Discussion:
Our case illustrates a type B DCLV and is the first case in which antenatal images are available.
Differential diagnosis includes diverticulum or aneurysm of the left ventricle. In the former the outpouching has 3 layers, contracts during systole and has a narrow connection with the LV. In the later, connection with the LV is large and the cavity does not contract or is dyskinetic [2]. In our patient the outpouching had a wide connection to the LV from which it was separated from muscle bundles but had initially a normal contractility characterizing DCLV.
Several authors consider that type B DCLV is a benign condition frequently found incidentally [1;3-6]. It can also be complicated by dysrhythmias [7] or by left ventricular dysfunction as in our case [8]. It is likely that the size of the AC influences the long-term tolerance of the anomaly since a large AC causes chronic volume overload of the left ventricle that could lead to LV dysfunction. Indeed, in a report of more than 800 cases of left ventricular aneurysm or diverticulum Ohlow et al. noticed that LV dysfunction occurred in the largest outpouchings [9].
Thus, type B DCLV is an exceedingly rare congenital heart malformation that can be diagnosed during fetal life. Although most of reported cases have a benign outcome and are asymptomatic, its prognosis probably depends on the size of the AC, large AC could result in chronic LV overload and dysfunction. Prenatal family counselling should mention this possible evolution.