AKT · Cardiovascular/Valves & endocardium

Aortic stenosis

Calcific/degenerative (or bicuspid/rheumatic) narrowing of the aortic valve → LV outflow obstruction

Overview

Narrowing of the aortic valve causing fixed LV outflow obstruction. The commonest cause is senile calcific degeneration; a bicuspid valve causes it earlier. The classic triad of exertional Syncope, Angina and Dyspnoea (SAD) marks symptomatic severe disease — a turning point, because symptomatic severe AS has a poor prognosis and needs valve replacement.

Recognise

Ejection systolic murmur at the right upper sternal edge radiating to the carotids; soft/absent S2; slow-rising (parvus et tardus) pulse; narrow pulse pressure
Symptoms (late, ominous): exertional syncope, angina, dyspnoea/heart failure
Bicuspid valve → presents younger; rheumatic AS usually with mitral disease

Red flags

Onset of symptoms (syncope/angina/dyspnoea) in severe AS → urgent referral for valve replacement (poor prognosis untreated)
Avoid pre-load/afterload reducers (nitrates, ACE inhibitors) in severe AS — can cause profound hypotension/syncope

Differentials & how to tell them apart

Hypertrophic cardiomyopathymurmur INCREASES with Valsalva/standing; no carotid radiation; dynamic obstruction

Aortic sclerosismurmur without significant gradient or pulse/pressure changes; normal S2

Mitral regurgitationpansystolic at the apex radiating to the axilla

Investigations

Echo is diagnostic and grades severity (valve area, peak gradient, jet velocity); ECG (LVH); CXR; coronary angiography before surgery; exercise testing in asymptomatic severe AS under specialist guidance.

Management

Aortic valve replacement (SAVR or TAVI) once symptomatic/severe

1Confirm and grade with echo. Asymptomatic patients are monitored; manage risk factors and avoid vasodilators in severe disease.Gate: Development of symptoms (syncope, angina, dyspnoea) or severe AS with LV dysfunction → refer for aortic valve replacement — symptomatic severe AS has a poor prognosis untreated.
2Valve replacement: surgical (SAVR) for lower-risk/younger patients, TAVI for higher-risk/elderly; coronary assessment first.

Aortic valve replacement — surgical (SAVR) or transcatheter (TAVI) — definitive; TAVI for higher-surgical-risk/elderly patients; the only treatment that improves prognosis

Manage comorbidities/risk factors — there is no medical therapy that alters AS itself; treat hypertension cautiously

Avoid vasodilators in severe AS — nitrates/ACEi can precipitate syncope

Key points

Ejection systolic murmur radiating to the carotids + slow-rising pulse + narrow pulse pressure = aortic stenosis. Once it causes Syncope, Angina or Dyspnoea (SAD) it is symptomatic severe AS → valve replacement. Avoid nitrates/ACEi (precipitate hypotension).

Monitor & prognosis

Serial echo for asymptomatic patients; prompt review on new symptoms.

Symptomatic severe AS: ~50% 2-year mortality untreated; excellent after replacement.

Source: NICE NG208 (heart valve disease); ESC