ADRB1 and familial dilated cardiomyopathy: The reason why inhibition of the β1-GSN was confined to 2 of 3 of the patients with DCM is being investigated in a current clinical trial testing the hypothesis that reversal of remodeling and adverse β1-GSN signaling by β1-AR blockade is dependent on a permissive effect of adequate heart rate reduction (47), as nonresponders in this study did not exhibit a reduction in heart rate.