Understanding Ventricular Tachyarrhythmias Related to Acute Myocardial Ischemia: A Computational Modeling Approach

This paper describes a computational approach designed to study ventricular tachyarrhythmias arising from acute myocardial ischemia. Since these cardiac disorders can frequently lead to sudden cardiac death, understanding their mechanisms is key to improving their diagnosis and therapy. The use of computational simulations based on multiscale mathematical modeling has proved to be a powerful tool in unraveling the causes of this phenomenon. In the first part of this work, we reformulated a model of the ischemic human ventricular cell to simulate the features of the action potentials during acute ischemia. We then incorporated the model into an electrophysiologically-detailed three-dimensional virtual human heart, which was able to reproduce the typical ventricular tachyarrhythmias in the first 15 min of ischemia with rhythms resembling ventricular fibrillation. The results suggest that the extracellular potassium concentration and the presence of a wash-out subendocardial zone are key factors in the vulnerability of the ischemic myocardium to arrhythmias.