Discussion

Congenital left ventricular aneurysm and left ventricular diverticulum are rare cardiac congenital malformations, first described in 1816 in Germany. ^{Reference Kreysig, Theirl, Abteilung and Kreysig1} They appear to be developmental anomalies that arise during the 4^th embryonic week of gestation. ^{Reference Van Mierop and Kutschke2} Most cases of left ventricular aneurysm/left ventricular diverticulum are asymptomatic but carry a risk of systemic embolisation, congestive heart failure, ventricular wall rupture, ventricular tachycardia or sudden cardiac death. ^{Reference Ohlow3} Left ventricular aneurysm is a ventricular akinetic or dyskinetic protuberance of fibrous tissue with no organised myocardium. On the other hand, congenital left ventricular diverticulum is an outpouching from a ventricle which contracts synchronously with that chamber and histologically contains all three layers of the ventricular wall (endocardium, myocardium, and pericardium). ^{Reference Hamaoka, Onaka, Tanaka and Onouchi4}

A retrospective study of 12,924 consecutive autopsies in children found 750 (5.8%) cases with congenital cardiac defects and 3 cases (0.02 %) with left ventricular diverticulum. ^{Reference Albrecht5} Congenital left ventricular aneurysm and left ventricular diverticulum are associated with other congenital anomalies including cardiac, vascular, or extracardiac anomalies. The prevalence of associated anomalies is markedly higher in patients with left ventricular diverticulum (34%) compared to left ventricular aneurysm (11%) suggesting a different aetiology and pathogenesis during embryonic development. ^{Reference Ohlow, von Korn and Lauer6}

A universal classification of left ventricular outpouching anomalies is not yet established. In 1961, Loogen et al. proposed a two-group classification where one group included pulsating palpable masses below the diaphragm and the other included masses above the diaphragm. ^{Reference Loogen, Rippert and Vieten7} A more recent approach classified cases of congenital left ventricular outpouchings according to left ventricular geometry, wall thickness, and motion. ^{Reference Rad, Awad and Hijaz8} Accordingly, our case would be classified as type IIc, which carries a poor prognosis if left untreated.

In the perinatal period, left ventricular diverticulum and left ventricular aneurysm are mostly discovered on echocardiography. Asymptomatic smaller lesions are diagnosed incidentally later in life. ^{Reference Ohlow, von Korn and Lauer6} Our case was diagnosed by routine fetal echocardiography. Shuplock et al. described 86 cases of prenatally diagnosed congenital left ventricular outpouchings. ^{Reference Shuplock, Kavanaugh-McHugh and Parra9} Pericardial effusions (44%) and ventricular dysfunction (17%) were the most common cardiac findings. Mortality rate was 17%, with the majority occurring prenatally. Factors associated with mortality included an outpouching located on the left ventricle, hydrops fetalis, pericardial effusion, and an earlier gestational age at diagnosis. Of those who survived to delivery, 57% remained asymptomatic without intervention, 15% regressed, and an additional 15% resolved. ^{Reference Shuplock, Kavanaugh-McHugh and Parra9} Our patient did not have any arrhythmias but developed respiratory distress and low systolic blood pressure that required respiratory and inotropic support that could be related to the severely depressed left ventricular systolic function with giant dyskinetic aneurysm.

Treatment modalities of left ventricular aneurysm and left ventricular diverticulum are determined by the clinical presentation and associated findings of the patient. Conservative management may be sufficient in asymptomatic cases. Surgical resection is needed in symptomatic cases with associated cardiac anomalies. The first successful resection of an apical left ventricular diverticulum in a newborn was documented in 1944. ^{Reference Roessler10} Surgical technique depends on the type and extension of the outpouching and usually requires cardiopulmonary bypass, although up to 30% can be resected without extracorporal circulation. ^{Reference Ohlow, von Korn and Lauer6}

In our case, we proceeded with early surgical resection taking into consideration the high risk of rupture, thromboembolic complications, and congestive heart failure.

In conclusion, congenital left ventricular aneurysm and left ventricular diverticulum are rare congenital cardiac defects that can be diagnosed prenatally. Early surgical resection can be associated with favourable outcomes in large symptomatic cases.