Abstract
Congenital pulmonary valve stenosis has been associated with the development of massive pulmonary arterial (PA) dilatation. Over time, this dilatation may distort surrounding structures and lead to compression of the left main coronary artery (LMCA) or the left mainstem bronchus. In this report, we describe a patient with a history of chronic thromboembolic pulmonary hypertension (CTEPH) and congenital pulmonic stenosis with massive PA dilatation. He develops exertional chest pain, presenting an unusual differential diagnosis. Novel diagnostic testing was performed to help narrow the differential diagnosis, and the patient responded well to pulmonary vasodilator treatment for progressive pulmonary hypertension.