The effect of congenital diaphragmatic hernia on the development of left-sided heart structures

Patients with congenital diaphragmatic hernias often have concomitant congenital heart disease (CHD), with small left-sided cardiac structures as a frequent finding. The goal of this study is to evaluate which left-sided heart structures are affected in neonates with congenital diaphragmatic hernias. Retrospective review of neonates between May 2007 and April 2015 with a diagnosis of a congenital diaphragmatic hernia was performed. Clinical and echocardiographic data were extracted from the electronic medical record and indexed to body surface area and compared to normative values. Univariable regression models assessed for associations between different variables and length of stay. Data of 52 patients showed decreased mean z scores for the LVIDd (-3.16), LVIDs (-3.05), aortic annulus (-1.68), aortic sinuses (-2.11), transverse arch (-3.11), and sinotubular junction (-1.47) with preservation of the aorta at the diaphragm compared to age-matched normative data with similar body surface areas. Regression analysis showed a percent reduction in length of stay per 1 mm size increase for LVIDd (8%), aortic annulus (27%), aortic sinuses (18%), sinotubular junctions (20%), and transverse arches (25%). Patients with congenital diaphragmatic hernias have significantly smaller left-sided heart structures compared to age-matched normative data. Aortic preservation at the diaphragm provides evidence for a mass effect aetiology with increased right-to-left shunting at the fetal ductus resulting in decreased size. Additionally, length of stay appears to be prolonged with decreasing size of several of these structures. These data provide quantitative evidence of smaller left-sided heart structures in patients with congenital diaphragmatic hernias.