On the polyphasic charactcr of simulated and experimental electrograms

I I n · a i i i sn tmpie spreatl of excitation in the heart, the a.sst mated potent ia l patterns and the shape of the EGs ieleet ι ob t a in s ) are inllnenced by the direction of the mxncard ia l fibers, the anisotropy ratio of the intraand e\i ι a-< e l ln lar conductance, the extracardiac· conducting media and the reference potential. The shape of the QKS complexes varies from monophasic to polyphasic. In '."> we investigated the influence of the reference pot e n t i a l on the shape of unipolar EGs in a large slab of mvocardium wi th rotational anisotropy, by subdividing the EGs into an axial and a conormal component, hi subsequent papers [1. 2] the investigation was extended to an ellipsoidal model of the left ventricular wall: in both eases only a point stimulation on the epicardimn was considered and the analysis was confined to the depolarization phase. In the present paper we use a similar model of the left ventricle, including a Minplil ied Purkinje network, to study the complete EGs (excitat ion and repolarization) elicited by endocardial s t imulat ion.