Hypoplastic left heart syndrome: current treatment options and outcome

Abstract

Hypoplastic left heart syndrome (HLHS) represents a spectrum of lesions having in common hypoplasia of the left ventricle, in association with aortic valve atresia or stenosis, mitral valve atresia or stenosis and hypoplasia of the aortic arch. l The precise aetiology of this lesion is unknown. Maintenance of systemic circulation depends upon pulmonary venous blood reaching the right atrium through an interatrial communication, which is often restrictive. Common mixing of oxygenated and deoxygenated blood within the right atrium and ventricle occurs, and this is then distributed both to the lungs (via the pulmonary arteries) and to the systemic circulation through the arterial duct. Coarctation of the aorta adjacent to the ductal insertion is common, and is due to extension of ductal tissue into the aorta. As the left ventricle does not contribute to cardiac output, perfusion of the coronary arteries and myocardium is dependent upon retrograde flow into the ascending aorta via the arterial duct.