Simulation of Action Potential Propagation Block on a Bidimensional Ventricular Tissue Model During Regional Myocardial Ischaemia
UNIVERSIDAD POLITECNICA DE VALENCIA (SPAIN)
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During the acute phase of myocardial ischemia, electrophysiological alterations in ventricular cells exacerbate serious arrhythmias such as reentries, Indeed, extracellular potassium accumulation in an ischemic zone reduces conduction velocity. Concomitantly, the activation of ATP dependent potassium current I sub ksub ATP under ischemic conditions provokes a reduction in action potential duration APD, creating inhomogeneities within the tissue, which represent the main cause of unidirectional block and reentry, In this work, we investigate the patterns of activation in an isotropic ischemic bidimensional tissue by means of computer simulations, Using the Luo-Rudy phase II model of ventricular action potential and the I sub k sub ATP formulation, we stimulated prematurely a bidimensional tissue of 5 cm2 with a normal zone, an ischemic zone and a border zone at different instants of time, to reproduce realistic conditions of reentry. Our results agree with experimental works and show the existence of a time interval window of block, in which propagation is blocked in the central zone of ischaemia.
- Anatomy and Physiology