Formulation of ATP sensitive K+ Current and Action Potential Shape in Models of Human Ventricular Myocytes

The contribution of the ATP-sensitive K+ (KATP+) current to the action potential is an important component of cardiac ischaemia. The purpose of this study was to investigate how the formulation of IK(ATP) influences action potential shape and duration in the Ten Tusscher-Panfilov 2006 model of human ventricular myocytes. We compared four different IK(ATP) formulations, which were inserted in the epicardial variant of the cell model embedded in a 2D monodomain tissue model. The results demonstrate that inserting IK(ATP) in the cell models shortens APD as intracellular ATP concentration is reduced, consistent with experimental findings. Although the current-voltage properties of each IK(ATP) formulation were different, each formulation had a similar effect on the properties of the tissue model.