Stable Ischaemic Heart Disease Flashcards
What is the difference between angina and a heart attack?
Myocardiac ischaemia without myocardial necrosis
What is the pathophysiology of myocardial ischaemia and anginal symptoms?
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
What percentage of the lumen is usually obstructed in stable angina?
> 70%
What are is the typical presentation in SIHD?
Retrosternal pain Tight band/crushing chest pain Radiates to neck and/or jaw, down arms Worse on exertion Rest helps
What features may make angina a less likely diagnosis?
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
What are risk factors in SIHD/coronary artery disease?
Non modifiable:
- age
- sex
- family history/genetics
Modifiable:
- smoking
- exercise/diet
- diabetes
- hypertension
- hyperlipidaemia
What investigations might you do in suspected IHD?
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
How might SIHD be scored?
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
How might you treat SIHD?
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
If a stent is placed, what medication is taken after?
Aspirin
Clopidogrel