Prenatal detection of fetal left ventricular aneurysm is rare condition defined by a unilobulated or multilobulated bulging of a ventricular wall segment. The clinical profile, natural course, and treatment remain unclear because these malformations are rare. In view of their infrequency, it would be interesting to report cases in order to have more data concerning the diagnosis, the prognosis and the management.

We present a case of left ventricular aneurysm with a hydrops foetalis diagnosed at 21 weeks’ gestation in a 23-year-old primiparous woman who was referred for routine screening ultrasonography.

A fetal echocardiogram showed an abnormal four-chambers view with a large cystic lesion on the anterolateral wall of the left ventricle. We found a severe left ventricular dysfunction with a severe mitral regurgitation with an hydrops foetalis with a pericardial effusion, large volume septate ascite and a bilateral pleural effusion. Fetal MRI, in T2 Trufi sequences (axial, coronal and sagittal sections), shows a large segment of the apical left ventricular wall that exhibited a thin-walled outpouching with a wide communication to the left ventricular cavity (Figure 1).

Congenital LV aneurysms (LVA) are rare and poorly understood. Twenty-six reported cases were published until 2014 (Figure 2). The differential diagnosis is congenital left ventricular diverticula. The prognosis of congenital left ventricular aneurysms is quite variable, depending on size, growth over time, the presence or absence of compression of the fetal lung and signs of cardiac failure.