During acute myocardial ischemia, accumulation of K+ in the extracellular medium plays a major role in the development of reentrant arrhythmias. The Luo- Rudy (phase II) model for the ventricular action potencial, completed with the formulation of the IK(ATP) by Ferrero et al., was used to simulate conditions of acute myocardial ischemia. A Na+-H+ countertransport was also formulated and introduced into the model to balance ion concentrations in normoxia. The IK(ATP) current was activated during ten minutes of ischemia in a linear fashion from 0% to different maximum degrees. The effect of heart rate was studied considering different frecuencies of stimulation. Our results show that the maximal [K+]o increment due to IK(ATP) is less than 25% of the experimentally observed [K+]o accumulation. These data support the hypothesis than other mechanisms must be responsible for the rest of the [K+]o, increase.
ASJC Scopus subject areas
- Computer Science Applications
- Cardiology and Cardiovascular Medicine