Aortic regurgitation

Question 1

Define aortic regurgitation.

Answer 1

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

Question 2

List the risk factors for aortic regurgitation.

Answer 2

• Bicuspid aortic valve
• Rheumatic fever
• Endocarditis
• Marfan’s and other connective tissue disease - 80% of Marfan’s patients present with diastolic murmur at early age
• Aortitis - e.g. from syphilis, Behcet’s , Takayasu’s, reactive arthritis, ankylosing spondylitis

Question 3

Describe the aortic regurgitation murmur and when it is best heard.

Answer 3

Best heard in aortic area with patient sitting forward and in expiration

• Early diastolic, soft murmur
• S1 is soft
• Absent S2
• +/- S3
• Poor transmission to carotids
• +/- Austin-Flint murmur

Question 4

What is an Austin-Flint murmur and what causes it?

Answer 4

AustIn Flint – Aortic Incompetence

• Caused by Aortic regurgitation
• Blood flows back through aortic valve and over anterior leaflets of mitral valve causing turbulent sound
• Causes a physiological mitral stenosis
• Mid-diastolic murmur
• Heard best at the apex

Question 5

What are the causes of aortic regurgitation?

Answer 5

D eveloping countries: rheumatic fever

Developed countries:

• Aortic root dilation due to connective tissue disorders such as Ehlers Danlos syndrome or Marfan syndrome
• Bicuspid congenital malformation

Question 6

Describe the pathophysiology of acute AR vc chronic AR.

Answer 6

Acute AR is a medical emergency with high mortality and results in (1) an acute rise in left atrial pressure, (2) pulmonary oedema, and (3)cardiogenic shock.

Chronic AR is usually asymptomatic due to compensatory chamber enlargement and hypertrophy but eventually LV systolic dysfunction supervenes and LV end-diastolic pressure rises –> symptomatic congestive heart failure.

Question 7

How common is AR?

Answer 7

• Not as common as AS and MR - ~13% over 55yrs have AR
• No difference based on sex/race.
• Rheumatic disease is commonest cause
• In developed countries, congenital/degenerative valve abnormalities are the most common cause

Question 8

What are the presenting symptoms of aortic regurgitation?

Answer 8

Asymptomatic for decades then:

• Dyspnoea
• Fatigue
• Weakness
• Orthopnoea
• Paroxysmal nocturnal dyspnoea
• Decreased urine output

Question 9

What are the signs of aortic regurgitation on physical examination?

Answer 9

• Early diastolic, soft murmur
• Corrigan’s/collapsing pulse - bounding and forceful, rapidly increasing and subsequently collapsing
• Corrigan’s sign - visible pulsations on neck
• 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
• Wide pulse pressure

Other:

• Mottled extremities (blotchy) - cardiogenic shock
• Cyanosis
• Tachypnoea
• Displaced apex - LVH
• Basal lung crepitations - pulmonary oedema
• Raised JVP

Question 10

What investigations should you do to confirm aortic regurgitation?

Answer 10

• ECG
• CXR
• Echocardiogram
• M-mode and 2D imaging
• Colour flow Doppler
• Pulsed wave Doppler
• Continuous wave Doppler

Other: exercise stress test, cardiac catheterisation, MRI, radionucleotide angiography.

Question 11

What would an ECG show in aortic regurgitation?

Answer 11

ECG - only supportive evidence but need echocardiography to confirm AR.

• Chronic severe AR –> specific ST wave changes, LVH and left axis deviation due to compensatory chamber enlargement , LV conduction delays
• Acute AR –> non-specific ST changes, sinus tachycardia or arrhythmias, evidence of myocardiac ischaemia may also be present.

Paravalvular abscesses in infective EC –> conduction abnormalities

Question 12

What does an echocardiogram show in AR?

Answer 12

• DIAGNOSTIC
• Asseses severity
• Shows origin of regurgitant jet and its width
• Detection of cause of aortic valve pathology

Question 13

What does cardiac cathterisation show?

Answer 13

Used to evaluate

• coronary artery disease
• severity of lesion
• anatomy of aortic root
• LV function
• other valve disease

Used when echocardiogram is inconclusive

Question 14

What is the difference between eccentric and concentric hypertrophy of the heart?

Answer 14

• Concentric hypertrophy is associated with increased left ventricular wall thickness
• Eccentric hypertrophy is characterized by dilatation of the left ventricular chamber

Question 15

Summarise the common valvular pathologies (buzzwords).

Answer 15

Question 16

What does the cooing dove murmur indicate in AR?

Answer 16

Aortic valve collapse and incompetence → “cooing dove” sound + requires urgent valve replacement

Question 17

What does luetic AR mean?

Answer 17

As a result of syphilis

Question 18

What are the causes of AR?

Answer 18