Flow characteristics in infants with hypoplastic left heart syndrome: an echocardiographic study

From July 1992 to January 1993, a total of 5 cases of hypoplastic left heart syndrome were diagnosed by echocardiograms and confirmed by available angiographic, surgical or autopsy results. The flow dynamics disclosed by spectrum display in the aortic root and patent ductus arteriosus (PDA), in systole, were: (1) antegrade in the ascending aorta and descending aorta (below PDA), and retrograde in the transverse aorta, and (2) right-to-left shunt in the PDA. While in diastole, there were (1) antegrade in the transverse aorta, and retrograde in the ascending aorta and descending aorta (below PDA), and (2) left-to-right shunt in the PDA. No ventriculocoronary fistulas were identified. With both the characteristic flow pattern and the extremely narrow diameters of the ascending aorta in hypoplastic left heart syndrome, we can differentiate it from those heart diseases associated with secondary hypoplastic left heart due to total anomalous pulmonary venous connection or congenital pulmonary venous stenosis. Both help us understand better the hemodynamics and pathophysiology of hypoplastic left heart syndrome in these patients.