Aortic Stenosis

London Paediatric Cardiologist - Aortic Valve

Overview

The aortic valve is a one-way valve at the beginning of the major vessel taking blood to the body (Aorta). Aortic stenosis (AS) describes a condition where the aortic valve is smaller or tighter than it should be. As a consequence, the valve moves less freely and the heart has to contract harder to push blood across the valve. This can make the heart muscle thicken up as a consequence of this extra work. This may cause strain on the heart and makes it less efficient. The tightness commonly occurs at the valve site itself (valvar aortic stenosis) but can also be above the valve, in the vessel itself (supravalvar) or below the valve (sub-valvar stenosis). Frequently, the valve structure is abnormal and the valve leaflets (or doors) are thickened themselves or arranged in an unusual configuration with two leaflets rather than the usual three.

Presentation

Aortic stenosis may come to medical attention at any age. If the condition is mild, it may be picked up after the detection of heart murmur (an additional heart sound) at the postnatal or 6-week baby check. If the valve tightness is severe, babies may present with symptoms such as breathlessness or poor feeding, which reflect heart failure (at term used to describe a state where the heart function is insufficient to adequately meet the bodies needs). In older children and adolescents, symptoms tend to be rare. The presentation, may be once again, from the incidental finding of a murmur or from chest pain, fainting or dizziness on exercise.

Investigations

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The diagnosis is made by echocardiography, which is able to visualise the valve morphology (anatomic structure), quantify valve function and overall performance of the heart and circulation. An electrocardiogram (ECG) may be performed to assess for thickening of ventricular hypertrophy (thickening of the heart)

What is the Treatment?

Many factors determine the severity of the problem and the medical approach needed for care. Mild and moderate degrees of aortic stenosis often only require paediatric cardiology review in an outpatient capacity. If aortic stenosis is severe or causing symptoms, then treatment is likely to be needed. This will usually consist of either

a) Cardiac catheterisation and Intervention (a day-case, key-hole type procedure) to stretch the valve making it open more freely

b) Child Heart Surgery to improve flow across the valve.

Follow-up

The long-term outlook for aortic stenosis is usually good with many children requiring only one catheter or surgical procedure in childhood. The severity of the lesion and results of surgery heavily influence the need for further procedures. More severe forms of aortic stenosis, where the structure of the valve is very abnormal may lead to progressive valve dysfunction as the baby or child grows. Close medical follow up is important to assess for this and plan future surgery at the most appropriate (lowest risk) time.