pulmonary stenosis

Imagine the right side of the heart trying to push blood out through a partly jammed gate on its way to the lungs. In pulmonary stenosis the pulmonary valve — the exit from the right ventricle into the pulmonary artery — is narrowed, so the right ventricle must work harder to send blood toward the lungs for oxygenation.

To overcome the obstruction the right ventricle thickens its wall. Mild stenosis often causes no symptoms and may be found only by hearing a murmur. More severe narrowing can cause breathlessness on exertion, fatigue, and in extreme cases signs of right heart strain; in children with a tight valve it can be a cause of cyanosis when associated with other defects.

Pulmonary stenosis is most often congenital — present from birth, sometimes as an isolated finding and sometimes as part of a syndrome or a complex defect such as tetralogy of Fallot. It is much less commonly acquired. The diagnosis is made on echocardiography, and significant narrowing is frequently treated very effectively by balloon valvuloplasty, which stretches the valve open through a catheter.

Because most cases are congenital, pulmonary stenosis is usually managed within congenital and pediatric cardiology pathways; this is a general description only.