Supra-cardiac total anomalous pulmonary venous return (TAPVR)

CT scout

The scout shows moderate cardiomegaly with widened superior mediastinum and increased pulmonary vascularity.

Heart

• situs solitus, the cardiac apex to the left
• atrio-ventricular and ventriculoarterial concordance
• great vessel relationship: normal
• small ostium secundum ASD is noted
• intact IVS
• moderate cardiomegaly is noted with moderate right-sided dilatation
• no pericardial effusion

Aorta

• the ascending aorta arises from the left ventricle and measures about 0.86 cm at its maximum diameter (at the level of the main pulmonary artery)
• left sided aortic arch that gives rise to three orderly branches (the left subclavian, the left common carotid, and the brachiocephalic arteries) with normal distribution of its branches. The aortic isthmus measures about 0.65 cm at the level of left subclavian artery’s origin.
• the descending aorta is seen running in the left paravertebral space.  Normal origin and distribution of the coronary arteries.
• no evidence of thoracic or abdominal coarctation
• no PDA

Pulmonary arteries & veins

• antegrade continuity between the right ventricle and main pulmonary artery.
• confluent mildly dilated main pulmonary artery and its both branches.
  • the MPA is uniform in caliber that measures about 1.52cm in diameter
  • the LPA shows mild stenosis that measures about 0.82cm in diameter, while distally it measures about 1.00cm in diameter
  • the RPA is uniform in caliber that measures about 0.94cm in diameter
• supra-cardiac total anomalous pulmonary venous drainage: the four pulmonary veins are draining into a confluent chamber that measures about 1.1 X 3.7 cm behind the left atrium which opens into a vertical vein that measures about 1.03 cm in diameter and about 2.69 cm in length which opens into the left innominate vein which opens into the markedly dilated SVC that measures about 1.94 cm in diameter. No evidence of pulmonary vein stenosis

Venae cava & innominate veins

• normal course of the innominate veins, SVC and the visualized segment of IVC
• no left SVC
• SVC receives azygos vein

Lungs

• congested both lung fields
• no pleural sac collections

Supra-cardiac total anomalous pulmonary venous drainage with the four pulmonary veins are draining into a confluent chamber behind the left atrium which opens into a vertical vein that opens into the left innominate vein which opens into the markedly dilated superior vena cava (SVC). 

Supracardiac type is the commonest type (50%) of the TAPVR and usually non-obstructive. Plain radiograph typically shows snowman heart (figure-of-eight heart)  with the supracardiac shadow is attributed to dilated right SVC, vertical vein, and brachiocephalic vein.

Total anomalous pulmonary venous drainage is a left to right shunt and patent foramen ovale or ASD is invariably present.  

The case is courtesy of Dr. Mohammad A. ElBeialy, and Dr. Heba Kamal.