Adrenergic deficiency leads to impaired electrical conduction and increased arrhythmic potential in the embryonic mouse heart

► Adrenergic deficiency leads to slowed atrioventricular conduction in embryonic mouse heart. ► Adrenergic deficiency leads to decreased expression of Cx43 in the embryonic heart. ► Adrenergic deficiency does not alter Hcn4 or sarcomeric α-actinin expression in heart development. ► Adrenergic deficiency leads to increased susceptibility to arrhythmia in the embryonic mouse heart.