Recognition of Left Atrial Aneurysm by Fetal Echocardiography

A fetus was noted to have a mediastinal mass on prenatal ultrasound. Fetal echocardiography at 26 weeks of gestation demonstrated a large cystic structure adjacent to the left atrium and left ventricle (Figure 1⇓). The baby was born full term. Echocardiography revealed a large, thin-walled aneurysm (3×3 cm) lateral to the left atrium and communicating with it through an orifice posterior to the base of the left atrial appendage. As determined by MRI, this aneurysm extended from the transverse aortic arch to the cardiac apex (Figure 2 …