The Pulmonary artery or trunk is a blood vessel that takes blood from the heart to the lungs for oxygenation. Blood leaving the heart to the lung has low oxygen and therefore needs oxygen from the lungs to be able to satisfy the metabolic needs of the body.
Pulmonary stenosis is a congenital lesion that occurs when there is an obstruction to the flow of blood to the lungs from the heart either below the valves (subvalvular), at the level of the valves (valvular) or above the valves i.e the pulmonary trunk itself (supravalvular).
It may occur alone or along with other conditions like Tetralogy of Fallot, Noonan syndrome or Congenital Rubella Syndrome.
It accounts for 10% of all Congenital Heart Diseases.
Like other congenital heart diseases, pulmonary stenosis can be inherited (genetic). Smoking and alcohol intake during pregnancy, rubella infection during pregnancy and certain drug use during pregnancy can increase the risk of having a baby with pulmonary stenosis.
Obstruction to flow of blood from the right ventricle leads to increased pressure. As a compensatory mechanism to push more blood out, thickening of the right ventricle occurs.
Right ventricular emptying time is increased and therefore the cardiac output (amount of blood that leaves the heart to the body in one minute) is reduced. The severity of the condition is proportional to the degree of stenosis.
If there is an associated Atrial Septal Defect or patent foramen ovale, deoxygenated blood may move to the left side of the heart and will be pumped to the body.
SIGNS AND SYMPTOMS
Symptoms may include:
- Fatigue during exertion – they get tired after few minutes of suckling
- Sudden death
Signs the doctor may pick include:
- Cyanosis (bluish discolouration of the tongue, lips, hands and feet)
- Raised jugular venous pressure
- Visible heartbeats on the baby’s chest
- Ejection systolic murmur on auscultation
The doctor may request for chest X-ray, Electrocardiogram and/or Echocardiogram.
Prostaglandin E1 – given to the neonate to keep the ductus arteriosus patent. This is to provide pulmonary blood flow regardless of the stenotic pulmonary valve.
Balloon valvotomy – A balloon is passed through a vein to the heart to widen the narrowed part. Open heart Surgery is corrective surgery.