The effect of scar tissue on complexity of activation patterns in simulated human Ventricular Fibrillation

Ventricular Fibrillation (VF) is a severe cardiac arrhythmia. Early experiments provided evidence that the mechanism of VF is consistent with re-entry. In 3D the sources of re-entrant waves are lines of phase singularity called filaments. Filament interactions and filament numbers can be used to quantify the complexity of activation patterns in simulated VF. In this study we investigated how filament dynamics are affected by the presence of uniform and non-uniform simulated scars using computational models. A half ellipsoid representing an idealized human left ventricle with similar apex base dimension and wall thickness was used in the present study. The region of simulated scar was either uniform or contained a random mixture of excitable and inexcitable tissue. Increasing the radius of uniform scar increased the number of filaments compared to non-uniform scar. The size and the configuration of scar influenced the filament shape and numbers. Overall the uniform scar had more effect on filament dynamics compared to the non-uniform scar.