Aortic regurgitation

Question 1

Define

Answer 1

• Reflux of blood from the aorta into the left ventricle during diastole. Also known as aortic insufficiency. It can remain asymptomatic for decades before patients present with irreversible myocardial damage.

Question 2

What are the risk factors?

Answer 2

• Aortic valve leaflet abnormalities or damage
o Bicuspid aortic valve
o Infective endocarditis
o Rheumatic fever (in developing countries, most common cause)
o Trauma

•	Aortic root/ascending aorta dilatation
o	Systemic hypertension
o	Aortic dissection 
o	Aortitis secondary to syphilis 
o	Arthritides (e.g. rheumatoid arthritis, seronegative arthritides)
o	Connective tissue disease (e.g. Marfan's, Ehlers-Danlos)
o	Pseudoxanthoma elasticum
o	Osteogenesis imperfecta

Question 3

What is the pathophysiology?

Answer 3

Pathophysiology:
o Reflux of blood into the left ventricle results in left ventricular dilatation
o This means increased end diastolic volume and increased stroke volume
o The combination of increased stroke volume and low end-diastolic AORTIC pressure may explain the high-volume collapsing pulse

Acute aortic regurgitation:
A medical emergency where the left heart rapidly decompensates due to its inability to handle a sudden increase in end-diastolic volume. Most commonly it results from aortic dissection or endocarditis and, in rare cases, trauma.

Chronic aortic regurgitation:
Chronic regurgitation has a prolonged course over a period of months to years. The left ventricle is able to compensate for volume overload initially but then decompensates with the appearance of clinical symptoms of congestive heart failure.

Question 4

Epidemiology

Answer 4

• Chronic AR often begins in the late 50s

* It is most frequently seen in patients > 80 yrs

Question 5

What are the presenting symptoms?

Answer 5

• Chronic AR
o Initially ASYMPTOMATIC
o Later on, the patient may develop symptoms of heart failure (e.g. exertional dyspnoea, orthopnoea, fatigue)
• Severe Acute AR
o 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)

Question 6

What are the signs?

Answer 6

• Symptoms of cardiogenic shock: pallor, mottled extremities, rapid and faint peripheral pulse, jugular venous distension, altered mental status, urine output <30ml/hr
• Collapsing (water-hammer) pulse
• Wide pulse pressure
• Thrusting and heaving displaced apex beat
• Early diastolic murmur
o Heard better at the left sternal edge in 4th ICS when the patient is sitting forward with the breath held at the top of expiration
• NOTE: an ejection systolic murmur may also be heard because of increased flow across the valve (due to increased stroke volume)

Question 7

What are the uncommon signs?

Answer 7

• Austin Flint mid-diastolic murmur (uncommon)
o Heard over the apex
o Caused by turbulent reflux hitting the anterior cusp of the mitral valve causing a physiological mitral stenosis

• Rare signs associated with aortic regurgitation:
o Quincke’s Sign - visible pulsation on nail bed
o de Musset’s Sign - head nodding in time with the pulse

o Becker’s Sign - visible pulsation of the pupils and retinal arteries
o Muller’s Sign - visible pulsation of the uvula
o Corrigan’s Sign - visible pulsation in the neck
o Traube’s Sign - pistol shot (loud systolic and diastolic sounds) heard on auscultation of the femoral arteries
o Duroziez’s Sign - systolic and diastolic bruit heard on partial compression of the femoral artery with the stethoscope
o Rosenbach’s Sign - systolic pulsations of the liver
o Gerhard’s Sign - systolic pulsations of the spleen
o Hill’s Sign - popliteal cuff systolic pressure exceeding brachial pressure by > 60 mm Hg

Question 8

What are the appropriate investigations?

Answer 8

• CXR
o Cardiomegaly
o Dilatation of ascending aorta
o Signs of pulmonary oedema (if accompanied by left heart failure)
• ECG
o May show left ventricular hypertrophy
• Deep S in V1/2
• Tall R in V5/6
• Inverted T waves in lead I, aVL, V5/6
• Left axis deviation
• Echocardiogram (preferred method)
o May show underlying cause (e.g. aortic root dilatation, bicuspid aortic valve)
o May show the effects of aortic regurgitation (e.g. left ventricular dilatation, fluttering of the anterior mitral valve leaflet)
o Doppler echocardiogram can show AR and indicate severity
o Repeat echos allow monitoring of progression (LV size and function)
• Cardiac catheterisation with angiography
o If there is any uncertainty about the functional state of the ventricle or the presence of coronary artery disease