Effects of acute ischemia and its components on the safety factor of conduction: a simulation study

In this work, we have studied the changes that acute myocardial ischemia exerts in our formulation of the safety factor of conduction (SF_m) which consists on a modification of the SF proposed by Shaw and Rudy. Specifically, the effect of each component of ischemia (hyperkalemia, hypoxia and acidosis) was studied separately, and also the evolution of the SF_m after the onset of ischemia was obtained. The results show that a) the three components of ischemia tend to reduce SF_m (except mild hyperkalemia), with strong hyperkalemia being the most important one and with hypoxia playing a mayor role only at high extracellular K concentration ([K⁺]o), and b) the SF_m decreases continuously as ischemia progresses