1
Q
Define Aortic Stenosis
A
Obstruction of left ventricular outflow due to narrowing at the level of the aortic valve
2
Q
Explain the aetiology/risk factors for aortic stenosis
A
- Senile degeneration (over 70) of the aortic valve due to calcification (80% of cases) -
- this is said to be due to high pressure/turbulent flow across the valve which stimulates an inflammatory procedure leading to calcium deposition. So risk factors for degeneration include:
- Hypertension
- Smoking
- Diabetes
- High LDL cholesterol
- this is said to be due to high pressure/turbulent flow across the valve which stimulates an inflammatory procedure leading to calcium deposition. So risk factors for degeneration include:
- Calcification of congenital bicuspid aortic valve
- Rheumatic fever
- Chronic Kidney disease
3
Q
Summarise the epidemiology of aortic stenosis
A
- Present in 3% of 75 year olds
- More common in males
- Those with bicuspid aortic valve present earlier
4
Q
Recognize the presenting symptoms of aortic stenosis
A
- May be ASYMPTOMATIC to start, once symptoms start mortality drops significantly
CLASSIC TRIAD:
- Exertional dyspnoea (most common)
- Chest pain on exertion/angina (may occur in the absence of coronary atherosclerotic disease)
- Syncope
5
Q
Recognise the signs of aortic stenosis on physical examination
A
- Ejection-systolic murmur that radiates to carotids bilaterally
- Loudest at the right upper sternal border
- S2 may grow fainter the more severe it becomes due to decreased mobility of the aortic valve leaflets and single S2 is heard due to delayed aortic valve closing (A2)
- In severe AS, S2 is split due to delayed aortic valve closure such that A2 comes after P2 (paradoxical split)
- Ejection click may be heard due to pliability of bicuspid valve upon coming into contact with ejected stream.
- S4 may be present due to LVH
- Increases on expiration and diminished with hand grip –> increased afterload –> decreased LV-Aorta pressure gradient
- Valsalva manoeuvre increases intra-thoracic pressure (e.g. straining for a poo/puff cheeks up, close nose and try to exhale) by trying to expire against a closed epiglottis. This positive pressure reduces preload/venous return so reduces most murmurs including AS but increases HOCM
- Pulsus tardus et parvus (late/after S1 and faint) carotid upstroke (Slow-rising pulse)
- Heaving, undisplaced apex beat (due to LVH)
- Thrill in the aortic area
6
Q
Identify appropriate investigations for aortic stenosis and interpret the results
A
Transthoracic Echocardiogram – diagnostic
- Estimation of the pressure gradient across the valve in systole
- Can estimate LV ejection function
ECG
- The main feature this will show is LVH and absent Q waves:
- Deep S in V1/V2 and Tall R in V5/6
- LBBB or complete AV block
Cardiac angiography
- Allows differentiation from other causes of angina (e.g. MI) or assessment of concomitant coronary artery disease
