Aortic Stenosis

A quick 'vivacast' containing all the sorts of questions that you may get asked if you see a patient in OSCEs/PACES with aortic stenosis.

 

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Video Duration: 4 minutes

  • Aortic Stenosis
    Created by Matthew Ball
    General
    Epidemiology

    Aortic stenosis (AS) is a number of different pathologies resulting in the narrowing of the aortic valve.

    Prevalence increases with age.

    Worldwide most commonly due to rheumatic heart disease but in Europe and the US most commonly due to degenerative scarring and calcification.

    Pathology

    A degenerative pathologies lead to scarring, stiffening and narrowing of the aortic valve, either as a result of aging or a predisposing condition which leads to increased stress on the valve leaflets.

    • Degenerative/Calcification
      • Same mechanisms --> Damage --> calcification
    • Bicuspid (congenital)
      • Increased turbulence → damage to leaflets → fibrosis/calcification and stenosis
    Top three causes
    • Degenerative Changes
    • Congenital Biscuspid Aortic Valve
    • Rheumatic valve disease (rarer)
    Clinical Features
    Symptoms

    Varies dependent on severity:

    • Mild to moderate - often none
    • Severe
      • Syncope or dizziness (presyncope)
        • Especially on exertion
        • Due to decreased brain perfusion
      • Angina
        • Again on exertion
        • Coronary arteries may be normal
        • ↓BP → ↓coronary artery filling pressure
      • Dyspnoea
        • on exertion or decreased exercise tolerance
        • Probably not due to Pulmonary oedema
        • May be just breathing hard to increase O2 delivery to myocardium
      • Symptoms of LVF
        • Late - indicate very severe AS
    Signs

    4 Key signs

    • Slow rising pulse
      • May not be present in the elderly as loss of arteriolar elasticity masks effect
    • Low B.P
      • Narrow pulse pressure
      • In elderly this may be counteracted by the widened pulse pressure due to in-elastic arteries
    • Systolic Murmur
      • Cannot distinguish severity from sound
      • Once very severe heart sound becomes softer (Soft S2)
    • Radiation to Carotids

    Also:

    • Hyperdynamic apex beat
      • Left ventricular hypertrophy
    • Soft S2
      • Leaflets no longer slam shut
    • Pulmonary oedema if severe
    • Raised JVP if severe enough for Heart failure
    Investigations
    Cultures

    Unless presenting as a new onset murmur with fever of unknown origin the always think Endocarditis (and appropriate tests)

    Bloods
    • FBC
      • Anaemia may exacerbate symptoms
    • U&E
      • In case of need to use diuretics
    • Fasting Lipids
      • To measure cardiac risk factors
    Imaging
    • Chest X-ray
      • May reveal signs of heart failure in advanced disease
    Scopic/Biopsy

    None

    Functional
    • Echocardiography
      • Can use doppler to judge ejection fraction
    • Cardiac Catheterisation to measure pressure gradient across valve
      • indicated if suspected but echocardiography is not diagnositic
    • ECG (+/- exercise testing)
      • to determine if the severity is sufficient to lead to Myocardial Ischaemia
    Treatment
    Conservative
    • Measure and treat cardiovascular risk factors
    • Monitoring of AS severity if asymptomatic

    Severity

    Echocardiography monitoring

    Mild AS

    every three to five years.

    Moderate AS

    every one to two years

    Severe AS

    every 6 to 12 months

    Medical

    Among patients with asymptomatic AS, there are no medical therapies that have been proven to delay progression of disease.

    Surgical

    Aortic valve replacement

    (Indicated once there is onset of symptoms)

    Percutaneous

    Surgical

    Valve balloon plasty + insertion of valve graft.

    Open surgery with valve replacement.