ADRB2 and heart failure: While these pathways generally have been implicated in cardioprotection, studies in cardiomyocytes also link chronic βAR activation the activation of proapoptotic pathways and a spectrum of changes (including cardiomyocyte hypertrophy and apoptosis, interstitial fibrosis, and contractile dysfunction) that contribute to the pathogenesis of heart failure (3, 4).