Obstructed right pulmonary venous drainage and ipsilateral lung hypoplasia.

A case of right lung hypoplasia and dyspnea, presented at our institution for cardiac evaluation, is described. Clinical evaluation and instrumental findings of normally connected but completely obstructed right pulmonary venous drainage have led us to diagnose an exceptional variant of subtotal cor triatriatum. Differential diagnosis was mainly carried out between pulmonary venous anomalies and drainage obstructions. Symptom relief was obtained with surgical excision of the atrial dividing membrane.