A False Diagnosis of Hypoplastic Left Heart Syndrome in a Fetus

ABSTRACT

Typical hypoplastic left heart syndrome(HLHS) is a distinct pathologic entity with aortic atresia, mitral atresia, very hypoplastic or absent left ventricle and thread like ascending aorta. Occasionally, the lesser degree of hypoplasia is found and is called hypoplastic left heart complex(HLHC) by some authors. This HLHC is often associated with critical aortic stenosis. Fetal echocardiography has enabled us to observe human fetal heart in-utero and to diagnose congenital heart disease prenatally over the last 20 years. The diagnosis of HLHS in fetal echocardiography is based on 2-dimensional echocardio -graphic evidence of a diminutive ascending aorta, aortic atresia, mitral atresia or severe stenosis and a hypoplastic left ventricle. Abnormal flow direction through atrial septum or through isthmus greatly aids the diagnosis. This report shows a fetal case who showed hypoplastic left side chambers and retrograde isthmic flow and was diagnosed with hypoplastic left heart syndrome. After birth, although the baby had tachy-dyspnea for the first 3 weeks, she finally recovered without any intervention and showed catch up growth of left side chambers. This case illustrates the extreme difficulty of assessing left ventricle in a fetus.