Aortic valve disease

Overview

•Classic triad - SAD (order tracks disease progression):

•Syncope (exertional) - fixed obstruction prevents CO rising → cerebral hypoperfusion; ~2-3 years median survival without intervention

•Angina (exertional) - high O₂ demand in hypertrophied LV + reduced coronary perfusion; ~3-5 years

•Dyspnoea (exertional → rest) - LV failure as compensation is lost; ~1-2 years

💡
Exertional syncope in aortic stenosis: during exercise, peripheral vasodilation occurs but the fixed obstruction prevents cardiac output rising → cerebral perfusion falls → syncope.

Investigations

🏆 Gold standard

•Transthoracic echocardiogram (TTE) - confirms diagnosis, quantifies severity, assesses LV function

•Severe AS criteria (all three): peak gradient >40 mmHg, valve area <1.0 cm², aortic jet velocity >4 m/s

•ECG - may show LVH (tall R in V5-V6, deep S in V1-V2), left axis deviation

⚠️
Low-flow, low-gradient AS: in poor LV function, the peak gradient may be falsely low despite a critically narrow valve - valve area (<1.0 cm²) is the more reliable severity marker in this situation.

Follow-up

•Asymptomatic severe AS - echo every 6 months

•Asymptomatic mild-moderate AS - echo annually

•Post-SAVR mechanical valve - lifelong warfarin (INR 2.5-3.5 for aortic position); regular INR monitoring

•Post-SAVR bioprosthetic valve - no routine long-term anticoagulation; may need re-intervention after 10-15 years

Aortic Stenosis - Examination Findings

•Ejection systolic murmur - crescendo-decrescendo, loudest at 2nd intercostal space right sternal border, radiates to carotids

•Slow-rising (parvus et tardus) carotid pulse - reduced stroke volume

•Narrow pulse pressure - fixed obstruction reduces systolic ejection

•Heaving, non-displaced apex beat - concentric LVH

•Soft or absent S2 - calcified immobile leaflets; correlates with severity

Aortic Regurgitation - Presentation & Examination

•Chronic AR - insidious exertional dyspnoea and fatigue; Acute AR (endocarditis/dissection) - sudden pulmonary oedema or cardiovascular collapse

•Early diastolic murmur - soft, high-pitched, left sternal border, held expiration leaning forward

•Collapsing (water-hammer) pulse - wide pulse pressure; felt by elevating the arm

•Wide pulse pressure - high stroke volume raises systolic; diastolic runoff lowers diastolic BP

•Displaced, hyperdynamic apex beat - eccentric LV dilatation

•Austin-Flint murmur - mid-diastolic rumble at apex; regurgitant jet impinges anterior mitral leaflet; mimics mitral stenosis

AS vs AR - Key Differences

Aortic stenosis vs aortic regurgitation
FeatureAortic stenosisAortic regurgitation
LV responsePressure overload → concentric LVHVolume overload → eccentric dilatation
MurmurEjection systolic (crescendo-decrescendo), 2nd ICS RSB → carotidsEarly diastolic, left sternal border
PulseSlow-rising, narrow pulse pressureCollapsing, wide pulse pressure
Apex beatHeaving, non-displacedDisplaced, hyperdynamic

Feature	Aortic stenosis	Aortic regurgitation
LV response	Pressure overload → concentric LVH	Volume overload → eccentric dilatation
Murmur	Ejection systolic (crescendo-decrescendo), 2nd ICS RSB → carotids	Early diastolic, left sternal border
Pulse	Slow-rising, narrow pulse pressure	Collapsing, wide pulse pressure
Apex beat	Heaving, non-displaced	Displaced, hyperdynamic

Management - Aortic Stenosis

•Symptomatic AS → early surgical intervention regardless of echocardiographic severity; no medical therapy arrests progression

Step 1 · Assess surgical risk and age
1All symptomatic severe AS patients require valve intervention
↓
Low surgical risk, age <65
SAVR with mechanical valve - durability ~20-30 years; requires lifelong warfarin (target INR 2.5-3.5 for aortic position)
Low surgical risk, age >65
SAVR with bioprosthetic valve - lasts 10-15 years; no long-term anticoagulation required; may need re-intervention
High surgical risk or frailty
TAVI - transfemoral approach; no sternotomy or cardiopulmonary bypass required
↓
Reserve · Bridge only
1Balloon aortic valvuloplasty - temporary measure only; reserved for critically ill patients, cardiogenic shock, or as bridge to SAVR/TAVI; high re-stenosis rate within 6 months; no mortality benefit

Management - Aortic Regurgitation

•Medical: beta-blockers or ACE inhibitors for hypertension control - reduces aortic root dilatation rate

•Surgical aortic valve replacement (SAVR) indications:

•Symptomatic AR of any severity

•Asymptomatic AR with LVEF <50%

•Asymptomatic AR with LV end-diastolic diameter >70 mm or LV end-systolic diameter >50 mm

•Infective endocarditis refractory to medical therapy

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Acute AR (e.g. from endocarditis or dissection) is a medical emergency - no time for compensatory LV dilatation; can rapidly cause pulmonary oedema and cardiogenic shock requiring emergency surgery.