Computational Analysis of Vulnerability to Reentry in Acute Myocardial Ischemia

The influence of each ischemic component (hypoxia, hyperkalemia, and acidosis) on arrhythmogenesis is controversial and difficult to study experimentally. In the present study, we investigate how the different ischemic components affect the vulnerable window (VW) for reentry using computational simulations. Simulations were performed in a 3D biventricular model that includes a realistic ischemic region and the His-Purkinje conduction system. At the cellular level, we used a modified version of the O' Hara action potential model adapted to simulate acute ischemia. Three different levels of ischemia were simulated: mild, moderate, and severe. The effects on the width of the VW of each ischemic parameter were analyzed. The model allowed us to obtain a realistic reentrant pattern corresponding to ventricular tachycardia in all simulations. Results suggest that the ischemic level plays an important role in the generation of reentries. Furthermore, hypoxia has the most significant effect on the width of the VW The presence of Purkinje system is key to the generation of reentries.