Aortic stenosis and severe mitral regurgitation in the fetus resulting in giant left atrium and hydrops: Pathophysiology, outcomes, and preliminary experience with pre-natal cardiac intervention

Objectives The objective of this article is to review anatomic, physiologic, and clinical features of fetuses and neonates with severe mitral regurgitation (MR) in conjunction with aortic stenosis (AS) and left ventricular (LV) and left atrial (LA) dilation and to present preliminary results of pre-natal intervention for this condition. Background Severe fetal valvar AS with an abnormal mitral valve (MV) and MR can lead to left heart dilation, with consequent compression of the right ventricle (RV); hydrops and low cardiac output are often associated. Methods This is a retrospective review of fetuses diagnosed with AS, severe MR, and LA dilation (2002 to 2009) and neonates with the same combination of abnormalities (1988 to 2009). Results Fourteen fetuses and 7 neonates were investigated. Eleven fetuses had severe hydrops; all had polyhydramnios and a structurally abnormal MV, abnormal MV inflow pattern, restrictive/intact atrial septum, retrograde flow in the transverse aortic arch, and compression of the right heart. The mean indexed RV output was 326 ± 160 ml/kg/min, lower than the normal average fetal combined ventricular output of 550 ± 150 ml/kg/min. Ten fetuses underwent pre-natal cardiac intervention: aortic valvuloplasty (n = 8) and/or atrial septal dilation/stenting (n = 5). Seven of these, and 11 overall, were live born. Nine patients died (median age 6 days), and 2 patients are currently alive. All 7 patients diagnosed in the neonatal period died (median age 1 day). Conclusions Aortic stenosis associated with significant MR in the fetus can cause severe LA and LV enlargement, leading to low cardiac output and hydrops. Despite the potential advantages of early pre-natal diagnosis and both fetal and neonatal interventions, this rare complex of anomalies carries a poor prognosis.