Electrical Activation of Sinus Venosus Myocardium and Expression Patterns of RhoA and Isl‐1 in the Chick Embryo

Abstract

Results show an initially bilateral electrical potential of sinus venosus myocardium evolving into a right-sided activation pattern during development, and suggest a role for RhoA in conduction system development. We hypothesize an initial sinus venosus-wide capacity to generate pacemaker signals, becoming confined to the definitive SAN. Lack of differentiation toward a chamber phenotype would explain ectopic pacemaker foci.