Stable Angina Flashcards
What is stable angina?
A discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis usually brought on from exercise.
How much of the lumen must be obstructed for patient to have stable angina and to have symptoms?
> 70%
What is the difference between stable angina and acute coronary disease?
stable angina
- symptoms only on exertion or when heart rate increases (emotion, stress)
- plaque formation is a progressive process and may take a long time to develop
ACD
- symptoms can be a rest
- spontaneous plaque rupture or local thrombosis which causes lumen occlusion.
The symptoms of stable angina are caused by the mismatch of the supply of oxygen and the demand for oxygen.
Occlusion of the lumen from plaque or thrombosis is the most common way but there are other uncommon ways for the oxygen mismatch to occur.
Names some uncommon ways this can happen.
- arterial spasm
- arterial inflammation
-anaemia which reduces transport of O2
- LVH which increases demand for O2 as there is more muscle
- Thyrotoxicosis - hyper metabolic state so there is higher demand for O2
Name the four stages of angina pectori
increased myocardial oxygen demand
obstructed coronary blood flow
myocardial ischaemia
symptoms of angina
What is the characteristics of pain with angina? site? character? radiation sites? relieving factors?
- Site of pain (watch for patient gestures): retrosternal
- Character of pain: often tight band/pressure/heaviness.
- Radiation sites: neck and/or into jaw, down arms.
- Aggravating e.g. with exertion, emotional stress
- Relieving factors e.g. rapid improvement with GTN or physical rest.
Which patient may not have symptoms of angina because they have reduced pain sensation?
Elderly and diabetes mellitus patients
Which symptoms are less likely to be angina
- Sharp/‘stabbing’ pain; pleuritic or pericardial.
- Associated with body movements or respiration.
- Very localised; pinpoint site.
- Superficial with/or without tenderness.
- No pattern to pain, particularly if often occurring at rest.
- Begins some time after exercise.
- Lasting for hours.
Name some differential diagnosis.
cardiovascular
respiratory
musculoskeletal
GI
• Cardiovascular causes:
o Aortic dissection (intra-scapular “tearing”), pericarditis
• Respiratory:
o Pneumonia, pleurisy, peripheral pulmonary emboli (pleuritic)
• Musculoskeletal:
o Cervical disease, costochondritis, muscle spasm or strain
• GI causes:
o Gastro-oesphageal reflux, oesophageal spasm, peptic ulceration, biliary colic, cholecystitis, pancreatitis
Canadian Classification
There are four severities of angina
How are they classified ?
I Symptoms only on significant exertion.
II Slight limitation of ordinary activity, symptoms on walking 2 blocks or > 1 flight of stairs.
III Marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs.
IV Symptoms on any activity, getting washed/dressed causes symptoms.
Risk factors of angina
Non modifiable and modifiable
Non-modifiable
• Age, gender, creed, family history & genetic factors.
Modifiable
• Smoking
• Lifestyle - exercise & diet
• Diabetes mellitus (glycaemic control reduces CV risk)
• Hypertension (BP control reduces CV risk)
• Hyperlipidaemia (lowering reduces CV risk)
What could you see on examination of a patient with angina?
- Tar stains on fingers (not nicotine stains)
- Obesity (centripedal)
- Xanthalasma and corneal arcus (hypercholesterolaemia)
- Hypertension
- Abdominal aortic aneurysm arterial bruits, absent or reduced peripheral pulses.
- Diabetic retinopathy, hypertensive retinopathy on fundoscopy.
Name some associated clinical signs of angina.
- Pallor of anaemia
- Tachycardia, tremor, hyper-reflexia of hyperthyroidism
- Ejection systolic murmur, plateau pulse of aortic stenosis
- Pansystolic murmur of mitral regurgitation
- Signs of heart failure such as basal crackles, elevated JVP, peripheral oedema.
Investigations that should be done for angina.
Bloods -FBC, lipid profile, fasting Glc, liver/thyroid tests
CXR- show causes of chest pain, pulmonary oedema
ECG- usually normal, prior MI=Q waves, LVH=ST depression
ETT (exercise tolerance test)- only works if person can work hard enough to raise HR, ST depression = + test
Myocardium Perfusion Imaging- radioactive substance is injected before stress and before and after stress is compared to show the changes of the arteries.
• Tracer seen at rest but not after stress = ischaemia (Blood flow shortage)
• Tracer seen neither rest, or after stress = infarction (Blocked blood flow)
CT of coronary arteries- not defining for angina but shows anatomy of the coronary arteries
Invasive angiography- dye is injected into coronary arteries, clear diagnosis, done in young cardiac patients due to life/work or with an early and strongly positive ETT.
Describe Treatment strategies
- general measures
- medical measures
- influences disease progression
- relief symptoms
- Revascularisation
- Address risk factors- lifestyle (smoking, exercise, diet), cholesterol, BP
- a) Statins: consider if total cholesterol >3.5 mmol/l.
Reduce the LDL-cholesterol deposition in atheroma and also stabilise atheroma reducing plaque rupture and ACS.
ACE inhibitors: if increased CV risk and atheroma
Stabilise endothelium and also reduce plaque rupture.
Reduces angiotensin II
Aspirin; 75mg or clopidogrel if intolerant of aspirin.
May not directly affect plaque but does protect endothelium and reduces of platelet activation/aggregation
b) ß-blockers; achieve resting HR
CCB
Ik channel blockers
Revascularisation
- if symptoms aren’t controlled
