Drift of Scroll Wave Filaments in an Anisotropic Model of the Left Ventricle of the Human Heart

Scroll waves are three-dimensional vortices which occur in excitable media. Their formation inthe heart results in the onset of cardiac arrhythmias, and the dynamics of their filaments determinethe arrhythmia type. Most studies of filament dynamics were performed in domains with simplegeometries and generic description of the anisotropy of cardiac tissue. Recently, we developed ananalytical model of fibre structure and anatomy of the left ventricle (LV) of the human heart. Here,we perform a systematic study of the dynamics of scroll wave filaments for the cases of positive andnegative tension in this anatomical model. We study the various possible shapes of LV and differentdegree of anisotropy of cardiac tissue. We show that, for positive filament tension, the final positionof scroll wave filament is mainly determined by the thickness of the myocardial wall but, however,anisotropy attracts the filament to the LV apex. For negative filament tension, the filament buckles,and for most cases, tends to the apex of the heart with no or slight dependency on the thickness ofthe LV. We discuss the mechanisms of the observed phenomena and their implications for cardiacarrhythmias.