Study of Pulmonary Arterial Pressures and Histopathological Changes in Patients Having Congenital Heart Defects with Left-to-Right Shunt.

Pulmonary arterial hypertension, a common complication in patients with congenital heart defects with left-to-right shunt who present late is one of the principal determinants of the clinical manifestations, the course and the feasibility of surgical repair. The objective is to study the pulmonary arterial pressures and the pulmonary histopathological changes in patients having congenital heart defects with left-to-right shunt. A total of 20 consecutive patients having congenital heart defects with left-to- right shunt who underwent surgical correction were studied. Intra-operative mean pulmonary arterial pressures were measured before and after surgical correction. Lung biopsy was taken to study the histopathological changes of lung parenchyma and vasculature. All patients, irrespective of age at the time of surgical repair and the type and size of the cardiac defect had raised mean pulmonary arterial pressures that were decreased significantly immediately after surgical correction. Pulmonary parenchymal changes and vascular changes were noted in 18 and 9 patients respectively. The pulmonary vascular changes were significantly correlated with the mean pulmonary arterial pressures. The pulmonary parenchymal changes though were a consistent finding; not significantly correlated with the mean pulmonary arterial pressures.