Correspondence Letter by Burchill et al Regarding Article, “Enalapril in Infants With Single Ventricle: Results of a Multicenter Randomized Trial” To the Editor:

Given the scarcity of rigorously designed trials in patients with congenital heart disease, Hsu et al must be commended for providing new insights into the effect of angiotensin-converting enzyme (ACE) inhibitors in infants with single ventricles.1 Increased somatic growth has been reported in children with valvular regurgitation who have been treated with ACE inhibitors.2 Whether this benefit translates to those born with univentricular physiology is an important question, given the burden of heart failure in this population. The absence of effective medical treatments in this cohort rein-forces the challenge of treating diastolic dysfunction, an early consequence of preload reduction in surgically palliated single-ventricle patients.3 Large-scale randomized, controlled trials have highlighted the limited efficacy of ACE inhibitors in reversing diastolic dysfunction and improving outcomes in adults with diastolic heart failure. Diastolic parameters have not yet been reported by Hs