What is Aortic Stenosis (AS)?

The aortic valve opens to allow blood to flow from the left ventricle to the aorta and the rest of the body. Aortic stenosis is a narrowing or obstruction below, above or at level of the aortic valve. It is most commonly due to a narrowing at the aortic valve and is classified according to the degree of obstruction as mild, moderate or severe.

Effects and Symptoms

Children with mild aortic stenosis can lead healthy, normal lives. They will have regular follow-up appointments to monitor for any changes and  if the narrowing remains mild, no specific actions are needed. Most children do not feel any symptoms with mild to moderate aortic stenosis.

In severe aortic stenosis in a newborn, the left ventricle, which pumps blood to the body, cannot pump enough blood to supply the body and the newborn will look unwell. They may look pale due to poor blood circulation and have increased work of breathing because fluid starts to build-up in the lungs. Immediate medical attention and treatment will be necessary.

Diagnosis

Aortic stenosis can present itself in different ways depending on the severity of obstruction. Children with mild to moderate aortic valve narrowing will have a murmur that can be heard during  a physical examination in an otherwise healthy, normal child. 

In newborns, when aortic stenosis is severe, there is a noticeable harsh murmur that can be heard on the chest. Within days or weeks after birth, as the ductus arteriosus closes, newborns may experience poor circulation throughout the body and fluid retention in the lungs. The ductus arteriosus is a blood vessel that connects the pulmonary artery and the aorta. It is normally present during fetal life and typically closes a few days after birth.

When a doctor suspects aortic stenosis, they may recommend an echocardiogram or ultrasound of the heart to confirm the diagnosis. This special test allows the doctor to see detailed images of the heart and its structures, helping to determine if there is indeed aortic stenosis present

In its most severe form, AS can be detected in the fetus and can be associated with an under-developed left ventricle. These findings can be seen during a fetal echocardiogram.

Management and Treatment

Children with mild to moderate aortic stenosis have regular visits with their cardiologist to monitor the degree of narrowing and development of symptoms. Those with mild to moderate stenosis and no symptoms typically do not need treatment.

Treatment for significant aortic stenosis aims to relieve the narrowing and improve circulation. This can be done in 2 ways: (1) cardiac catheterization or (2) open heart surgery. Newborns with critical aortic stenosis are given Prostaglandin E (PGE) which is a medication to keep the ductus arteriosus open to maintain circulation before cardiac catheterization or surgery.

Surgery

Balloon dilation valvuloplasty done during a Cardiac catheterization is often the first step to attempt to open the narrow valve by dilating the valve using a balloon. It does not require open-heart surgery.

Surgery is necessary in certain cases of aortic stenosis. These cases include when the narrowing is located above or below the aortic valve, when previous attempts to widen the narrowing using balloon dilation have been unsuccessful, or when the aortic valve is leaking or not functioning properly. In such situations, surgical intervention is indicated to address and correct the condition.

There are several different types of open heart surgery for aortic stenosis that either repair or replace the aortic valve. The choice will depend on many factors including previous procedures, the function of the heart and age of the child.

Adult and Adolescent Management

Stenosis can progress over time, requiring long-term cardiology follow up and potential surgical intervention as an adult. Patients whose valves were replaced with mechanical valves will need lifelong medication to prevent blood from clotting as quickly as normal (anticoagulation medication).