Adaptation of an action potential minimal model to acute ischemia

Simplified action potential ¿minimal¿ models, whilst not being able to explain the ionic mechanisms of cardiac action potential, can be useful for cardiac simulation purposes if the model possesses certain basic properties. In this work, we have analyzed one of these ¿minimal models¿ (the Bueno model) to investigate its ability to simulate ischemia. We modified the model by adding a new ischemic outward current and changing the fast inward current inactivation gate. The results show that the typical action potential shortening in ischemia is properly simulated, while the ischemic peak membrane potential decrease, the resting potential increase and post-repolarization refractoriness are qualitatively, but not quantitatively, reproduced. However, peak decrease and resting potential increase can be achieved by a further simple model modification. In conclusion, the ¿ischemic¿ behaviour of the model makes it suitable for simulations in which refractoriness is not a key factor.