Abstract
Abnormal pulmonary venous flow patterns on fetal echocardiography and a
nutmeg lung pattern on fetal magnetic resonance imaging are seen in
patients with pulmonary venous stenosis. The association between these
findings and the degree of pulmonary venous stenosis remains unknown. We
report an extremely rare case of a fetus diagnosed with hypoplastic left
heart syndrome complicated by an absent atrial septum and supracardiac
total anomalous pulmonary venous connection with left pulmonary venous
congestion. This case suggests that compared to non-pulsatile continuous
pulmonary venous flow, the nutmeg lung pattern can only be observed with
severe pulmonary congestion and advanced pulmonary lymphangiectasia.
Keywords: case report, hypoplastic left heart syndrome, absent
atrial septum, supracardiac total anomalous pulmonary venous connection
Introduction
Hypoplastic left heart syndrome is rarely complicated by the absence of
an atrial septum.1 In addition, the incidence of
complications of total anomalous pulmonary venous connection (TAPVC) in
patients with hypoplastic left heart syndrome is low (2.3%), and the
prognosis is poor. The prognosis may even be poorer if the condition is
further complicated by pulmonary venous stenosis.2,3
The nutmeg lung pattern refers to the heterogeneous appearance of the
lung parenchyma, identified as the presence of subtle T2-hyperintense
branching tubular structures that emanate from the hila on fetal
magnetic resonance imaging (MRI). Previous studies have shown that this
pattern suggests the presence of pulmonary lymphangiectasia and, in
relation to congenital heart disease, may be considered indicative of
secondary lymphangiectasia caused by pulmonary venous
congestion.4,5 However, few studies have investigated
this condition. The association of the nutmeg lung pattern with the
degree of pulmonary congestion and prognosis remains unclear. This study
reports an extremely rare case of hypoplastic left heart syndrome
complicated by an absent atrial septum and a mixed form of supracardiac
TAPVC accompanied by pulmonary venous stenosis. This article discusses
fetal echocardiographic and MRI findings as well as the postnatal course
of the neonate.