Aortic stenosis
AS may be found in MRCPCH either without or following an operation. Depending on severity it may be asymptomatic or lead to sudden death.
Anatomy
Valvular (most common form), subvalvular and supravalvular aortic stenosis.
The most common cause for valvular artic stenosis is bicuspid aortic valve. Bicuspid aortic valve is commonly associated with coartation of aorta.
Conditions associated with aortic stenosis include Turner’s syndrome, William’s syndrome (mainly supravalvular) , coarctation of aorta, hypoplastic left valve / mitral valve abnormalities, phenytoin or hypertrophic obstructive cardiomyopathy.
Physiology
Outflow obstruction from the left ventricle leads to strain and hypertrophy of the LV. Clinical features are caused by either the reduced/limited cardiac output or the high left sided filling pressures causing pulmonary oedema.
These include dizziness, palpitation on exertion, easy fatiguability, exertional chest pain, syncope, dyspnoea, arrhythmia or sudden death.
Presentation depends upon the pressure gradient across the valve and the presence of regurgitation.
Management
Regular review with echocardiography.
For valvular aortic stenosis, balloon valvuloplasty when gradient reaches 64mmHg across the valve. Surgical valvotomy if balloon valvuloplasty unsuccessful or if patients develop aortic regurgitation following aortic dilatation.
Surgical valvotomy first choice for supravalvular and subvalvular aortic stenosis.
A neonate with critical aortic stenosis may have a duct dependent defect, where blood supply to the systemic circulation is dependent on right to left flow across the ductus. Prostaglandin and early surgical intervention is required.
Clinical
Asymptomatic or….
Ejection systolic murmur at right upper sternal edge, radiating to the neck, sometimes with a suprasternal notch/carotid thrill.
Ejection click at apex/ LLSE (if valvular)
Diastolic murmur at apex due to aortic regurgitation (if valvular)
Quiet A2 (second heart sound of aortic component)
Investigations
ECG – Left ventricular hypertrophy
CXR – Normal. Or enlargement of left ventricle. Poststenotic dilation of ascending aorta / aortic knob
Exam vignette
I examined Peter, a 7-year-old boy who looks well-grown for his age and I would like to plot his height and weight on a growth chart.
He is pink and not in respiratory distress. There are no dysmorphic features or finger clubbing. There are no scars on his chest. There is a palpable thrill at his suprasternal notch. He has a grade 3/6 ejection systolic murmur at right upper sternal edge radiating to carotid area.
He has left ventricular outflow obstruction such as aortic stenosis.
