Stable Ischaemic Heart Disease

Question 1

What is the difference between angina and a heart attack?

Answer 1

Myocardiac ischaemia without myocardial necrosis

Question 2

What is the pathophysiology of myocardial ischaemia and anginal symptoms?

Answer 2

Mismatch between supply of O2 and metabolites to myocardium, and the demand.

Most commonly due to reduction in coronary blood flow caused by:

• obstructive coronary atheroma (common)
• coronary artery spasm (uncommon)
• coronary inflammation/arteritis (rare)

Uncommonly due to pathologically increased myocardial O2 demand such as in LVH and hypertension, aortic stenosis

Question 3

What percentage of the lumen is usually obstructed in stable angina?

Answer 3

> 70%

Question 4

What are is the typical presentation in SIHD?

Answer 4

Retrosternal pain
Tight band/crushing chest pain
Radiates to neck and/or jaw, down arms
Worse on exertion
Rest helps

Question 5

What features may make angina a less likely diagnosis?

Answer 5

Sharp/stabbing pain
Associated with body movements or respiration
Very localised pain
Superficial pain
No pattern to pain
Begins some time after exercise
Lasts for hours

Question 6

What are risk factors in SIHD/coronary artery disease?

Answer 6

Non modifiable:

• age
• sex
• family history/genetics

Modifiable:

• smoking
• exercise/diet
• diabetes
• hypertension
• hyperlipidaemia

Question 7

What investigations might you do in suspected IHD?

Answer 7

ECG
- normal in >50% of cases
CXR
Bloods - FBC, lipid profile, fasting glucose, electrolytes, liver and thyroid tests
ETT
- negative result doesn't exclude
Myocardial perfusion imaging
- superior to ETT, expensive
CT coronary angiogram
Invasive angiogram
- positive ETT
- diagnosis not clear
- young cardiac patients
- lifestyle with risk

Question 8

How might SIHD be scored?

Answer 8

Canadian classification of angina severity (CCS)

I - symptoms only on significant exertion
II - slight limitation of ordinary activity, multiple flights of stairs
III - marked limitation, symptoms on short walks or single flights of stairs
IV - symptoms on any activity e.g. washed/dressed

Question 9

How might you treat SIHD?

Answer 9

Address risk factors

Limit disease progression

• Statins (total cholesterol >3.5mM/L)
• ACEi
• Aspirin

Address symptoms:

• Beta-blockers (target HR <60)
• CCB (vasodilatory and rate limiting)
• Ik channel blockers
• Nitrates
• K+ channel blockers

PCI/CABG

Question 10

If a stent is placed, what medication is taken after?

Answer 10

Aspirin

Clopidogrel