Stenosis of the Pulmonary Arteries: Evolution and Hemodynamic Effects

¹ Pediatric Cardiologist, Cardiac Laboratory, University of Lausanne

The evolution of stenosis of the pulmonary arteries may be enhanced by congenital heart disease leading to increased or decreased pulmonary blood flow. A third possibility is that an intrapulmonary right-to-left shunt through a vascular malformation hinders normal maturation of the pulmonary vascular bed. This evolution is illustrated by an example of severe stenosis of the pulmonary arteries occurring with pulmonary arteriovenous fistula. In most patients with isolated bilateral stenosis of the pulmonary arteries there is no significant increase in right ventricular pressure with age. A discrepancy between the increase in cardiac output and growth of the stenotic orifice in children may however aggravate it. Although the hemodynamic effect of bilateral stenosis of the pulmonary arteries is greater on the pressures than on the morphology of the pulmonary circulation, angiocardiographic diagnosis is usually possible. Pressure measurements show a gradient across and an abnormal pulse contour proximal to the stenosis.