Angina Flashcards
What are the 5 different types of angina?
1) Angina of effort/primary angina
2) Mixed (variable threshold) angina
3) Vasospastic (Prinzmetal’s)
4) Microvascular (syndrome X)
5) Unstable
Which two types of angina are due to low oxygen supply?
Vasospastic and unstable
What are the symptoms of primary angina?
Tightness, squeezing, crushing sensation in chest
What is the most common form of angina?
Primary angina/angina on exertion
When does primary angina develop?
With stenosis of < 70% of coronary arteries
What causes/what are the features of primary angina?
- Due to exertion/emotion
- Stops with rest or GTN
- Results from high oxygen demand with restricted blood flow, due to fixed stenosis
What happens in primary angina?
Low oxygen in cardiac tissue → release of protons and bradykinin → activation of TRPV1 on sensory nerves → pain and release of substance P (attempt at compensatory mechanism) → coronary vasodilation
Why does coronary vasodilation not help primary angina?
Because it doesn’t dilate stenosis
Describe mixed (variable threshold) angina
- Unpredictable
- Develops at different levels of exercise
- Probably due to stenosis and vasospasm
- Though to be v common
- Bc spasm is involved, vasodilator might help
Describe vasospastic (Prinzmetal’s) angina
- Due to spasm of coronary artery
- Occurs at rest, often at night
- Unpredictable
- Quite rare
Describe microvascular (syndrome X) angina
- Chest pain
- Normal coronary angiogram
- Positive exercise test
- Endothelial dysfunction
- Microvasculature is constricted → so due to over-constriction of microvasculature in coronary circulation
- Occurs more commonly in women
Describe unstable angina
- Due to transient formation of a non-occlusive thrombus
- An acute coronary syndrome → called angina bc it involves chest pain
