The case of the missing pulmonary vein: A focused update on anomalous pulmonary venous connection in congenital cardiovascular disease.

Partial anomalous pulmonary venous connection is defined by one or more of the pulmonary veins draining to the heart into a location other than the left atrium. Depending on the location of the anomalous venous connection, they can be categorized as supracardiac, infracardiac, cardiac, and mixed types. In some cases, there is no hemodynamic consequence; in others, it can result in tricuspid regurgitation, right heart dilation, and pulmonary hypertension. Frequently, the reason for referral can be asymptomatic right heart dilation of unknown significance. Diagnosis is often difficult by transthoracic echocardiogram unless there is a high index of suspicion, and the appropriate views are obtained. Cardiac CT (computed tomography) or cardiac MRI (magnetic resonance imaging) can provide more precise anatomic detail as needed. The current article reviews the etiology and pathophysiology of partial anomalous pulmonary venous connection, and also reviews the current knowledge on their treatment.