Case of Anomalous Right Superior Vena Cava
A 36-year-old black woman with no significant medical history presented with severe headache, vertigo, nausea, and vomiting. Initial evaluation was significant for ataxia and nystagmus. A computed tomography scan of the head was performed and showed a left posteromedial cerebellar infarct (presumed to be secondary to a transient embolic occlusion of the left posterior inferior cerebellar artery). Magnetic resonance angiography of the head and neck vessels was unremarkable. Further workup included a transthoracic echocardiogram, which was significant for a dilated coronary sinus suggestive of a persistent left superior vena cava (SVC). Agitated saline contrast injection into the left arm resulted in opacification of the coronary sinus (Figure 1A, arrow), as well as the right atrium and ventricle (Figure 1B). Interestingly, contrast injection into the right arm failed to opacify the coronary sinus (Figure 2A, arrow) but completely opacified the left atrium and ventricle (Figure 2B and Movie). Transesophageal echocardiography showed no evidence of patent foramen ovale and confirmed the previous findings, suggesting right-sided anomalous venous return. A dynamic gadolinium-enhanced magnetic resonance venogram through synchronous injection in both arms was performed (repetition time/echo time 1/1.3, Siemens Symphony, Erlangen Germany). Initial images demonstrated a persistent left SVC (Figure 3A, arrow) entering the right atrium through the coronary sinus (Figure 3A, arrowhead). Sequential images revealed right SVC flow (Figure 3B, arrow) entering into the left atrium (Figure 3B, arrowhead). These images confirm the diagnosis of anomalous venous drainage of the right SVC into the left atrium resulting in right-to-left shunt. Although the patient was not cyanotic, her blood gas levels revealed mild hypoxemia, and the patient reported that she had avoided strenuous exercise since childhood because of easy fatigability. The patient was started on oral anticoagulation, and an uneventful surgical repair was performed 8 weeks later.
The online-only Data Supplement, which includes a movie, is available with this article at http://circ.ahajournals.org/cgi/content/full/114/15/e532/DC1.