Adaptive Modeling of Ionic Membrane Currents Improves Models of Cardiac Electromechanics

A change in activation sequence by means of pacing induceschanges in action potential (AP) morphology andduration. These changes are caused by electrical remodelingof ionic membrane currents and are reflected in theT wave in the electrocardiogram (ECG). Also the calciumtransient is affected, which leads to changes in cardiomechanics.By modeling the cardiac muscle as a single fiber,we investigated whether electrical remodeling may be triggeredby changes in mechanical load. A homogeneousdistribution of electrophysiology in our model resulted inan inhomogeneous distribution of stroke work. After remodelingof the ionic membrane currents, contraction wasmore homogeneous and the repolarization wave was reversed.These results are in agreement with experimentallyobserved homogeneity in mechanics and heterogeneityin electrophysiology. In conclusion, adaptive modelingof electrophysiology may improve current models of cardiacelectromechanics.