Topographic Distribution of Passive Electric Properties in the Rabbit's Right Atrium

Abstract

In this study it was made attempt to find out values of parameters of intercellular coupling in sinoatrial nodal zone, from internal surface of rabbit’s heart by total investigation of passive electric properties. By using experimentally measured tissue input resistance R_in and distribution of electrotone near the suction electrode, maps of topographic distribution of R_in and l in the right atrium of the rabbit's heart were devised. Additionally, by using the model anisotropic electric properties (a_e=l_x/l_y) and the direction of best electrotonic spread (ETGSK) were calculated. It was found that in the area of true pacemaker locations R_in is significantly larger, l is smaller and anisotropy is insignificant. During the measurements, pathways of better electrotonic spread were found.