Single-Beat Noninvasive Imaging of Cardiac Electrophysiology of Ventricular Pre-Excitation

Berger, Thomas; Fischer, G.; Pfeifer, Bernhard; Modre, R.; Hanser, Friedrich; Trieb, Thomas; Roithinger, Franz Xaver; Stuehlinger, Markus; Pachinger, Otmar; Tilg, Bernhard; Hintringer, Florian

doi:10.1016/j.jacc.2006.08.019

Cited by 87 publications

(89 citation statements)

References 17 publications

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“…From these measurements, an inverse problem that requires accurate knowledge of the geometry of the organs and structures located at and between the measurement surface and the heart muscle then needs to be solved. For example, newly developed electrocardiographic imaging methods based on high-density body surface potential maps are most promising (4,5) and clinically relevant (6,31) in that regard. Although possessing undeniable qualities, these methods require either ionizing exposure [i.e., three-dimensional computed tomography (5)] or MRI (6), which can be contraindicated for patients with pacemakers or stents.…”

Section: Discussionmentioning

confidence: 99%

Imaging the electromechanical activity of the heart in vivo

Provost

Lee

Fujikura

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

100

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Cardiac conduction abnormalities remain a major cause of death and disability worldwide. However, as of today, there is no standard clinical imaging modality that can noninvasively provide maps of the electrical activation. In this paper, electromechanical wave imaging (EWI), a novel ultrasound-based imaging method, is shown to be capable of mapping the electromechanics of all four cardiac chambers at high temporal and spatial resolutions and a precision previously unobtainable in a full cardiac view in both animals and humans. The transient deformations resulting from the electrical activation of the myocardium were mapped in 2D and combined in 3D biplane ventricular views. EWI maps were acquired during five distinct conduction configurations and were found to be closely correlated to the electrical activation sequences. EWI in humans was shown to be feasible and capable of depicting the normal electromechanical activation sequence of both atria and ventricles. This validation of EWI as a direct, noninvasive, and highly translational approach underlines its potential to serve as a unique imaging tool for the early detection, diagnosis, and treatment monitoring of arrhythmias through ultrasoundbased mapping of the transmural electromechanical activation sequence reliably at the point of care, and in real time.strain | electromechanical coupling T he heart is an electromechanical pump that requires to first be electrically activated in order to contract. In the normal heart, action potentials are spontaneously generated by the sinus node in the right atrium and propagate through a specialized conduction system before reaching the cardiac muscle. The depolarization of a cardiac muscle cell, or myocyte, is followed by an uptake of calcium, which triggers contraction (1) after an electromechanical delay of a few milliseconds (2, 3). In the clinical setting, the electrical and mechanical functions of the heart are typically evaluated separately. The cardiac electrical function is usually assessed using an electrocardiogram (ECG) or catheter-based mapping systems. New noninvasive imaging technologies based on body surface potentials (4-6), cavity potentials (7), or magnetic fields (8) are also being developed. Methods used to measure the cardiac electrical activity typically ignore the cardiac motion. On the other hand, the cardiac mechanical function can be assessed using ultrasound or magnetic resonance (MR) techniques, but at such large time scales that the electrical activation occurs within one time frame and is hence ignored. In the laboratory, the cardiac electromechanical coupling has been and remains the topic of extensive research at the cellular level in vitro (3), in cardiac simulation models (9-12), and at the tissue level in animal models in vivo (2,(13)(14)(15). To perform such studies, it is necessary to map the electromechanics of the heart (i.e., the deformations occurring at the time scale of the electrical activation). For example, in refs. 13 and 14, a linear relationship between the electrical ac...

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Section: Discussionmentioning

confidence: 99%

Imaging the electromechanical activity of the heart in vivo

Provost

Lee

Fujikura

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

100

View full text Add to dashboard Cite

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“…However, inverse solutions that use homogeneous models seem to be less accurate in vivo. [21][22][23][24] The need to incorporate inhomogeneities in inverse mapping techniques, which could be used in a clinical setting has been widely debated. On the one hand, it has been shown that inhomogeneous inverse solutions correspond more closely with epicardial potential maps in the absence of noise.…”

Section: Why Does the Forward Problem Of Electrocardiography Matter?mentioning

confidence: 99%

Forward Problem of Electrocardiography

Bear

Cheng

LeGrice

et al. 2015

Circ: Arrhythmia and Electrophysiology

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Background-The relationship between epicardial and body surface potentials defines the forward problem of electrocardiography. A robust formulation of the forward problem is instrumental to solving the inverse problem, in which epicardial potentials are computed from known body surface potentials. Here, the accuracy of different forward models has been evaluated experimentally. Methods and Results-Body surface and epicardial potentials were recorded simultaneously in anesthetized closed-chest pigs (n=5) during sinus rhythm, and epicardial and endocardial ventricular pacing (65 records in total). Body surface potentials were simulated from epicardial recordings using experiment-specific volume conductor models constructed from magnetic resonance imaging. Results for homogeneous (isotropic electric properties) and inhomogeneous (incorporating lungs, anisotropic skeletal muscle, and subcutaneous fat) forward models were compared with measured body surface potentials. Correlation coefficients were 0.85±0.08 across all animals and activation sequences with no significant difference between homogeneous and inhomogeneous solutions (P=0.85). Despite this, there was considerable variance between simulated and measured body surface potential distributions. Differences between the body surface potential extrema predicted with homogeneous forward models were 55% to 78% greater than observed (P<0.05) and attenuation of potentials adjacent to extrema were 10% to 171% greater (P<0.03). The length and orientation of the vector between potential extrema were also significantly different. Inclusion of inhomogeneous electric properties in the forward model reduced, but did not eliminate these differences. Conclusions-These results demonstrate that homogeneous volume conductor models introduce substantial spatial inaccuracies in forward problem solutions. This probably affects the precision of inverse reconstructions of cardiac potentials, in which this assumption is made. (Circ Arrhythm Electrophysiol. 2015;8:677-684.

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“…Some qualitative models have also been developed [20,35] [40], and represents the excitation part of the monodomain RDE with two variables representing the depolarization and the repolarization of the cell membrane. Some analysis that measures the stability of excitable tissues in 2D using FHN and single or multiple noise sources is also presented [41,42].…”

Section: Electrical Excitation Methods Of Heart Tissuementioning

confidence: 99%

Modeling of realistic heart electrical excitation based on DTI scans and modi ed reaction diffusion equation

2018

Turk J Elec Eng & Comp Sci

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Abstract:A new method is proposed for modeling realistic heart activation using diffusion tensor imaging (DTI) scans based on biological properties of its tissues in addition to the working methodology of the DTI scanner. Modeling of the excitation propagation inside the heart is initiated by applying activation at only one pacing site at the root of the conduction network. The excitation propagation has been accomplished based on a proposed conduction system that is extracted from DTI heart scans and a modified version of monodomain reaction diffusion equation (RDE) that considers the heart inhomogeneous-anisotropic material. The Aliev-Panfilov method was used to model the reaction part of the equation and inhomogeneous-anisotropic diffusion to model the diffusion part in the equation. Variation in conduction speeds between the myocardium and the conduction system has been also taken into consideration. Employing the proposed conduction system and the modified RDE on the heart model shows (somewhat) realistic heart activation where the produced ventricular excitation propagation isochrones are similar to real measurements.

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Single-Beat Noninvasive Imaging of Cardiac Electrophysiology of Ventricular Pre-Excitation

Cited by 87 publications

References 17 publications

Imaging the electromechanical activity of the heart in vivo

Imaging the electromechanical activity of the heart in vivo

Forward Problem of Electrocardiography

Modeling of realistic heart electrical excitation based on DTI scans and modi ed reaction diffusion equation

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