SIHD and Angina Flashcards
What is angina (pectoris)?
Cardiac chest pain: a discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis
What causes angina?
A mismatch between oxygen supply and metabolites to the myocardium and the demand for them
What is the cause for the mismatch between oxygen/metabolite supply and the demand?
A reduction in the coronary blood flow to the myocardium, most commonly caused by obstructive coronary atheroma
What are the less common causes of angina@
Anaemia and increased myocardial demand (Left ventricular hypertrophy and thyrotoxicosis)
At what times will myocardial oxygen demand increase?
During exercise, anxiety/emotional stress, cold weather and after a large meal
What are the characteristics of angina?
Site: retrosternal
Character: tight band/pressure
Radiation: neck, jaw and arms
Exacerbating Factors: exertion, emotional stress etc.
Relieving Factors: rapid improvement with GTN or physical rest
What features of the pain make angina unlikely?
Pain that is sharp/stabbing, associated with body movements, very localised, superficial, without pattern, begins some time after exercise or lasts for hours
Besides chest pain, what other symptoms may myocardial ischaemia present with on exertion?
Breathlessness, excessive fatigue and near syncope
What does stage 1 on the CCS scale of angina severity represent?
Symptoms are only on significant exertion
What does stage 2 on the CCS scale of angina severity represent?
Slight limitation of ordinary activity. Symptoms on walking 2 blocks or more than one flight of stairs
What does stage 3 on the CCS scale of angina severity represent?
Marked limitation. Symptoms on walking 1-2 blocks or 1 flight of stairs
What does stage 4 on the CCS scale of angina severity represent?
Symptoms on any activity - getting washed/dressed causes symptoms
What are the non-modifiable risk factors for coronary artery disease
Age, gender, creed, family history and genetic factors
What are the modifiable risk factors for coronary artery disease?
Smoking, lifestyle - exercise and diet, diabetes mellitus (control reduces risk), hypertension (control reduces risk) and hyperlipidaemia (lowering reduces risk)
What are the signs that help diagnose stable angina?
Tar staining, obesity, xanthalasma, corneal arcus, hypertension, abdominal aortic aneurysm bruits, absent or reduced peripheral pulses, diabetic/hypertensive retinopathy
What sign would you expect to see if anaemia was an exacerbating/associated condition?
Pallor
What sign would you expect to see if hyperthyroidism was an exacerbating/associated condition?
Tachycardia, tremor and hyper-reflexia
What sign would you expect to see if aortic stenosis was an exacerbating/associated condition?
An ejection systolic murmur and plateau pulse
What sign would you expect to see if heart failure was an exacerbating/associated condition?
Basal crackles, pansystolic murmur of mitral regurgitation elevated JVP and peripheral oedema
What blood tests would be routinely done for someone with suspected angina?
FBC, lipid profile, fasting glucose, electrolytes, liver and thyroid tests
Why might a CX-Ray be done?
It often helps show other causes of chest pain and pulmonary oedema
What may be seen on the ECG?
Evidence of prior MI e.g. pathological Q waves or evidence of LVH e.g. high voltages, lateral ST segment depression or ‘strain pattern’
What investigations can be used to diagnose stable angina?
ECG, exercise tolerance test, CT coronary angiography and myocardial perfusion imaging
What comparison does myocardial perfusion imaging allow?
It allows comparison between the images taken at rest and during stress
During myocardial perfusion imaging, what does seeing the tracer at rest but not after stress suggest?
Ischaemia
What does not seeing the tracer at rest or during stress on myocardial perfusion imaging suggest?
That there are areas of infarction
Under what circumstances would an invasive angiography be performed?
If there is an early or strongly positive ETT, angina refractory to medical therapy, the diagnosis is not clear after non-invasive tests, they are a young cardiac patient due to work/life effects or they have a high risk occupation/lifestyle e.g. drivers
How is a coronary angiogram performed?
It is mostly done under a local anaesthetic. A cannula is passed into the femoral/radial artery and the coronary catheters are passed to the aortic root. They are then introduced into the ostium of the coronary arteries and radio-opaque contrast is injected down the coronary arteries and visualised on X-Ray
What are the treatment strategies for stable angina?
Address the risk factors (BP, cholesterol etc.), medical treatment (drugs to reduce disease progression and symptoms) and revascularisation (PCI and CABG) if the symptoms are not controlled
What types of medications are used to reduce the disease progression?
Statins (if cholesterol levels are high), ACE inhibitors (if increased CV risk and atheroma) and aspirin
What medications are used to relieve the symptoms of stable angina?
Beta-blockers, CCBs, and Ik channel blockers lower heart rate to <60bpm.
CCBs and nitrates (GTN) produce vasodilation.
Potassium channel blockers helpful in ‘pre-conditioning’
How does PCI work?
It uses a balloon and stent to squash the atheromatous plaque into the walls and open the artery
What drugs should be prescribed if a stent has been used?
Aspirin and clopidogrel taken together
Which patients are more likely to have prognostic benefit from CABG?
Those with: >70% stenosis of the left mains stem artery, significant proximal three vessel coronary artery disease or two vessel coronary artery disease that includes significant stenosis of the proximal left anterior descending coronary artery and who have ejection fraction <50%
