CTBP1 and hydrops fetalis: β-blockers contribute to the restoration of the downregulated β-ARs due to HF and, as a consequence, lead to an improvement in LV function.17–19 Interestingly, carvedilol (a mixed α1- and β-blocker) does not restore the number of β-ARs but does recouple the existing receptors and improves the signaling pathway efficiency.20 Long-term studies have shown β-blockers to reverse remodeling by decreasing LV mass and to revise ventricular shape to a more normal, elliptical appearance.