Total anomalous pulmonary venous connection to the left vertical vein. A plain-film sign useful in early diagnosis.

Total anomalous pulmonary venous connection to the left vertical vein often may be recognized on the plain postero-anterior chest radiograph by the characteristic supracardiac shadow. This "snowman sign" is useful in older patients but rarely is apparent in infancy. In such young patients the authors have discovered a density anterior to the trachea on the lateral chest radiograph. This finding is present prior to the appearance of the snowman sign and should prove useful in the early diagnosis of this anomaly, facilitating prompt, appropriate treatment. Five representative cases are tabulated and developmental and clinical aspects are reviewed.