A study on the relationship between electrical transmural heterogeneity and ventricular energetics

Although there are numerous reports on the electrical heterogeneity of the myocardium, little has been given attention to its relation to cardiovascular mechanics, because of difficulties of simultaneously observing multiple effects in vivo. In this research, a multi-scale cardiovascular simulation model, which describes the myocyte physiology, left ventricular structural dynamics, and hemodynamics, was used to theoretically investigate the relationshipbetween the electrical transmural heterogeneity of myocytes and ventricular energetics. The parameters which describe the characteristics of ion channels of an existing myocyte model were changed to create endo-, mid-, and epi-cardium myocyte models. Simulations were performed with electrically heterogeneous and homogeneous models. As a result, the heterogeneous model had lower contractility and higher total mechanical energy generation per ATP consumption. These findings indicate that electrical heterogeneity contribute to cardiac efficiency.