The fetal heart in diaphragmatic hernia.

Cardiac evaluation is an important part of the investigation of a fetus with a diaphragmatic hernia. The heart is displaced by the physical presence of the abdominal contents in the chest, and the flow dynamics within the heart are altered. This can produce secondary diminution of chamber growth, particularly of the left heart. Structural heart malformation is also a frequently associated finding. Evaluation of cardiovascular flow profiles may give us further understanding of the pathophysiology of this lesion and may help to predict those fetuses that might benefit from intrauterine therapy.