Contributions of Epi-, Endo- and Myocardium to the Body Surface Potential

The contribution of the epi-and endocardial as well as the myocardial electrical activity to the body surface potential was investigated in this study. A volume conductor including a realistic anisotropic ventricular model was built up and the forward problem of electrocardiography was solved for four different rhythms, in order to quantitatively describe the cardiac electrical contribution of each compartment of the heart. The results show, that the body surface potentials depend to a high degree on the epi-and endocardial electrical spread of excitation during the depolarization phase, whereas the influence of myocardial activity is more pronounced during repolarization. These findings indicate that the depolarization phase can be approximated by cardiac isotropic electrical.