Severe Aortic Stenosis

Fixed obstruction to left ventricular outflow. A chronic disease with two acute lessons for an on-call doctor. First, exertional syncope marks a sharply worse prognosis and is not a faint to send home. Second, a fixed outflow tract cannot compensate…

Fixed outflow tract — syncope is the red flag, vasodilators are dangerous

The pathway

1 · Recognise it on examination

Ejection systolic murmur radiating to the carotids
Slow-rising, low-volume pulse
Narrow pulse pressure
Severe disease: a quiet or absent second heart sound, a late-peaking murmur
Murmur loudness cannot reliably grade severity — severe AS can have a relatively quiet murmur

2 · The triad that changes the prognosis

Syncope during exertion — a major cardiac red flag, and the worst of the three. (Syncope shortly AFTER stopping exercise can still be vasovagal)
Angina
Breathlessness / heart failure
Once symptoms appear, untreated survival shortens markedly, and syncope is the symptom that should get the fastest cardiology response

3 · ⚠ Be careful with anything that drops preload or afterload

GTN for chest pain can cause profound hypotension — the classic ward harm
Same for other vasodilators, and for aggressive diuresis
Spinal and epidural anaesthesia carry real risk and are an anaesthetic risk-management decision, not an automatic contraindication — the anaesthetist must know about the valve
If hypotension occurs, fluid and a vasopressor under senior guidance — not more vasodilator

4 · Investigate

ECG — left ventricular hypertrophy, sometimes conduction disease
Echocardiogram is the test: gradient, valve area, ventricular function
CXR, bloods, BNP as clinically indicated
An undiagnosed murmur before non-cardiac surgery is flagged to anaesthetics
Obtain an urgent echo where significant valve disease is suspected AND the result would change management — not reflexively for every murmur

5 · The other associations worth knowing

*Worth knowing rather than acting on:* Heyde syndrome — AS with gastrointestinal bleeding from angiodysplasia, related to acquired von Willebrand disease
Conduction disease from calcification spreading into the septum
Infective endocarditis risk on an abnormal valve
Atrial fibrillation is poorly tolerated — the atrial contribution to filling matters here more than usual

6 · Refer

Symptomatic severe AS is a cardiology referral, urgently — the treatment is valve replacement, surgical or transcatheter
Syncope, heart failure or angina in known severe AS should not go home from the emergency department without a cardiology conversation
Asymptomatic severe AS needs surveillance rather than admission

Drugs

Drug	Dose	Route	Notes
GTN	Caution — may cause profound hypotension	SL / IV	The classic harm in this condition. A fixed outflow tract cannot compensate for the fall in preload.
Diuretics	Cautiously, per senior advice	IV / PO	Needed in fluid overload, but over-diuresis drops preload in a ventricle that depends on it.
Vasopressor	Per critical care	IV	For hypotension in severe AS, under senior guidance. Restoring afterload is the aim.

When to escalate

Exertional syncope with an ejection systolic murmur — cardiology before discharge,Hypotension after GTN in a patient with a murmur — stop it, fluid, senior help,Undiagnosed murmur listed for surgery — tell anaesthetics; urgent echo if significant valve disease is suspected and it would change management. In hip fracture, do not let this delay surgery — NICE prioritises operating on the day of or the day after admission,New heart failure in known severe AS — cardiology urgently; this is a valve problem

Reference: ESC/EACTS guidelines on the management of valvular heart disease; NICE guidance on heart valve disease. Local cardiology and anaesthetic pathways take precedence.

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