Aortic regurgitation- valvular Flashcards
What is aortic regurgitation?
The retrograde flow (reflux) of blood from the aorta into the left ventricle during diastole
(regurgitation/insufficiency)
What are the causes of aortic regurgitation?
Aortic valve leaflet abnormalities/damage
- BIcuspid aortic valve
- infective endocarditis
- rheumatic fever
- trauma
Aortic root/ascending aorta dilation
- systemic hypertension
- aortic dissection –> ACUTE AR
- aortitis (secondary to syphilis)
- arthritides
- Marfan’s, Ehler-Danlos syndromes
- osteogenesis imperfecta
What is the pathophysiology of aortic regurgitation?
Summarise the epidemiology of aortic regurgitation.
- less common than mitral regurgitation & aortic stenosis
- males > females
- age (chronic begins in late 50s; most common in 80yrs+)
What are the risk factors of aortic regurgitation?
- bicuspid aortic valve
- rheumatic fever
- endocarditis
- Marfan’s syndrome and related connective tissue disease
- aortitis
weak
- systemic HTN
- older age
What are the types of aortic regurgitation & their most common causes?
-
acute = rapid decompensation as heart is unable to offset sudden increase in end diastolic volume (preload)
- causes: aortic dissection, infective endocarditis, trauma
-
chronic = over months/years,
- causes: Aortic enlargement from unclear aetiology; bicuspid congenital malformation
What is the typical time onset of AR?
- acutely
- over decades
- How should acute AR be treated?
- What are the complications of acute AR?
- medical emergency, high mortality
- acute rise in left atrial pressure, pulmonary oedema, and cardiogenic shock
What are the presenting symptoms of aortic regurgitation?
Chronic AR
- Initially ASYMPTOMATIC
- Later on, the patient may develop symptoms of heart failure (e.g. exertional dyspnoea, orthopnoea, fatigue)
Severe Acute AR
- Sudden cardiovascular collapse (left ventricle cannot adapt to the rapid increase in end-diastolic volume)
- Symptoms related to aetiology (e.g. chest or back pain caused by aortic dissection)
What are the signs of aortic regurgitation O/E?
- Collapsing (water-hammer) pulse
- Wide pulse pressure
- Thrusting and heaving displaced apex beat
- Early diastolic murmur over aortic valve region
- NOTE: an ejection systolic murmur may also be heard because of increased flow across the valve (due to increased stroke volume)
- Austin Flint mid-diastolic murmur
Where is an early diastolic murmur best heard?
- Heard better at the left sternal edge
- when the patient is sitting forward
- with the breath held at top of expiration
Where is an Austin Flint mid-diastolic murmur best heard?
- Heard over the apex
- Caused by turbulent reflux hitting the anterior cusp of the mitral valve –> a physiological mitral stenosis
What are some rare signs associated with aortic regurgitation?
- Quincke’s Sign - visible pulsation on nail bed
- de Musset’s Sign - head nodding in time with the pulse
- Becker’s Sign - visible pulsation of the pupils and retinal arteries
- Muller’s Sign - visible pulsation of the uvula
- Corrigan’s Sign - visible pulsation in the neck
- Traube’s Sign - pistol shot (loud systolic and diastolic sounds) heard on auscultation of the femoral arteries
- Duroziez’s Sign - systolic and diastolic bruit heard on partial compression of the femoral artery with the stethoscope
- Rosenbach’s Sign - systolic pulsations of the liver
- Gerhard’s Sign - systolic pulsations of the spleen
- Hill’s Sign - popliteal cuff systolic pressure exceeding brachial pressure by > 60 mm Hg
What are the primary investigations for ?aortic regurgitation
-
ECG
- provides only supportive evidence
-
CXR
- Chronic: left/inferior cardiomegaly
-
echocardiogram
- shows severity + aetiology of AR
- M-mode and 2-dimensional imaging
- indirectly assesses AR
- valvular anatomy
- assesses aortic root dilation
- monitors LV response to volume overload
-
Doppler
- colour flow - detection + quantification of regurgitant flow
- pulsed wave - detection + quantification of holodiastolic flow reversal
-
continuous wave - shorter pressure half-time or steeper slope of velocity deceleration in severe AR
- due to LV diastolic pressure rapidly increases –> aortic diastolic pressure rapidly falls
What might an ECG show in
a) chronic AR
b) acute AR
chronic: ~
- non-specific ST-T wave changes
- left axis deviation or
- conduction abnormalities
acute: ~
- non-specific ST-T wave changes
- sinus tachycardia or arrhythmias
- evidence of myocardial ischaemia
