Aortic Regurgitation
Last modified: 12 December 2021, 3:03:25 PM AEDT
Gems / Priorities1 / 12
- CAUSE + SEVERITY + HAEMODYNAMIC consequences
- main problems = LV overload
- priorities = optimise LV filling
- goals
- FULL, FAST, FORWARD
Definition / diagnostic criteria2 / 12
- Colour Doppler echocardiography
Classification3 / 12
-
Onset
- Acute AR = surgical emergency
- Chronic AR = likely silent
-
Structural parameters
| Mild | Moderate | Severe | |
|---|---|---|---|
| AV leaflets | N / abN | N / abN | abN/flail |
| LV size | Normal | N/dilated | Dilated |
- Semi-quantitative Doppler parameters
| Severity | Mild | Moderate | Severe |
|---|---|---|---|
| VC (mm) | < 3 | 3 - 6 | > 6 |
| JW/LVOT (%) | < 25 | 25 - 65 | > 65 |
- Quantitative parameters
| Severity | Mild | Moderate | Severe |
|---|---|---|---|
| RVol (ml/beat) | < 30 | 30 - 59 | 60+ |
| RVol (L/min) | 1 - 3 | 3 - 5 | 6+ |
| RF (%) | < 30 | 30 - 49 | 50+ |
| EROA (cm2) | < 0.1 | 0.1 - 0.29 | 0.30+ |
Terms4 / 12
- VC = vena contracta
- width of regurgitant jet
- severe = wide > 0.6 cm
- narrowest part of regurgitant jet downstream of the regurgitant jet
- reflective of the EROA
- JW = Jet Width
- LVOT = LV outflow tract
- PHT = pressure half-time
- time for peak PG to halve
- severe = short half time
- RVol = regurgitant volume
- L/min at 100 bpm
- RF = regurgitant fraction
- EROA = effective regurgitant orifice area (cm2)
Aetiology / Causes / Risk Factors5 / 12
-
Patient
- Abnormal leaflets
- congenital = bicuspid, unicuspid, quadricuspid
- acquired = endocarditis (perforation), RHD, calcification (degenerative; prolapse)
- Abnormal aorta
- congenital = bicuspid AV, CT disease (eg. Marfan's)
- acquired = HTN, SLE, Ankylosing spondylitis, dissection, syphilis, trauma
- Abnormal leaflets
-
Acute
- IE / Type A AD / blunt chest trauma
-
Chronic
- Calcific
- Bicuspid
- Rheumatic
- Collagen vascular disease
-
HTN commonest cause of mild AR
Pathophysiology6 / 12
-
VOLUME OVERLOAD
-
LA volume overload
- LA dilatation
- ⬆risk ischaemia, arrhythmias
-
acute LV volume overload
- retrograde flow during diastole
- ⬆⬆SV
- rapid decompensation
- no time for compensatory LV dilatation to accommodate ⬆volume
- equilibration of aortic and LV pressures
-
compensation
- ⬆HR, ⬆INO (Starlings)
- LV dilatation to accommodate ⬆EDV
-
eventual decompensation
- progressive LV dilatation
Symptoms / History7 / 12
- SOBOE
- Angina
- LVF
Signs / Examination8 / 12
-
Collapsing pulse = ⬇⬇DBP
-
Wide pulse pressure = ⬇⬇DBP
-
Corrigan's sign = neck pulsation
-
De Musset's sign = head bobbing
-
murmur
- early diastolic murmur in held expiration, sat forward, at LLSE
Investigations9 / 12
-
TTE
- acute severe
- LV not dilated
- small jet
- chronic severe
- LV dilated and globular
- jet visible in all views
- acute severe
-
CXR
- cardiomegaly
- signs of LVF
Management10 / 12
- vasoD = no evidence
- AVR
Anaesthetic considerations11 / 12
- Pre-op
- Intra-op
- Goals
- maintain forward flow
- ⬇regurgitant volume
- 1:preload
- full = adequate volume
- LV needs adequate PL for CO (to compensate for the regurgitant fraction)
- do not give GTN (⬇PL ⮕ ⬇⬇CO)
- 2:rate
- fast = aim HR 90 bpm
- treat bradyC
- ⬇time for regurgitation so ⬇LV distension
- 3:rhythm
- patients cope well with AF (strangely)
- 4:contractility
- contractility may be impaired + LV dilated
- consider inodilators / b-agonists
- dobutamine
- 5:afterload
- aim ⬇SVR
- avoid ⬇SVR (opposes forward flow, worsens AR)
- avoid excessive AL ***
- assists forward flow
- neuraxial block may be helpful (beware hypotension and bradycardia)
- IABP contra-indicated
- Goals
- Post-op
Links / References12 / 12
Final FRCA In A Box
https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-18/chronic-aortic-regurgitation-diagnosis-and-therapy-in-the-modern-era
https://www.asecho.org/wp-content/uploads/2018/05/0507-1500-Wiegers-Quantitation-of-Aortic-Regurgitation.pdf
https://derangedphysiology.com/main/required-reading/cardiothoracic-intensive-care/Chapter%202.1.3/aortic-regurgitation