Aortic Regurgitation

Question 1

Define Aortic Regurgitation?

Answer 1

Retrograde blood flow, across the aortic valve from the aorta into the left ventricle during diastole due to a weakened aortic valve.

Also known as aortic insufficiency

Question 2

Explain the aetiology/risk factors of aortic regurgitation (2 mechanisms)

Answer 2

Aortic root/Ascending aorta dilation (MOST COMMON)

• Marfan’s/Ehlers-Danlos syndrome (causes dilation of aortic root)
• Aortic dissection (blood collection between aortic walls) - may cause acute presentation
• SYPHILLITIC aortitis

Aortic cusp/leaflet abnormalities

• Infective Endocarditis
• Rheumatic Fever
• Congenital BICUSPID aortic valve

Question 3

Summarise the epidemiology of aortic regurgitation

Answer 3

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

Question 4

Recognise the presenting symptoms of aortic regurgitation

Answer 4

• INITIALLY ASYMPTOMATIC as eccentric ventricular hypertrophy (increase LV volume) takes place to compensate and maintain a normal CO
  
  • But as chronic aortic regurgitation develops slowly over time, the LV dilates and congestive heart failure develops and that explains some of the symptoms:

1. Exertional Dyspnoea
2. Orthopnoea/Paroxysmal Nocturnal Dyspnoea
3. Fatigue & weakness
4. Angina (low diastolic pressures in aorta reduce coronary artery filling)

Question 5

Recognize the signs present on physical examination? (7)

Answer 5

1. Early-diastolic decrescendo murmur best heard at the 3rd left ICS parasternally (Erb’s point)
2. Austin-Flint murmur may be heard in mid/late diastole as the regurgitant blood may strike LV walls (diff from MS by OS)
3. S3 may be heard early diastole as the filing compliant dilated LV causes the LV wall to vibrate
4. Collapsing (Corrigan’s/Waterhammer pulse) shows a rapid/forceful/bounding upstroke AND rapid descent –>
   
   • This is due to the high systolic and low diastolic BP (a wide PP)
   • assess by lifting the arm over pt’s head
5. Bi-Basal crepitations
6. laterally and superiorly DISPLACED apex beat
7. Signs associated with forceful pulses
   
   • de Mussett’s sign: head bobbing with each systolic beat
   • Muller’s sign: pulsations of the uvula

Question 6

Describe the murmur heard by answering these questions?

1. Where is this heard loudest?
2. What extra heart sound can be heard?

Answer 6

• Heard best left parasternal border at 3rd ICS (Erb’s point) after expiration
• S3 may be heard early diastole as the filing compliant dilated LV causes the LV wall to vibrate

Question 7

Identify appropriate investigations for aortic regurgitation and interpret the results

Answer 7

• TT/TO echocardiography: diagnostic of AR, Can detect aetiology. Doppler flow to visualise the regurgitant jet
• ECG: May show LVH & LAD
  
  • Left axis deviation
  • Tall R in V5/6 (right side) & Deep S in V1/2 (left side)
• CXR
  
  • Cardiomegaly
  • Widened mediastinum (aortic dissection)
  • Signs of pulmonary oedema (if accompanied by left heart failure)