HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 297/4/H1521    most recent 01066.2008v1 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 Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Weber dos Santos, R. Articles by Giles, W. R. PubMed PubMed Citation Articles by Weber dos Santos, R. Articles by Giles, W. R.

Experimental and theoretical ventricular electrograms and their relation to electrophysiological gradients in the adult rat heart

¹Department of Computer Science, Universidade Federal de Juiz de Fora, Juiz de Fora, Brazil; ²Department of Physiology and Biophysics, ³Department of Electrical and Computer Engineering, ⁴Centre for Bioengineering Research and Education, and ⁷Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada; ⁵Institute of Biophysics, Medical University of Graz, Graz, Austria; and ⁶Department of Biosignals, Physikalisch-Technische Bundesanstalt, Berlin, Germany

Submitted October 2, 2008 ; accepted in final form August 18, 2009

The electrical activity of adult mouse and rat hearts has been analyzed extensively, often as a prerequisite for genetic engineering studies or for the development of rodent models of human diseases. Some aspects of the initiation and conduction of the cardiac action potential in rodents closely resemble those in large mammals. However, rodents have a much higher heart rate and their ventricular action potential is triangular and very short. As a consequence, an interpretation of the electrocardiogram in the mouse and rat remains difficult and controversial. In this study, optical mapping techniques have been applied to an in vitro left ventricular adult rat preparation to obtain patterns of conduction and action potential duration measurements from the epicardial surface. This information has been combined with previously published mathematical models of the rat ventricular myocyte to develop a bidomain model for action potential propagation and electrogram formation in the rat left ventricle. Important insights into the basis for the repolarization waveform in the ventricular electrogram of the adult rat have been obtained. Notably, our model demonstrated that the biphasic shape of the rat ventricular repolarization wave can be explained in terms of the transmural and apex-to-base gradients in action potential duration that exist in the rat left ventricle.

cardiac electrophysiology; electrocardiogram; potassium currents; mathematical models; voltage-sensitive dyes