Cardio - Aortic Regurgitation

Question 1

describe the symptoms caused by chronic aortic regurgitation. explain why these occur.

Answer 1

Symptoms only occur later in disease as LV compensates up to a certain extent. Involve symptoms of congestive heart failure:

1. LHF Sx related to low CO, e.g. dyspnoea, fatigue, weakness
2. RHF Sx, e.g. peripheral oedema
3. Palpitations as a result of large stroke volume and forceful LV contractions
4. Angina as low diastolic pressures compromise coronary filling and LV hypertrophy increases O2 demand

Question 2

What type of murmur can be heard on auscultation in AR?

Answer 2

• early diastolic decrescendo murmur
• best heard with pt leaning forwards, on expiration
• at left 3rd IC space (Erb’s point) or right upper sternal border if aortic root disease
• S3 often present due to increased early diastolic filling into a compliant, dilated left ventricle

Question 3

Describe the pulse rate/rhythm/character of a pt with AR

Answer 3

• normal rate, sinus rhythm

- collapsing, high volume

Question 4

What might be felt on palpation in a pt with AR?

Answer 4

• PMI moved inferolaterally (due to LVD), volume-loaded

Question 5

Name 3 traditional (rare today) signs of AR

Answer 5

1. Corrigan’s sign (visible bounding carotid pulse)
2. De Musset’s (head bobbing)
3. Quincke’s sign (visible nailbed pulsation)

Question 6

Describe 2 types of aetiology for AR

Answer 6

1. Aortic leaflet abnormalities
   - infection: chronic rheumatic fever (most common cause world-wide), infective endocarditis (vegetation prevents proper valve closure)
   - degenerative: bicuspid aortic valve calcification, senile calcification
   - inflammatory: SLE, RA
   - other: transcatheter aortic valve replacement
2. Aortic root abnormalities (cause stretching of aortic valve annulus)
   - aortic root dilatation: Marfan’s syndrome, Ehlers-Danlos syndrome, idiopathic aortitis
   - loss of commissural support

Question 7

What are the downstream pathological consequences of AR?

Answer 7

1. Increased LV volume… LV dilation and eccentric hypertrophy… increased systolic pressure (to maintain CO)
2. Decreased aortic volume… decreased diastolic pressure… widened pulse pressure / hyperdynamic circulation
3. Increased workload on heart results in congestive heart failure

Question 8

Which investigations would you perform in someone with suspected AR?

Answer 8

1. Echocardiography: confirms presence of AR and assesses severity.
2. Cardiac magnetic resonance or multi-slice CT: recommended for assessment of aorta in pts with Marfan’s or if enlarged aorta is detected by echo, esp. in pts with bicuspid valve.
3. Cardiac catheterisation: used to assess coronary anatomy before surgery in pts with appropriate age and risk factor profile in whom non-invasive imaging is inconclusive.

Other:

• CXR - may show cardiac enlargement in chronic AR and pulmonary oedema in acute AR. Mediastinum may appear widened if AR due to aortic dissection.
• ECG - sinus tachy may be present in acute AR due to increased SNS tone

Question 9

Which drugs would you recommend for a pt with Marfan’s to slow aortic root dilation?

Answer 9

B-blockers

Question 10

In which pts is surgical therapy used and what are the 2 options for this?

Answer 10

Used in symptomatic pts or asymptomatic pts with deteriorating LV function (high risk of developing irreversible myocardial dysfunction).

1. aortic valve replacement - most widely used technique, can be combined with replacement of aorta and re-implantation of coronary arteries if associated aneurysm of aortic root
2. valve-sparing aortic replacement - increasingly used in expert centers, esp. in younger pts. improved long-term survival and reduced risk of aortic insufficiency and thromboembolic complications

Question 11

Suggest possible complications of AR

Answer 11

1. congestive heart failure - due to LV dilation/hypertrophy
2. collapse of aortic valve (rare) - becomes completely incompetent, requires urgent replacement
3. infective endocarditis
4. sudden death
5. MI
6. arrhythmias