Fetal Cardiac Diverticulum
A fetus at 20 weeks of gestation was noted to have a pericardial effusion. Fetal echocardiography (Figure 1) showed a communication between the apex of the right ventricle and an intrapericardial thin-walled expansion. Over the following several weeks, the pericardial effusion resolved. At birth, the baby had an intrapericardial fibrous diverticulum opening into the right ventricle (Figure 2). Because of the risk of rupture, the diverticulum was surgically plicated. The baby is well.
Congenital cardiac diverticula are rare. The present observation suggests that some diverticula may result from spontaneous myocardial rupture, with sealing of the perforation before fatal tamponade occurs. After absorption of the blood from the pericardial cavity, only the fibrosed “containment cyst” would remain, with a communication into the heart at the site of perforation.