Question 116#

A 71-year-old man who had a bioprosthetic aortic valve replacement three years ago is reviewed.

What antithrombotic therapy is he likely to be taking?

A. Nothing

Correct Answer B:

Prosthetic heart valves - antithrombotic therapy:

• Bioprosthetic: aspirin
• Mechanical: warfarin + aspirin

Prosthetic heart valves:

The most common valves which need replacing are the aortic and mitral valve. There are two main options for replacement: biological (bioprosthetic) or mechanical.

Following the 2008 NICE guidelines for prophylaxis of endocarditis antibiotics are no longer recommended for common procedures such as dental work.

Question 117#

Which one of the following conditions is most associated with aortic dissection?

A. Acromegaly

Correct Answer D:

A bicuspid aortic valve increases the risk of aortic dissection six-fold.

Aortic dissection:
Stanford classification:

• Type A - ascending aorta, 2/3 of cases
• Type B - descending aorta, distal to left subclavian origin, 1/3 of cases

DeBakey classification:

• Type I - originates in ascending aorta, propagates to at least the aortic arch and possibly beyond it distally
• Type II - originates in and is confined to the ascending aorta
• Type III - originates in descending aorta, rarely extends proximally but will extend distally

Associations:

• Hypertension
• Trauma
• Bicuspid aortic valve
• Collagens: Marfan's syndrome, Ehlers-Danlos syndrome
• Turner's and Noonan's syndrome
• Pregnancy
• Syphilis

Complications of backward tear:

• Aortic incompetence/regurgitation
• MI: inferior pattern often seen due to right coronary involvement

Complications of forward tear:

• Unequal arm pulses and BP
• Stroke
• Renal failure

Question 118#

Which of the following congenital heart defects is associated with a bicuspid aortic valve?

A. Tetralogy of Fallot

Correct Answer D:
Bicuspid aortic valve:

Overview:

• Occurs in 1-2% of the population
• Usually asymptomatic in childhood
• The majority eventually develop aortic stenosis or regurgitation
• Associated with a left dominant coronary circulation (the posterior descending artery arises from the circumflex instead of the right coronary artery) and Turner's syndrome
• Around 5% of patients also have coarctation of the aorta

Complications:

• Aortic stenosis/regurgitation as above
• Higher risk for aortic dissection and aneurysm formation of the ascending aorta

Question 119#

Which of the following conditions is not associated with the development of aortic regurgitation?

A. Rheumatic fever

Correct Answer E:

Dilated cardiomyopathy is associated with the development of mitral regurgitation, not aortic regurgitation.

Aortic regurgitation:

Features:

• Early diastolic murmur
• Collapsing pulse
• Wide pulse pressure
• Mid-diastolic Austin-Flint murmur in severe AR - due to partial closure of the anterior mitral valve cusps caused by the regurgitation streams

Causes (due to valve disease):

• Rheumatic fever
• Infective endocarditis
• Connective tissue diseases e.g. RA/SLE
• Bicuspid aortic valve

Causes (due to aortic root disease):

• Aortic dissection
• Spondylarthropathies (e.g. ankylosing spondylitis)
• Hypertension
• Syphilis
• Marfan's, Ehler-Danlos syndrome

Question 120#

A 67-year-old man with a history of chronic obstructive pulmonary disease and ischaemic heart disease is taken to the Emergency Department with dyspnoea. On examination his respiratory rate is 24 / min, JVP is not elevated and crackles are heard in both lung bases.

Which other finding would most strongly indicate that his dyspnoea is secondary to isolated left ventricular failure?

A. Pulsus alternans

Correct Answer B:

Gallop rhythm (S3) is an early sign of LVF.

Whilst all of the above features may be seen in patients with left ventricular failure a gallop rhythm is one of the most specific and early signs.

Heart sounds:
The first heart sound (S1) is caused by closure of the mitral and tricuspid valves whilst the second heart sound (S2) is due to aortic and pulmonary valve closure.

S1

• Closure of mitral and tricuspid valves
• Soft if long PR or mitral regurgitation
• Loud in mitral stenosis

S2

• Closure of aortic and pulmonary valves
• Soft in aortic stenosis
• Splitting during inspiration is normal

S3

• Caused by diastolic filling of the ventricle
• Considered normal if < 30 years old (may persist in women up to 50 years old)
• Heard in left ventricular failure (e.g. dilated cardiomyopathy), constrictive pericarditis (called a pericardial knock)

S4

• May be heard in aortic stenosis, HOCM, hypertension
• Caused by atrial contraction against a stiff ventricle
• In HOCM a double apical impulse may be felt as a result of a palpable S4