Aberrant systemic arterial supply to the left lung with congestive heart failure.

A six-month-old girl with an aberrant systemic arterial supply from the descending thoracic aorta to the left lower lobe had congestive heart failure. Although the pulmonary parenchyma was normal, there was an absence of normal pulmonary arterial supply to the left lower lobe. Main pulmonary arterial and aortic cineangiograms led to the correct diagnosis. Left lower lobectomy was performed and resulted in clinical and hemodynamic improvement.