Adaptive modeling of ionic membrane currents improves models of cardiac electromechanics

A change in activation sequence by means of pacing induces changes in action potential (AP) morphology and duration. These changes are caused by electrical remodeling of ionic membrane currents and are reflected in the T wave in the electrocardiogram (ECG). Also the calcium transient is affected, which leads to changes in cardiomechanics. By modeling the cardiac muscle as a single fiber, we investigated whether electrical remodeling may be triggered by changes in mechanical load. A homogeneous distribution of electrophysiology in our model resulted in an inhomogeneous distribution of stroke work. After remodeling of the ionic membrane currents, contraction was more homogeneous and the repolarization wave was reversed. These results are in agreement with experimentally observed homogeneity in mechanics and heterogeneity in electrophysiology. In conclusion, adaptive modeling of electrophysiology may improve current models of cardiac electromechanics.