ADRB3 and hydrops fetalis: Therefore, the purposes of the present study were 1) to determine whether HF patients could produce β3-AR Abs, 2) to investigate whether β3-AR Abs could affect the cardiac function in rats with abdominal aortic banding, and 3) to study the biological activities of these autoantibodies on cardiomyocytes in an attempt to explore its possible mechanisms.