Aortic stenosis: symptoms, mechanisms and examination findings
THE CONTEXT
Aortic stenosis may be detected by its murmur before symptoms develop. Its three cardinal symptoms are angina, breathlessness and syncope.
Presentation and symptom mechanisms
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An ejection systolic murmur is commonly detected during routine examination of asymptomatic patients. Mild or moderate stenosis is usually asymptomatic.
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Angina can result from increased demands of the hypertrophied left ventricle working against high-pressure outflow obstruction, or from coexisting coronary artery disease, which affects over 50% of patients.
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Exertional breathlessness suggests cardiac decompensation from excessive left ventricular pressure overload.
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Syncope usually occurs during exertion when cardiac output fails to rise sufficiently, causing blood pressure to fall. Arrhythmias can also cause syncope and are usually poorly tolerated in haemodynamically significant aortic stenosis.
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Other listed presentations include sudden death and episodes of acute pulmonary oedema.
Examination and exercise assessment
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Signs include an ejection systolic murmur, a slow-rising carotid pulse, a heaving apex beat reflecting left ventricular pressure overload, narrow pulse pressure and pulmonary venous congestion.
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In patients with severe aortic stenosis who report no symptoms, a careful exercise test may reveal symptoms, hypotension or ischaemia on modest exertion.