Aortic regurgitation
Description
- Diastolic reflux aorta -> LV = combined volume and pressure overload
| Acute | Chronic | |
|---|---|---|
| LV | Normal size, non-compliant | Dilated, compliant |
| Pulse pressure | Normal or narrow | Wide |
| Murmur | Short, soft | Long, holodiastolic |
| Presents as | Pulmonary oedema, shock | Asymptomatic for decades |
| Treatment | Emergency surgery | Timed by LV thresholds |
- Acute severe AR: all the classic peripheral signs are absent - severity is routinely underestimated
Epidemiology
- Less common than AS; prevalence rises with age
- M>F for chronic AR
- Bicuspid aortic valve in ~1-2% of population, M>F ~3:1
- Bicuspid + degenerative dominate in Australia; rheumatic dominates globally
- Rheumatic AR still prominent in Aboriginal and Torres Strait Islander populations
Aetiopathogenesis
By site
- Leaflet - bicuspid valve, rheumatic, endocarditis, degenerative, anorectic drugs
- Root / ascending aorta - HTN, cystic medial degeneration, Marfan, Ehlers-Danlos, dissection
- Aortitis - GCA, Takayasu, syphilis, ankylosing spondylitis
- Adjacent structures - sinus of Valsalva aneurysm, subaortic VSD
By tempo
- Acute - endocarditis, type A dissection, trauma
- Chronic - everything else
Mechanism
- Regurgitant volume -> inc LV preload
- -> eccentric hypertrophy + dilatation
- -> forward SV and EF preserved for years
- -> inc wall stress -> myocyte loss, fibrosis
- -> dec EF, often after damage is irreversible
- Wide pulse pressure = inc stroke volume + dec diastolic pressure
- Angina without CAD
- dec diastolic coronary perfusion pressure + inc LV mass
- Bradycardia lengthens diastole -> more regurgitation, worse angina
Diagnosis
Presentation
- Asymptomatic for decades, then exertional dyspnoea
- Angina without coronary disease - exertional or nocturnal
Exam
- Collapsing (Corrigan / water-hammer) pulse, wide pulse pressure
- Displaced, hyperdynamic apex
- Early diastolic murmur at LLSE - sitting forward, expiration
- Duration not intensity tracks severity; holodiastolic = severe
- Austin Flint murmur; ejection click if bicuspid
- Eponyms: de Musset, Quincke, Duroziez, Traube, Corrigan's sign
- Acute severe AR - short soft murmur, normal pulse pressure, tachycardia
Investigations
- TTE = primary test - severity, LV dimensions, EF, root diameter
- Severe if:
- Jet width >65% of LVOT, OR
- Regurgitant fraction >50%, OR regurgitant volume >60 mL/beat, OR
- EROA >0.3 cm2, OR
- Holodiastolic flow reversal in the descending aorta
- CT/MR angiography for root and ascending aorta
- CMR for regurgitant fraction and LV volumes when echo equivocal
- ECG: LVH, left axis deviation. CXR: cardiomegaly, aortic dilatation
Management
Acute severe AR
- Surgical emergency - urgent AVR or root repair
- Temporise: vasodilator (nitroprusside) +/- inotrope, treat the cause
- *IABP absolutely contraindicated* - augments regurgitation
- Avoid beta blockers even in dissection - removes compensatory tachycardia
Chronic AR - surveillance
- Asymptomatic with normal LV: echo 6-12 monthly (severe), 1-2 yearly (moderate)
- Exercise testing to unmask symptoms in the "asymptomatic"
Chronic AR - surgery
- Operate if any of:
- Symptomatic severe AR - regardless of EF
- Asymptomatic + EF <=55%
- Asymptomatic + LVESD >50 mm (or >25 mm/m2 indexed)
- LVEDD >65 mm with low surgical risk
- Undergoing other cardiac surgery
- The old 55 mm LVESD threshold is superseded - now 50 mm
- Root disease - operate at:
- >45 mm Marfan
- >50 mm bicuspid valve
- >55 mm all others
- AVR (mechanical vs bioprosthetic by age) or valve-sparing root replacement
- TAVI is not standard for pure native AR - no calcium to anchor the prosthesis
Medical therapy
Only for symptomatic patients awaiting surgery or unfit for it
- Vasodilators - ACEi/ARB or dihydropyridine CCB; diuretics for congestion
- Treat hypertension - directly reduces regurgitant volume
- *Avoid beta blockers* - bradycardia lengthens diastole -> inc regurgitation
- Exception: Marfan/aortopathy, where they slow root dilatation
Associations
- Bicuspid aortic valve - and its companion, coarctation
- Marfan, Loeys-Dietz, Ehlers-Danlos
- Ankylosing spondylitis and other HLA-B27 spondyloarthropathies
- Aortitis - giant cell, Takayasu, syphilis
- Rheumatic heart disease
- Infective endocarditis
- Anorectic drugs, ergotamine
Natural history & complications
- Asymptomatic with normal LV: <6%/yr progress to symptoms or LV dysfunction
- Asymptomatic with LV dysfunction: >25%/yr become symptomatic
- Symptomatic untreated: mortality ~10-20%/yr
- LV dysfunction reverses if operated early
- Prolonged dysfunction may never recover - this is why the thresholds exist
Monitor
- Symptoms - the trigger for surgery regardless of numbers
- EF, LVESD, LVEDD
- Root and ascending aorta diameter
- Endocarditis awareness
Complications
- Progressive LV dysfunction and heart failure
- Infective endocarditis
- Aortic dissection if aortopathy
- Sudden death - uncommon but recognised
🔒
6 more sections, plus exam facts
Premium unlocks every note across every specialty, and the full exam fact library behind it.
Get premium access