Computer-simulated alternative modes of U-wave genesis.
OBJECTIVE
Several hypotheses for the origin of the U wave in electrocardiograms have been proposed. We have set out to explore and test alternative modes for U-wave genesis via computer simulations.


RESULTS
A spatial model of a left ventricle has been constructed from 12 layers composed of cubic cells. Each cell is assigned its own time-dependent action potential with its own contribution to the electrical potential at arbitrary points where ECGs are measured. Simulated ECGs show that U waves can be generated using various combinations of action potentials (APs) across the different layers of the ventricular wall. We demonstrate a new mode of U-wave genesis, even with small differences in the repolarization.


CONCLUSIONS
The U wave can be generated in the presence of strong intercellular coupling. Myocardial layers with prolonged action potentials, like M cells, are not necessarily needed for U-wave genesis.
Depolli
Matjaz
M
Department of Communication Systems, Jozef Stefan Institute, Ljubljana, Slovenia. matjaz.depolli@ijs.si
Avbelj
Viktor
V
Trobec
Roman
R
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D004562:Electrocardiography / Q000379:methods*; D006329:Heart Conduction System / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular; D032383:Myocytes, Cardiac / Q000502:physiology*; D016276:Ventricular Function