10. Angina Flashcards
What are the different types of angina and how do they arise?
Stable angina - result of coronary artery disease
Unstable - result of e.g. acute myocardial infarction
What is the most important diagnostic tool for angina and why (what are you looking for)?
Patient history i.e. what they tell you - necessary to correctly diagnose angina
Looking for a central chest pain that comes on following exertion but is no longer present at rest
This pain may be worse following a meal
What is the cause of angina and how can it arise?
The cause is generally coronary artery disease
Essentially, angina is a manifestation of ischaemia i.e. an imbalance between myocardial oxygen supply and myocardial oxygen demand
What can cause a reduction in myocardial oxygen supply?
Coronary artery disease i.e. atherosclerosis, coronary spasm where the arteries go into spasm
Severe anaemia
What might cause an increase in myocardial oxygen demand?
Left ventricular hypertrophy resulting from hypertension, aortic stenosis, aortic regurgitation
Right ventricular hypertension resulting from pulmonary hypertension, pulmonary stenosis
Rapid tachyarrhythmias - a very fast heart rate means that the heart is beating too fast for the supply of O2 to cope with
What is meant by ‘pulmonary hypertension’? (as opposed to hypertension)
Increased blood pressure in the pulmonary artery, pulmonary vein or pulmonary capillaries i.e. the lung vasculature
Can lead to shortness of breath, dizziness, fainting
How can you diagnose angina from chest pain (not including diagnostic testing)?
When the patient exercises/stresses the heart, the pain should manifest but then is not present when the patient is resting (indicative of coronary heart disease)
This is the most important way to diagnose angina
What diagnostic tests can be used to confirm a diagnosis of angina?
Perfusion imaging - inadequate perfusion to the heart
LV wall motion - the heart will stop contracting due to a lack of O2
ECG - look at changes on here compared to their normal ECG
Anatomical imaging is becoming more popular - can see an image of the coronary arteries and can see whether or not they are obstructed
CT coronary angiography (NICE guideline)
Describe the character, location, radiation, duration and provocation of angina
Character - tight, restricting discomfort
Location - across the chest
Radiation - into the arms, throat or jaw
Duration - lasts only 5 to 10 minutes at the most
Provocation - must be provoked by exertion and be eased by rest to be angina
How can angina present on an ECG?
Resting ECG will be normal
Exercise ECG will most likely show an ST depression - this is indicative of iscaemia
How can you treat angina (briefly)?
Drug treatment is very effective and provides symptomatic relief - can either be used to increase O2 delivery or to reduce the O2 demand
Surgery
Lifestyle modifications
What drugs can be used to increase oxygen delivery to the heart and why?
Two main drugs:
Nitrates - cause vasodilation of the coronary arteries
Calcium channel blockers (vasodilation of the coronary arteries)
If a patient had an adverse reaction to these drugs then e.g. nicorandil and revasc may be used
What drugs can be used to reduce the oxygen demand of the heart and why?
Two decrease heart rate - beta blockers
Decrease left ventricle wall tension - beta blockers, nitrates, calcium channel blockers
Reduce contractility - beta blockers, calcium channel blockers
SO what is the main drug treatment for angina?
Beta blockers or calcium channel blockers
What should also be prescribed, along with beta blockers and calcium channel blockers and why?
Some form of glyceryl trinitrate (GTN) to put under the tongue
Very effective at aborting angina attacks
Nitrate - vasodilator
