Aortic Stenosis

Question 1

Defintion

Answer 1

Narrowing of the left ventricular outflow at the level of the aortic valve

Question 2

Aetiology/risk factors

Answer 2

· Stenosis can be secondary to rheumatic heart disease (MOST COMMON WORLDWIDE)

· Calcification of a congenital bicuspid aortic valve

· Calcification/degeneration of a tricuspid aortic valve in the elderly

Question 3

Epidemiology

Answer 3

· Present in 3% of 75 yr olds

· More common in males

· Those with bicuspid aortic valve present earlier

Question 4

Presenting symptoms

Answer 4

· May be ASYMPTOMATIC initially

· Angina (due to increased oxygen demand of the hypertrophied left ventricle)

· Syncope or dizziness on exercise (due to outflow obstruction)

· Symptoms of heart failure (e.g. dyspnoea, orthopnoea)

Question 5

Signs on physical examination

Answer 5

· Narrow pulse pressure
· Slow-rising pulse
· Thrill in the aortic area (only if severe)
· Forceful sustained thrusting undisplaced apex beat
· Ejection systolic murmur at the aortic area, radiating to the carotid artery
· Second heart sound may be softened or absent (due to calcification)
· A bicuspid valve may produce an ejection click

Question 6

Investigations

Answer 6

· ECG
o Signs of left ventricular hypertrophy
· Deep S in V1/2
· Tall R in V5/6
· Inverted T waves in I, aVL and V5/6
· Left axis deviation
o LBBB (left bundle branch block)

· CXR
o Post-stenotic enlargement of ascending aorta
o Calcification of aortic valve

· Echocardiogram
o Visualises structural changes of the valves and level of stenosis (valvar, supravalvar or subvalvar)
o Estimation of aortic valve area and pressure gradient across the valve in systole
o Assess left ventricular function

· Cardiac angiography
o Allows differentiation from other causes of angina (e.g. MI)
o Allows assessment of concomitant coronary artery disease
· NOTE: 50% of patients with severe aortic stenosis have significant coronary artery disease