm from endocardial data. Isopotential maps localized pacing sites with comparable accuracy (14 +/- 5.3 mm). Body surface potentials and reconstructed epicardial activation patterns during LV pacing correlate well with endocardial data acquired invasively. The exception was during pacing of the septum. Although early results are encouraging, further quantitative data are required to fully validate and apply this noninvasive tool in the clinical arena.
Electroanatomical Mapping Systems. An Epochal Change in Cardiac Electrophysiology
Carmine Garzillo
In the last two decades new mathematical and computational models and systems have been applied to the clinical cardiology, which continue to be developed particularly to quantify and simplify anatomy, physio-pathological mechanisms and treatment of many patients with cardiac arrhythmias. The Authors report our large experience on electroanatomical mapping systems and techniques that are currently used to quantify and analyze both anatomy and electrophysiology of the heart. In the last 15 years the Authors have performed more than 15,000 invasive catheter ablation procedures using different non-fluoroscopic three-dimensional (3D) elec-troanatomical mapping and ablation systems (CARTO, Ensite) to safely and accurately treat many patients with different cardiac arrhythmias particularly those with atrial fibrillation with a median age of 60 years (IQR, 55-64). The Authors have also developed and proposed for the first time a new robotic magnetic system to map and ablate cardiac arrhythmias without use of fluoroscopy (Stereotaxis) in >500 patients. Very recently, epicardial mapping and ablation by electroanatomical systems have been successfully performed to treat Brugada syndrome at risk of sudden death in a series of patients with a median age of 39 years (IQR, 30-42). Our experience indicates that electroanatomic mapping systems integrate several important func-tionalities. (1) Non-fluoroscopic localization of electrophysiological catheters in three-dimensional space; (2) Analysis and 3D display of cardiac activation sequences computed from local or calculated electrograms, and 3D display of electrogram voltage; (3) Integration of 'electroanatomic' data with non-invasive images of the heart, such as computed tomography or magnetic resonance images. The widespread use of such 3D systems is associated with higher success rates, shorter fluoroscopy and procedure times, and accurate visualization of complex cardiac and extra-cardiac anatomical structures needing to be protected during the procedure.
Annals of Biomedical Engineering
Model Study of Vector-Loop Morphology During Electrical Mapping of Microscopic Conduction in Cardiac Tissue
2001 •
Gernot Plank
The large variety in loop morphology of potential differences recorded at the cardiac surface has been generally attributed to structural discontinuities of the tissue. The aim of this work was to examine if the diversity of vector loops of the electric field E found experimentally may also arise during continuous anisotrope conduction. For this purpose a monodomain computer model was used, consisting of a two-dimensional sheet of excitable tissue surrounded with an unbounded volume conductor. Close to the tissue surface our computations predicted a narrow biphasic course of Φe with peak-to-peak separation of less than 400 μm. We examined how accurately E could be reconstructed from measurements recorded with four-element electrode arrays and how activation sequence, interelectrode spacing, and probe orientation affects the results. We found “closed” vector loops of E in planar, and at the apex of elliptical wave fronts, whereas outside of these regions vector loops were “open.” Varying probe orientation and size resulted in substantial changes of vector-loop morphology. We concluded that close to the cardiac current sources accurate measurement of E would require interelectrode distances of less than 100 μm. © 2000 Biomedical Engineering Society. PAC00: 8719Nn, 8719Hh
Biomedizinische Technik/Biomedical Engineering
Feasibility of activation time imaging within the human atria and ventricles in the catheter laboratory
2001 •
Christian Kremser
IEEE Transactions on Medical Imaging
Model-Based Imaging of Cardiac Electrical Excitation in Humans
2002 •
Bernd Messnarz
Ieee Signal Processing Magazine
Electrical imaging of the heart
1997 •
Robert MacLeod
Coronary Artery Disease
Effects of electrode size and spacing on the resolution of intracardiac electrograms
2012 •
Nathaniel Thompson
Journal of Electrocardiology
ECG waveforms and cardiac electric sources
1996 •
Robert MacLeod
