Stable Angina - Diagnosis, Investigations and Management Flashcards
Define angina.
Angina = pain, but it has been adopted to mean cardiac chest pain (angina pectoris).
It is a discomfort in the chest and/or adjacent areas associated with myocardial ischaemia but without myocardial necrosis.
Why does angina result from myocardial ischaemia?
Mismatch of oxygen supply and metabolites to myocardium and myocardial demand for them.
How might blood flow to the myocardium be restricted?
Obstructive coronary atheroma (v. common)
Coronary artery spasm (uncommon)
Coronary inflammation/arteritis (v. rare)
What might cause mismatch of delivery of oxygen and nutrients to the myocardium and the demand for them?
Reduced blood flow to the myocardium (most commonly)
Uncommonly due to reduced oxygen transport, e.g. anaemia
Uncommonly due to pathologically increased myocardial oxygen demand.
Give pathological situations where there would be an increased oxygen demand in the myocardial tissue?
Left ventricular hypertrophy (LVH) - seen in persistent hypertension, significant aortic stenosis and hypertrophic cardiomyopathy.
Thyrotoxicosis
What is the most common cause of angina?
Coronary atheroma.
Why does the patient only feel symptoms during excretion with stable angina?
On activity the increased myocardial oxygen demand obstructed by coronary blood flow leads to myocardial ischaemia and symptoms of angina, which result with rest as oxygen demand returns to normal.
In which situations does myocardial oxygen demand increase?
Any situation where HR and BP increase, e.g. exercise, anxiety/emotional stress and even after a large meal, cold weather.
How will patients typically show where the pain is? And how do they describe the pain?
Use hand to clutch over retrosternal area.
A tight band, or like a weight pushing on their chest. ON exertion.
How much occlusion of the coronary arteries is necessary to experience angina?
> 70% lumen occlusion by obstructive plaque.
How does the appearance of the coronary arteries differ in stable angina in comparison with acute coronary syndromes?
In stable angina, a fatty streak has developed into an atherosclerotic plaque. In ACSs there is spontaneous place rupture than leads to thrombosis formation leading to different degrees of occlusion.
What important things should you establish about the angina to make sure it is not a different cause of chest pain? i.e. what are the features making stable angina likely?
Site of pain - retrosternal
Character of pain - often tight band, pressure, heaviness
Radiation sites - neck and onto jaw and down arms
Aggregating factors - exerction, stress and relieving factors - improve with GTN rapidly or physical rest.
What features would make the diagnosis of stable angina less likely?
Sharp/stabbing pain, pleuritic or pericardial
Associated with body movements or positions
Very localised, pinpoint site
Superficial w/ or w/o tenderness.
No pattern to pain, particularly if occurring at rest
Begins some time after exercise
Lasts for hours
What are other possible differentials for chest pain?
Cardiovascular causes - aortic dissection (tearing, causes unremitting pain at rest), pericarditis (better when lying back , sharp stabbing pain)
Respiratory causes - pneumonia, pleurisy, peripheral pulmonary emboli (pleuritic)
Musculoskeletal causes - cervical disease, costochrondritis, muscle spasm or strain
GI causes - gastro-oesphageal reflux, oesophageal spasm, peptic ulceration, biliary colic, cholecystitis, pancreatitis
Very occasionally myocardial ischaemia present with no chest pain, what other symptoms might a patient present with that could point towards myocardial ischaemia? What kind of patients are most likely to present like this?
SoB on exertion
Excessive fatigue on exertion
Near syncope on exertion
Elderly or patients with diabetes mellitus probably due to reduced pain sensation.
How is the severity of stable angina assessed?
Canadian classification of angina severity.
What are the four stages of severity of stable angina?
I - ordinary physical activity does not cause angina, symptoms only on significant exertion.
II - slight limitation of ordinary activity, symptoms on walking 2 blocks or up more than one flight of stairs.
III - marked limitation, symptoms on walking only 1-2 blocks or 1 flight of stairs.
III - symptoms on any activity, getting washed/dressed etc.
What are some non-modifiable risk factors for coronary artery disease?
Age, gender (make more susceptible), creed, family history and genetic factors.
What are some modifiable risk factors for coronary artery disease?
Smoking, diet and exercise, diabetes mellitus (glycaemic control reduces CV risk), hypertension (BP control reduces risk), hyperlipidaemia (lowering reduces risk).
