Discussion

Congenital ventricular aneurysms are protrusions originating from the free wall of the ventricles or the apex. Aneurysms are mostly compared with diverticula, and the distinction between them is not clear so some authors have collected them under the term “outpouching.” ^{Reference Williams, Collardey and Tradwell1} Congenital ventricular aneurysm and diverticula were first described in 1816 in Germany. ^{Reference Kreysig2} Since then, it is difficult to obtain true epidemiological data because there are generally case reports in the literature. In an autopsy study of 12.924 cases in children, the prevalence was reported as 0.02%. ^{Reference Albrecht3} It was first described as antenatal in 1990 in a fetus with ventricular extrasystole at 32 weeks of gestation. ^{Reference Gembruch, Steil and Redel4} In later studies, the prevalence was determined as 0.5 per 100.000 live births. ^{Reference Gonc alves, Simms and Jeanty5} We performed 16,250 fetal echocardiography between 2007 and 2020, and three cases of ventricular outpouching were detected, including one of them we reported here. The other case with left ventricular aneurysm was previously reported. ^{Reference Demir, Ozbarlas and Gocen6}

Congenital ventricular aneurysm and diverticula are both more common in the left ventricle. While congenital ventricular aneurysms are most frequently located in the apex and perivalvular area of the left ventricle (mostly the submitral region), diverticula are more frequently located in the apex of the left ventricle. ^{Reference Ohlow, Secknus and Geller7} The number of cases reported to be located in the right ventricle is much less, and the frequency of localisation in any region of the right ventricle has not been reported. Williams et al. reported three cases of right ventricular outpouching, and in their study that included fourteen right ventricular outpouching cases previously published, they reported that nine cases were apical and eight cases were non-apical. ^{Reference Williams, Collardey and Tradwell1} However, Zheng et al. reported that right ventricular outpouchings are more frequently located in non-apical regions, especially in the basal segment of the right ventricle. ^{Reference Zheng, Sun and Liu8}

It is important to differentiate aneurysm or diverticulum in order to plan its follow-up and predict the prognosis. Aneurysms have a wide necked connection with the ventricle and have a thin outer wall. The aneurysm wall does not contain all the wall layers of the ventricle, and the myocardial tissue has been replaced by fibrous tissue. Therefore, the aneurysm wall may be hypokinetic, akinetic, or act paradoxically with the ventricle during ventricular systole. The connection of the diverticula with the ventricle occurs through a narrow neck. Since all three ventricular layers are present in the diverticulum wall, the wall does not appear thin and its movement is normal.

Congenital ventricular outpouching can be seen with other cardiac, vascular, and extracardiac defects. Ventricular septal defect, coronary anomalies, atrial septal defect, pulmonary hypoplasia, aortic coarctation, and persistent left superior caval vein were the most common accompanying cardiac and vascular abnormalities. ^{Reference Ohlow, von Korn and Lauer9} The most common extracardiac anomalies are midline defects such as diaphragmatic defects and sternal abnormalities. It was observed that the frequency of extracardiac defects accompanying diverticula was higher. ^{Reference Ohlow, von Korn and Lauer9}

Congenital ventricular outpouching is usually asymptomatic. However, large aneurysms and diverticula can cause heart failure due to the volume overload. This volume load is less tolerated in the fetal and neonatal period. Therefore, heart failure, pericardial effusion, and associated mediastinal shift, hydrops can be seen in younger ages, including the antenatal period. ^{Reference Ohlow, von Korn and Lauer9} Cases that pericardiocentesis performed during antenatal period with congenital ventricular outpouching have been reported. ^{Reference Gardiner, Wimalasundera and Pasquini10} Pericardial effusion is more common with right ventricular aneurysms. Williams et al. reported that pericardial effusion is more common in apical right ventricular aneurysms than non-apical right ventricular aneurysms. ^{Reference Williams, Collardey and Tradwell1} At the fetal period, different clinical findings such as arrhythmia, ventricular dysfunction, and valve regurgitation are more common in non-apical right ventricular aneurysms rather than pericardial effusion, and they can be symptomatic at birth, but it has been reported that they are generally asymptomatic during follow-up. ^{Reference Williams, Collardey and Tradwell1} Embolic events are more common in aneurysms and attributed to the aneurysm wall being akinetic or hypokinetic. Oral anticoagulants are recommended for patients with embolic events. Our case was asymptomatic in the prenatal and postnatal period.