Spectrum of congenital heart disease in Malta. An excess of lesions causing right ventricular outflow tract obstruction in a population-base study

Aims To quantify birth prevalence and spectrum of congenital heartdisease in the Island population of Malta, and compare theserates with previous studies. Methods All patients diagnosed as having congenital heart disease byechocardiography, cardiac catheteriz-ation, surgery or post-mortemby 1 year of age between 1990–1994 were included. Therewere 231 cases of live born congenital heart disease with abirth prevalence of 8·8/1000 live births. The commonestlesions were ven-tricular septal defect, pulmonary stenosisand tetralogy of Fallot. The rates of individual lesions werecompared with two recent epidemiological studies with similarmethodologies. Results Although the overall birth prevalence of congenital heart diseasewas similar in three studies, significantly higher rates ofpulmonary stenosis, tetralogy of Fallot and double outlet rightventricle were found in Malta, all of which predispose to rightventricular outflow tract obstruction. In contrast, there werelower rates of lesions causing left ventricular outflow tractobstruction. A higher rate of ventricular septal defect wasalso found. The Maltese gene pool may contain an inherent predispositiontowards lesions causing right ventricular outflow tract obstruction.