The predominant determinant of outcome for patients with pulmonary atresia and an intact ventricular septum revolves around:

C. The size of the right ventricular cavity and tricuspid valve

DISCUSSION: The long-term outcome for babies with pulmonary atresia and intact ventricular septum depends on the ability to convert the cardiac circulation into a two-ventricle versus one-ventricle physiology. Patients with a good-sized right ventricle and tricuspid valve can often be treated with pulmonary valvotomy or right ventricular outflow patching alone and can have a fairly acceptable outcome. Patients with a small right ventricle that cannot provide adequate pumping to the pulmonary bed and is often associated with a small tricuspid valve annulus may need to be staged toward a Fontan procedure—and, consequently, a less acceptable outcome. The size of an ASD is not relevant except that in patients with this syndrome, the right side of the heart will decompress across the ASD until antegrade flow can be established. Therefore, an ASD in some part is an essential feature of this lesion. The degree of arterial hypoxemia, the nature of the pulmonary valve, and the patient's age at presentation may all be factors that relate to clinical management, but they do not imply specific consequences with respect to long-term outcome