Simulation of ECG using a heart model with reaction-diffusion action potentials

The present work describes a three-dimensional model of the heart, the depolarization and repolarization processes and generation of the ECG waveform. The model consists of the atria and the ventricles with a conduction system. The action potential of the cells is governed by a reaction-diffusion state equations which exhibit variable stability, amplitude, duration and differentiate between depolarization and repolarization cellular mechanisms, for the various cardiac components. The model is heterogeneous with rotational anisotropy and of close relation to the physio-anatomical cardiac environment. The ECG is simulated by summing the dipole contributions of all cells. Action potentials from various locations and activation isochrones are shown. A diffusion coefficient of 0.055 to 0.5 mm²msec^-1 is obtained from the physiological scaling.