SUMMARY The hearts of 291 babies with congenital heart disease who died before the age of one were examined systematically by sequential segmental analysis to determine the lesions that were present. There was an abnormal connection between the cardiac segments in one third of cases. Patient ductus arteriosus, which is usually a common defect, was not an important finding at necropsy, whereas common arterial trunk (a rare defect) was found in 10%. The clinical and necropsy incidence of complete transposition was similar to that reported in earlier studies. The incidence of some lesions present at necropsy (for example Fallot's tetralogy) has altered over the past 10 years. A decline in the frequency with which a lesion is detected at necropsy may indicate advances in treatment or differences in classification. The presence of additional lesions influences the prognosis and subcategorisation within the major defect groupings gave some insight into the cause of death in many of the cases.In the West congenital heart disease is the most common cardiac condition of childhood. It may affect as many as 2% of livebirths'2 and many babies with congenital heart disease die within the first few weeks of life. More die, with or without surgical intervention, before the end of their first year.More specific classification of these cardiac lesions depends on a systematic approach to the diagnosis of congenital heart malformations, such as that proposed by Van Praagh.3 With some modifications4 we have used this approach to analyse a large series of necropsy cases aged one year and younger collected over the past ten years at this hospital.
Patients and methodsWe studied 291 hearts from patients who died within the first year of life. These hearts comprised 72% of the 403 The specimens were divided into two age groups-those aged < 4 weeks and those aged from 4 weeks to one year.We systematically examined each heart by a sequential segmental approach4 and noted any abnormal connections or arrangements of the cardiac segments. We then ascribed a primary diagnosis to each heart. Hearts which showed an absent left atrioventricular connection, with a main chamber of right ventricular morphology (classical mitral atresia) and hearts with an imperforate mitral valve were grouped with specimens having aortic atresia. This was so that our series could be compared with clinical series in which these conditions were combined. In hearts with multiple lesions the primary lesion was the one regarded as being of greatest morphological importance. In some cases these primary lesions were further categorised by subgroup.The incidence of each lesion in both age groups was calculated as a percentage. This necropsy incidence was compared with the clinical incidence at the Brompton Hospital,5 and both these sets of data were then compared with data from other centres.67
Results