Simulation of reentry during acute myocardial ischemia: role of ATP-sensitive potassium current and acidosis

In this work, the authors use a modified version of the Luo-Rudy (phase II) model to study the role of hyperkalemia, hypoxia and acidosis in the establishment of “figure of eight reentry”. For this purpose, the electrical activity of a ring-shaped simulated tissue comprising normal zone, ischemic borderzone and ischemic central zone was simulated. Tissue vulnerability to reentry was determined by measuring the vulnerable window (VW) by delivering different extrastimuli under different tissue conditions. The results suggest that hypoxia (simulated by activating the ATP-sensitive potassium current) could be the most pro-arrhythmic component of ischemia, while acidosis could have antiarrhythmic effects on the short term