Aortic Regurgitation

Question 1

What is aortic regurgitation?

Answer 1

The diastolic leakage of blood from the aorta into the left ventricle. It occurs due to inadequate coaptation of valve leaflets resulting from either intrinsic valve disease or dilation of the aortic root.

Question 2

What risk factors are associated with aortic regurgitation?

Answer 2

• Bicuspid aortic valve
• Rheumatic fever
• Endocarditis
• Marfan’s syndrome and related connective tissue disease
• Aortitis

Question 3

What are the signs of aortic regurgitation?

Answer 3

• Diastolic murmur
  *

Question 4

What are the symptoms of aortic regurgitation?

Answer 4

• Dyspnoea
• Fatigue
• Weakness
• Orthopnoea
• Paroxysmal nocturnal dyspnoea

Question 5

What murmur is heard in aortic regurgitation?

Answer 5

Diastolic murmur

Question 6

What are the signs and symptoms of pulmonary oedema?

Note: aortic regurgitation can present acutely with pulmonary oedema

Answer 6

• Dyspnoea
• Pink frothy sputum
• Pale and sweaty
• Basal lung crepitations
• Wheeze (cardiac asthma)

Question 7

What are the signs and symptoms of cardiogenic shock?

Note: aortic regurgitation can present acutely with cardiogenic shock

Answer 7

• Pale and/or cyanotic, cool to touch with mottled extremities
• Evidence of hypoperfusion with altered mental status and decreased urine output
• Rapid and faint peripheral pulses
• Jugular venous distension
• Third and fourth heart sounds may be present
• Arrhythmias
• Dyspnoea

Question 8

What investigations should be ordered for aortic regurgitation?

Answer 8

• ECG
• CXR
• Echocardiogram
• M-mode and 2-dimensional imaging
• Colour flow Doppler
• Pulse flow Doppler
• Continuous wave doppler

Question 9

Why investigate using ECG? And what may this show?

Answer 9

• Provides only supportive evidence. Echocardiography is required to confirm the presence of AR.
• May show non-specific ST-T wave changes, left axis deviation or conduction abnormalities.

Question 10

Why investigate using CXR? And what may this show?

Answer 10

• Chronic AR may produce cardiomegaly in the leftwards and inferior direction due to compensatory eccentric hypertrophy from increased end-diastolic volume. The aortic knob is typically prominent in severe hypertensive patients and those with aortic root dilation.
• May show cardiomegaly.

Question 11

Why investigate using an echocardiogram? And what may this show?

Answer 11

• The preferred method for non-invasive detection and evaluation of the severity and aetiology of aortic regurgitation.
• Visualisation of the origin of regurgitant jet and its width; detection of cause of aortic valve pathology.

Question 12

Why investigate using M-mode and 2-dimensional imaging? And what may this show?

Answer 12

• Helps indirectly assess AR. Two-dimensional echocardiography is very important in evaluating the valvular anatomy, assessing aortic root dilation, and monitoring the left ventricular response to volume overload.
• Assessment of valvular anatomy, aortic root dilation, and left ventricular response to volume overload.

Question 13

Why investigate using colour flow Doppler? And what may this show?

Answer 13

• Used to judge the severity of the regurgitant flow by using the ratio of proximal jet width.
• Tetection and quantification of regurgitant flow.

Question 14

Why investigate using pulse wave Doppler? And what may this show?

Answer 14

• Pulsed wave Doppler can quantitate this effect by assessing the regurgitant stroke volume and effective regurgitant orifice area.
• Detection and quantification of holodiastolic flow reversal.

Question 15

Why investigate using continous wave Doppler? And what may this show?

Answer 15

• As aortic regurgitation gets worse, left ventricular diastolic pressure rapidly increases and aortic diastolic pressure rapidly falls, resulting in shorter pressure half-time or steeper slope of velocity deceleration. These measures can be used as part of the assessment of AR severity.
• May show shorter pressure half-time or steeper slope of velocity deceleration in severe AR.

Question 16

Briefly describe the treatment for acute aortic regurgitation

Answer 16

Acute AR is a surgical emergency. Patients require assessment and management of the airway, with intubation if necessary. Positive inotropic agents (e.g., dopamine and dobutamine) and a vasodilator (e.g., sodium nitroprusside) are recommended for haemodynamic support. The definitive management is with urgent surgery (aortic valve replacement or repair), especially for patients with AR resulting from infective endocarditis and aortic root dissection.

Question 17

Briefly describe the treatment for mild to moderate chronic aortic regurgitation

Answer 17

Patients with mild to moderate disease who are asymptomatic with normal LV function do not require treatment and can be reassured; the outcome in these patients is excellent . In patients with this degree of AR severity, symptoms or LV dysfunction, if present, are unlikely to be due to AR. An alternative underlying cause such as hypertension, CAD, or a cardiomyopathy is more likely and should be investigated and treated.

Question 18

Briefly describe the treatment for severe chronic aortic regurgitation

Answer 18

Patients who are asymptomatic are managed according to the stage of their disease:

• Compensated: no treatment is required and the patient can be reassured
• Transitional: no treatment is required and the patient can be reassured unless abnormal haemodynamics in which vasodilator therapy is recommended
• Decomensated: surgery is required

All symptomatic patients require surgery.

Question 19

What are the complications of aortic regurgitation?

Answer 19

• Operative mortality
• Congestive heart failure

Question 20

What differentials should be considered in aortic regurgitation?

Answer 20

1. Mitral regurgitation
2. Aortic stenosis
3. Mitral stenosis

Question 21

How does aortic regurgitation and mitral regurgitation differ?

Answer 21

• Differentiating signs and symptoms: distinguishing signs are right ventricular heave, soft S1, split S2, and aloud P2. The classical murmur of MR is pansystolic at the apex radiating to the axilla.
• Differentiating investigations:
  
  • CXR: pulmonary oedema, enlarged left atrium and left ventricle, and mitral valve calcification
  • ECG: can present with atrial fibrillation.
  • Echocardiography: for MR it is used to assess left ventricular function

Question 22

How does aortic regurgitation and aortic stenosis differ?

Answer 22

• Differentiating signs and symptoms:
  
  • Presentation includes dyspnoea, dizziness, fainting, and congestive cardiac failure
  • Characteristic signs are a slow rising pulse, heaving but undisplaced apex bear, left ventricular heave, and an ejection systolic murmur that radiates towards the carotids and can have an ejection click
• Differentiating investigations:
  
  • CXR: LVH, calcified aortic valve
  • ECG: P-mitrale, LVH with strain pattern, left bundle branch block, or complete AV block
  • Echocardiography: diagnostic for aortic stenosis.

Question 23

How does aortic regurgitation and mitral stenosis differ?

Answer 23

• Differentating signs and symptoms: distinguishing features are a malar flush, low volume pulse, a tapping and undisplaced apex beat, and loud S1 with an opening snap. The murmur is a rumbling mid-diastolic one.
• Differentiating investigations:
  
  • CXR: pulmonary oedema, enlarged left atrium, and mitral valve calcification
  • ECG: can present with atrial fibrillation. RVH may also be present
  • Echocardiography: diagnostic for mitral stenosis