Differentials
Aortic stenosis (AS)
SIGNS / SYMPTOMS
Presenting features vary depending on the severity of stenosis. With mild AS, the patient may be asymptomatic with a harsh systolic ejection quality murmur at the upper right sternal border with radiation to the carotids on physical examination. In moderate or severe AS, the patient may have significant shortness of breath, especially on exertion.
INVESTIGATIONS
Differentiated from coarctation of the aorta by echocardiogram.
Two-dimensional echocardiogram of the aortic valve shows an abnormally narrowed or dysplastic aortic valve.
Colour Doppler and pulse Doppler across the aortic valve show turbulent blood flow across the valve and are used to measure the gradient.
Patients with aortic coarctation with associated bicuspid aortic valve may also have AS.
Interrupted aortic arch
SIGNS / SYMPTOMS
Presents as shock in neonates. Unable to clinically differentiate between interruption of the aortic arch and critical coarctation of the aorta.
INVESTIGATIONS
Echocardiogram will differentiate the severe narrowing seen in critical coarctation from a frank interruption.
Left ventricular outflow tract obstruction
SIGNS / SYMPTOMS
Depending on the level and severity of the obstruction, patients may be asymptomatic or may present with shortness of breath, especially on exertion.
INVESTIGATIONS
An echocardiogram will differentiate the level of the obstructed or narrowed area in the aorta. Using colour and pulse Doppler, any narrowing in the left ventricular outflow tract can be localised to the valvar, sub-valvar, or supra-valvar area, or across the aortic arch.
Essential hypertension
SIGNS / SYMPTOMS
Similar clinical presentation.
Lower extremity pulses are usually normal unless peripheral vascular disease present.
INVESTIGATIONS
Four-extremity blood pressure shows no gradient.
Echocardiogram shows normal flow across the aortic arch and normal Doppler of the abdominal aorta.
Renal artery stenosis
SIGNS / SYMPTOMS
Similar clinical presentation.
INVESTIGATIONS
Renal artery Doppler shows renal artery stenosis.
Normal echocardiogram.
Phaeochromocytoma
SIGNS / SYMPTOMS
Hypertension with associated symptoms such as palpitations and flushing.
INVESTIGATIONS
A 24-hour urine collection is positive for elevated urine creatinine, metanephrines, and catecholamines.
Use of this content is subject to our disclaimer