0934 Hypoplastic left heart syndrome – UK review

Hypoplastic left heart syndrome is rare - ~2-3% of all congenital heart diseases, occurring in ~2/10000 live births. Untreated it is fatal in ~95% of cases and would be responsible for 25-40% of all neonatal cardiac deaths. Intervention options are transplantation and ‘staged functionally univentricular palliations.’ While non-transplant survival figures are given as ~65% at 5 years of age and 55% at 10 years, these statistics might be optimistic given that UK expected incidence is 200-260 per annum but a UK census of congenital heart disease in the mid-1990’s showed only 228 cases registered over a period of three years. There do not appear to be ethnic or geographic differences and it is slightly more common in males. No specific gene has been found to be responsible for the condition although recurrences in families occur and if two children have been affected then the risk is 25% going forward, and up to 12% of cases may occur with conditions such as Turner’s syndrome, trisomies 13 and 18, and terminal 11q deletion. Most paediatricians will have berated themselves for ‘missing’ the diagnosis but this should be seen in the context of adequate ductal and atrial shunting at birth that mask the underlying problem. Many cases are diagnosed at autopsy after collapse and death at home and in fact a large population-based study showed that 78% of cases are only diagnosed after hospital discharge. More than two-thirds of cases may be detected antenatally and in spite of surgical treatments being available, because of the high morbidity and mortality, termination should be offered as an option. For families that opt for more than ‘comfort care’ pre-operative postnatal management is directed at maintaining ductal patency, possibly decompressing the left atrium, and supporting cardiac function. The Norwood follows in neonates, creating a univentricular circulation, then stage II at 6-8 months and stage III between 18 months and 5 years of age, the latter procedures creating a passive flow of venous blood through the lungs. Follow-up studies into childhood and adolescence show normal IQ but reduced quality of life. Long-term (uni)ventricular function is still unknown, the expectation being that it will deteriorate over time.

Read more:
Lancet 2009; 374: 551-64
Acta Paediatr 2007; 96: 53-7
Pediatr Cardiol 2007: 28: 79-87