Salwa M. Gendi, MD & Patricia O’Dierno, MD
Anomalous drainage of the IVC into the left atrium is a very rare congenital anomaly of the heart. In our case report, we have a newborn female who had continued hypoxia after birth despite multiple interventions. An echocardiogram showed a bilateral SVC, with the right SVC and IVC draining into the right atrium and the left SVC draining directly into the left atrium, an absent innominate vein between the two SVCs, a small PFO, and an unroofed coronary sinus. The patient was discharged home with oxygen saturations ranging from 75-85%. During surgical correction at four months of age, it was found that her IVC entered the diaphragm at a normal position, but drained into the left atrium due to the malformation of the atrial septum. The atrial septum was reconstructed to redirect the IVC to drain into the right atrium. After surgical correction, she had normal oxygen saturations and was discharged home.
FIGURE 1 Apical 4 chamber view. No abnormality detected.
The IVC is normally formed by the contribution of five venous systems and carries blood into the right atrium. In our case, the malposition of the septum primum caused the IVC to drain into the left atrium. When the septum secundum is absent, it can cause the septum primum to be displaced in either direction. This can cause the pulmonary veins to drain into the opposite atria, and can cause the IVC to drain in the opposite atrium as well. Many times, surgical treatment is warranted. There are three types of repairs. If there is AV concordance, a new septum can be constructed so that the systemic and pulmonary veins drain into the corresponding atria. If there is AV discordance with well-developed ventricles, the pulmonary and systemic veins can be rerouted to drain into the corresponding ventricles. If a biventricular repair cannot be achieved, it is generally due to a more serious congenital malformation. In the case of our patient, her septum was able to be reconstructed to cause her IVC to drain into her right atrium. Partial or complete drainage of the IVC into the LA can cause cyanosis, polycythemia, brain abscess and paradoxical emboli due to the right-to-left shunting.
To read the full article, please go to the January 2020 Issue of CCT.