The Combined Effect of Myocardial Infarction and Ischemia on Excitation Wave Propagation in Ventricular Tissue

Cuiping Liang1, Kuanquan Wang1, Qince Li1, Henggui Zhang2
1Harbin Institute of Technology, 2University of Manchester


Aims: Previous studies have shown that the infarction or ischemia of cardiac tissue can change the electrophysiological properties of the heart, and are strongly correlated with incidence of atrial and ventricular tachyarrhythmias. In the case of myocardial ischemia reoccurrence in myocardial infarcted tissue of patients, myocardial infarction and ischemia may coexist in the same heart tissue. However, so far their combined effect on the genesis of cardiac arrhythmias has not been fully understood. Therefore, this study aimed to investigate how the coexistence of myocardial infarction and ischemia alters excitation wave propagation. Methods: Firstly, the electrophysiology remodeling under ischemia condition was mimicked based on experimental data and incorporated into TP06 model. In addition, 2D and 3D realistic ventricular models were constructed based on MRI images in which the non-infarcted and infarcted areas are separated according to different pixel intensities. Using the constructed 2D and 3D models, we simulated the excitation wave conduction in ventricular tissue under four different conditions: normal, myocardial infarction, myocardial ischemia and myocardial infarction with ischemia conditions. Results: Simulation results showed that the conduction velocity and rotor tracks are different in the normal, infarcted and ischemic conditions. In addition, reentry waves are observed in myocardial infarction with the ischemic condition in 2D and 3D models. Conclusion: Simulation results demonstrate that the coaction of myocardial infarction and ischemia areas increases spatial electrical heterogeneity of ventricular tissue and irregularity of rotor tracks, which may enhance the pro-arrhythmogenic effect.