This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Oster, H. S. Articles by Rudy, Y. Search for Related Content PubMed PubMed Citation Articles by Oster, H. S. Articles by Rudy, Y.

(Circulation. 1998;97:1496-1507.)
© 1998 American Heart Association, Inc.

Basic Science Reports

Electrocardiographic Imaging

Noninvasive Characterization of Intramural Myocardial Activation From Inverse-Reconstructed Epicardial Potentials and Electrograms

Howard S. Oster, MD, PhD; Bruno Taccardi, MD, PhD; Robert L. Lux, PhD; Philip R. Ershler, PhD; ; Yoram Rudy, PhD

From the Cardiac Bioelectricity Research and Training Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio (H.S.O., Y.R.); and the Cardiovascular Research and Training Institute, University of Utah, Salt Lake City (B.T., R.L.L., P.R.E.).

Correspondence to Yoram Rudy, Director, Cardiac Bioelectricity Research and Training Center, Case Western Reserve University, Wickenden Bldg, Room 505, Cleveland, OH 44106-7207. E-mail yxr{at}po.cwru.edu

Background—A recent study demonstrated the ability of electrocardiographic imaging (ECGI) to reconstruct, noninvasively, epicardial potentials, electrograms, and activation sequences (isochrones) generated by epicardial activation. The current study expands the earlier work to the three-dimensional myocardium and investigates the ability of ECGI to characterize intramural myocardial activation noninvasively and to relate it to the underlying fiber structure of the myocardium. This objective is motivated by the fact that cardiac excitation and arrhythmogenesis involve the three-dimensional ventricular wall and its anisotropic structure.

Methods and Results—Intramural activation was initiated by pacing a dog heart in a human torso tank. Body surface potentials (384 electrodes) were used to compute epicardial potentials noninvasively. Accuracy of reconstructed epicardial potentials was evaluated by direct comparison to measured ones (134 electrodes). Protocols included pacing from five intramural depths. Epicardial potentials showed characteristic patterns (1) early in activation, central negative region with two flanking maxima aligned with the orientation of fibers at the depth of pacing; (2) counterclockwise rotation of positive potentials with time for epicardial pacing, clockwise rotation for subendocardial pacing, and dual rotation for midmyocardial pacing; and (3) central positive region for endocardial pacing. Noninvasively reconstructed potentials closely approximated these patterns. Reconstructed epicardial electrograms and epicardial breakthrough times closely resembled measured ones, demonstrating progressively later epicardial activation with deeper pacing.

Conclusions—ECGI can noninvasively estimate the depth of intramyocardial electrophysiological events and provides information on the spread of excitation in the three-dimensional anisotropic myocardium on a beat-by-beat basis.

Key Words: electrocardiography • imaging • pacing • epicardium • potentials • anisotropy

This article has been cited by other articles:

				C. Ramanathan, P. Jia, R. Ghanem, K. Ryu, and Y. Rudy Activation and repolarization of the normal human heart under complete physiological conditions PNAS, April 18, 2006; 103(16): 6309 - 6314. [Abstract] [Full Text] [PDF]

				A. Berruezo, L. Mont, S. Nava, E. Chueca, E. Bartholomay, and J. Brugada Electrocardiographic Recognition of the Epicardial Origin of Ventricular Tachycardias Circulation, April 20, 2004; 109(15): 1842 - 1847. [Abstract] [Full Text] [PDF]

				C. Vahlhaus, H.-J. Bruns, J. Stypmann, T. D.T Tjan, F. Janssen, M. Schafers, H. H Scheld, O. Schober, G. Breithardt, and T. Wichter Direct epicardial mapping predicts the recovery of left ventricular dysfunction in chronic ischaemic myocardium Eur. Heart J., January 2, 2004; 25(2): 151 - 157. [Abstract] [Full Text] [PDF]

				J. E. Burnes, B. Taccardi, P. R. Ershler, and Y. Rudy Noninvasive electrocardiogram imaging of substrate and intramural ventricular tachycardia in infarcted hearts J. Am. Coll. Cardiol., December 1, 2001; 38(7): 2071 - 2078. [Abstract] [Full Text] [PDF]

				J. E. Burnes, R. N. Ghanem, A. L. Waldo, and Y. Rudy Imaging Dispersion of Myocardial Repolarization, I: Comparison of Body-Surface and Epicardial Measures Circulation, September 11, 2001; 104(11): 1299 - 1305. [Abstract] [Full Text] [PDF]

				R. N. Ghanem, J. E. Burnes, A. L. Waldo, and Y. Rudy Imaging Dispersion of Myocardial Repolarization, II: Noninvasive Reconstruction of Epicardial Measures Circulation, September 11, 2001; 104(11): 1306 - 1312. [Abstract] [Full Text] [PDF]

				J. E. Burnes, B. Taccardi, and Y. Rudy A Noninvasive Imaging Modality for Cardiac Arrhythmias Circulation, October 24, 2000; 102(17): 2152 - 2158. [Abstract] [Full Text] [PDF]

				J. E. Burnes, B. Taccardi, R. S. MacLeod, and Y. Rudy Noninvasive ECG Imaging of Electrophysiologically Abnormal Substrates in Infarcted Hearts : A Model Study Circulation, February 8, 2000; 101(5): 533 - 540. [Abstract] [Full Text] [PDF]