1986; Brodde 1991; Jensen et al. 2009). β3ARs are a third subtype of cardiomyocyte βAR. Their role in the heart, however, is still largely unclear. They induce distinct intracellular signalling pathways and a negative inotropic effect. Since their expression is increased in several subtypes of human cardiomyopathy, they may have a potential role in heart failure. Mice with cardiac β3AR overexpression showed reduced hypertrophic remodelling through nitric oxide synthase activation (Balligand 2013; Belge et al. 2014). Here, ADRB2 is linked to heart failure.