History, diagnosis, surgery and epidemiology of pulmonary stenosis in Malta.

The Maltese population constitutes an ideal location for epidemiological and historical studies dealing with congenital heart malformations. Pulmonary stenosis was studied retrospectively from 1943 to 1994. A sharp, significant decline in age at diagnosis was found, which predates the introduction of echocardiography. All defects are now diagnosed by echocardiography, which has resulted in an increased prevalence at birth of this lesion, particularly of pulmonary stenosis not requiring intervention. The prevalence at birth of pulmonary stenosis from 1990 to 1994 was 1.65/1000 live births (95% CI: 1.21-2.24), with 1.11/1000 mild lesions (95% CI: 0.76-1.62) and 0.54/1000 lesions requiring intervention (95% CI: 0.31-0.92). The prevalence at birth overall was significantly higher than that reported in recent studies with similar methodologies due to the higher pickup of milder variants of pulmonary stenosis by echocardiography. Significantly more pulmonary stenosis was found in females than in males.