Session P84.8

Simulation of Effects of Ischemia in 3D Human Ventricle

WG Lu, TJ Liu, WM Zuo*, KQ Wang, HG Zhang

Harbin Institute of Technology
Harbin City , China

Cardiac arrhythmia is the most common heart disease, which is closely associated with abnormal wave propagation caused by reentrant sources of excitation. Thus it would be of great importance to study the modeling of cardiac electrical activity using biophysically detailed cellular models with realistic 3D anatomical geometry and to study the behavior of reentrant waves and their relation to arrhythmias. In this paper, we present an integrated model of 3D human ventricle to simulate the effects of ischemia on wave propagation. The integrated model includes three major components: (1) First, to model the action potential of single cell, we adopt the TNNP model, which is based on recent experimental data on human ventricular cell and consists of 17 variables. (2) Second, monodomain model is used to model the wave propagation of cardiac tissue. (3) Third, we simulate the wave propagation behavior of ischemia on the human ventricular tissue provided by Visible Human Project (http://www.nlm.nih.gov/research/visible/visible_human.html ). Due to the complex geometries of ventricular tissue, precise treatment of boundary conditions would be complicated. To deal with the no-flux boundary conditions, a phase-field method is employed. The major advantage of the method is that it can automatically handle the boundary conditions by introducing an auxiliary field to smooth the interface between the interior and the exterior of cardiac tissue, which decreases the complexity of computation on the premise of maintaining the accuracy. Based on the above model, we simulate the wave propagation of human ventricular tissue with ischemia symptom through the increasing of concentration of extracellular K+ and ischemic size. We further simulate the propagation of spiral wave under different ischemia symptoms and explain the underlying mechanism that caused arrhythmia under myocardial ischemia. Finally, we simulate the scroll wave in the 3D anatomically detailed model of human ventricle. The results show that with the increasing of ischemia severity and ischemic size, spiral waves are more and more unstable, but when the tip of spiral wave staying inside the ischemic region, the spiral wave maintains stabilization.

(Abstract Control Number: 81)