Idiopathic pulmonary arterial hypertension with coexisting CHD.

Sinus venosus atrial septal defect can result in an increase in pulmonary blood flow and vascular resistance, leading to pulmonary hypertension. Rarely, the degree of pulmonary hypertension is out of proportion to the degree of intra-cardiac shunting. This case outlines the differences between pulmonary hypertension secondary to CHD and idiopathic pulmonary hypertension, and illustrates the investigation and management strategy used in a patient with features of both.