A 5 year old boy was referred for evaluation of a heart murmur. Slight stenosis of the left pulmonary artery and an abnormal connection between the left pulmonary vein and the innominate vein was found on transthoracic echocardiography. MRI confirmed a dilated levoatriocardinal vein of 9 mm between the left superior pulmonary vein and the dilated innominate vein. The left pulmonary veins were normally connected to the left atrium (see fig). The left pulmonary artery was mildly compressed by the levoatriocardinal vein. Because of a left to right shunt (Q_p/Q_s 1.4), the right sided heart was slightly enlarged but no other cardiovascular malformation was found. A 12–10 PDA Amplatzer device was used to completely occlude the levoatriocardinal vein. A levoatriocardinal vein is a pulmonary to systemic connection that provides a mechanism for decompression of the pulmonary venous blood, usually to bypass a severe left sided obstruction. Magnetic resonance imaging, particularly MR angiography, is the non-invasive procedure of choice to demonstrate this extracardiac anomaly. This case is original because the left heart is completely normal. Surgery or interventional cardiac catheterisation are both reasonable management options for this rare anomaly.

Coronal spin-echo magnetic resonance image (left panel), coronal mutliplanar reconstruction (centre panel), and posterior view of the volume rendering (right panel) of a gadolinium-enhanced three dimensional MR angiography. The levoatriocardinal vein (arrow), connecting the left superior pulmonary vein (LSPV) to the innominate vein (In V) is clearly demonstrated. Note the normal connection of all pulmonary veins to the left atrium (LA). PA = pulmonary arteries; SVC = superior vena cava; RSPV = right superior pulmonary vein; LIPV = left inferior pulmonary vein.