Aortic regurgitation

Question 1

Define aortic regurgitation and summarise its aetiology and epidemiology.

Answer 1

Definition: Reflux of blood from aorta into left ventricle (LV) during diastole aka aortic insufficiency

Aetiology:
- Aortic valve leaflet abnormalities or damage:
   • Bicuspid aortic valve
   • Infective endocarditis
   • Rheumatic fever
   • Trauma 

- Aortic root/ ascending aorta dilation:
   • Systemic hypertension
   • Aortic dissection 
   • Aortitis
   • Arthitides (e.g. rheumatoid arthritis, seronegative arthritides)
  seronegative	
 

Pathophysiology:

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

Epidemiology:

• Chronic AR often begins in the late 50s
• It is most frequently seen in patients > 80 years

Question 2

Describe the history/presenting symptoms of aortic regurgitation

Answer 2

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

Question 3

What are the signs of aortic regurgitation upon physical examination?

Answer 3

• Collapsing (water-hammer) pulse
• Wide pulse pressure
• Thrusting and heaving displaced apex beat
• Early diastolic murmur over the aortic valve region
  • Heard better at the left sternal edge 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)
• Austin Flint mid-diastolic murmur
  • Heard over the apex
  • Caused by turbulent reflux hitting the anterior cusp of the mitral valve causing a physiological mitral stenosis.

Question 4

What investigations are used to identify aortic regurgitation?

Answer 4

• CXR:
  • Cardiomegaly
  • Dilatation of ascending aorta
  • Signs of pulmonary oedema (if accompanied by left heart failure)
• ECG:
  • 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:
  • May show underlying cause (e.g. aortic root dilatation, bicuspid aortic valve)
  • May show the effects of aortic regurgitation (e.g. left ventricular dilatation, fluttering of the anterior mitral valve leaflet)
  • Doppler echocardiogram can show AR and indicate severity.
  • Repeat echos allow monitoring of progression. (LV size and function)
• Cardiac catheterization with angiography
  • If there is any uncertainty about the functional state of the ventricle or the presence of coronary artery disease

Question 5

What are some of the rare signs associated with aortic regurgitation?

Answer 5

• Quincke’s sign: Visible pulsations on nail-bed.
• de Musset’s sign: Head nodding in time with pulse.
• Becker’s sign: Visible pulsations of the pupils and retinal arteries.
• M€uller’s sign: Visible pulsation of the uvula.
• Corrigan’s sign: Visible pulsations in neck.
• Traube’s sign: ‘Pistol shot’ (systolic and diastolic sounds) heard on auscultation of the
  femoral arteries.
• Duroziez’s sign: A systolic and diastolic bruit heard on partial compression of femoral artery
  with a 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 mmHg.