ADRB3 and myocardial infarction: Although cardiac β3AR levels are low in physiological conditions [40], β3AR signaling seems to play a beneficial role in myocardial conditions such as acute myocardial infarction [1, 4, 12, 21, 28, 50, 68, 75], and β3AR expression is upregulated in the hearts of HF patients [46].