od______2367::0001a50c6388e9bfcb791a924ec4b837 oai:pumaoai.isti.cnr.it:cnr.imati/cnr.ian.pv/1999-PP-018 10d18b66-1d2a-4579-9adc-aa57b0821c7f_UmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZXMvUmVwb3NpdG9yeVNlcnZpY2VSZXNvdXJjZVR5cGU= 2016-11-22T09:15:30.817Z 2016-11-22T09:18:15.904Z od______2367

Anisotropic mechanisms for multiphasic unipolar electrograms. Simulation studies and experimental recordings Colli Franzone, Piero, Guerri, Luciano, Pennacchio, Micol, Taccardi, Bruno 1999-09-30 The origin of the multiple, complex morphologies observed in unipolar epicardial electrograms, and their relationships with myocardial architecture, have not been fully elucidated. To clarify this problem we simulated electrograms (EGs) with a model representing the heart as an anisotropic bidomain with unequal anisotropy ratio, ellipsoidal ventricular geometry, transmural fiber rotation, epi-endocardial obliqueness of fiber direction and a simplified conduction system. The electrograms were compared with those directly recorded from the surface of isolated dog hearts immersed in a conducting medium. The model accurately reproduced the recorded EG morphologies for excitation wave fronts that reach the recording sites by spreading either along or across fibers.The origin of the multiple waves that constitute the QRS complex could be better understood after splitting the current sources, the potential distributions and the EGs into a field component (further subdivided into an axial and a conormal component) and a "reference" component. The split model provides an explanation of the interaction between the three-dimensional geometry and direction of propagation of a spreading wave front, the architecture of the fibers through which excitation is spreading, the potential distributions and the QRS wave forms. Because epicardial potentials, electrograms and isochrone contours can be computed noninvasively from body surface measurements, interpreting epicardial EGs in terms of intramural events may have clinical relevance. http://puma.isti.cnr.it/dfdownloadnew.php?ident=cnr.imati/cnr.ian.pv/1999-PP-018 http://puma.isti.cnr.it/rmydownload.php?filename=cnr.imati/cnr.ian.pv/1999-PP-018/1999-PP-018_0.ps eng Preprint ercim.cnr.ian//1999-1151, 1999. Electrograms, bidomain model, reference potential, cardiac potential maps, anisotropic propagation, source splitting info:eu-repo/classification/msc/78A70,65N30 info:eu-repo/semantics/openAccess info:eu-repo/semantics/preprint 0016 1999-09-30 opendoar____::2367 OPEN http://pumaoai.isti.cnr.it/openoai2.php oai:pumaoai.isti.cnr.it:cnr.imati/cnr.ian.pv/1999-PP-018 1999-10-08 http://www.openarchives.org/OAI/2.0/oai_dc/ false false 0.9