GJA1 and high output heart failure: Accordingly, we studied the effects of chronic administration of Cx43 mimetic peptide Gap27 on the progression of cardiac dysfunction, incidence of cardiac arrhythmias, cardiac function and cardiac remodeling in rats with high-output heart failure (AV-shunt) a well-characterized model of non-ischemic heart disease with neurohumoral activation, sympatho-excitation and cardiac dilation18–20.