Levoatriocardinal vein with partial anomalous venous return and a bidirectional shunt.

A 52-year-old woman with a history of systemic lupus erythematosus presented to our institution with nonhealing ulcers on her left lower extremity and toes. She had no cardiac symptoms, with a normal ECG and chest radiograph (Figures 1 and 2). As part of her evaluation she underwent a transesophageal echocardiogram to look for endocarditis, which demonstrated a right-to-left shunt with Valsalva that appeared to originate from the vicinity of the lateral aspect of the left atrium (Movie I in the online-only Data Supplement). There was also a vascular structure seen adjacent to the aorta that typically would represent a remnant of the cardinal vein, such as a persistent left superior vena cava. There were no findings of endocarditis. A magnetic resonance angiogram was performed to further evaluate the origin of the right-to-left shunt and demonstrated a levoatriocardinal vein that drained the left upper lobe pulmonary veins. This levoatriocardinal vein connected the left innominate vein with the left atrium via the left superior pulmonary vein (Figure 3). The flow in the levoatriocardinal vein was demonstrated to be primarily directed cephalad, creating a left-to-right shunt, as would be expected. However, cine phase contrast imaging demonstrated a reversal of flow in the levoatriocardinal vein after Valsalva (Figure 4). This was the source of the right-to-left shunt detected on transesophageal echo. Transthoracic echo confirmed the bidirectional flow in the levoatriocardinal vein (Figures 5 and 6, Movies II and III in the online-only Data Supplement). There were no findings of volume overload in the right heart because the left pulmonary veins were still connected to the left atrium, with only partial drainage of these veins into the innominate vein. Further clinical history revealed that the patient was having clusters of transient ischemic attacks, most recently after coughing spells during hospitalization for pneumonia while she had an intravenous line in her left arm. This raised the possibility of paradoxical embolism due to reversal of the shunt by severe coughing. This anomaly was determined to be treated best using percutaneous embolization of the levoatriocardinal vein. The