ADRB2 and heart failure: Heart failure (HF) is characterized by impaired βAR signaling, which manifests in different ways, for example: an increase in β2AR signaling due to the decrease in β1AR expression10; an attenuated augmentation of the LTCC current by beta-adrenergic stimulation11; and the restrictive β2AR cAMP signaling in the TT become global and less dependent on phosphodiesterase inhibition.7