Angina Flashcards
What are the factors affecting the heart’s energy status and viability?
Coronary artery blood flow, sympathetic nerves, peripheral arterioles (afterload), and central venous pressure (preload)
What is angina pectoris?
It is chest pain due to reduced coronary blood flow and is a symptom of IHD
How do drugs reduce angina? What are the 2 ways?
By decreasing HR = less energy consumption of the heart
By vasodilation = reduced preload and afterload = less work done by the heart
What are the 3 types of angina?
Stable, unstable, and variant
What is stable angina?
There’s a stable atheroma (blockage in coronary) in the coronary artery but there is no risk of rupturing and thrombosis. It only occurs when the blood flow cannot meet cardiac demand (exercise).
What is unstable angina?
There’s an atheroma that can fissure, which can cause thrombosis and fully block the coronary artery.
What is variant angina?
It is caused by vasospasm. There is no atheroma to treat.
What is the aim for drug treatment for stable angina?
We must decrease HR = less O2 demand & decrease preload and afterload = less work done by the heart
What is the drug treatment for stable angina? (There’s 5)
- Long-acting nitrates reduces preload (but tolerance can develop, use intermittently) by being de-nitrates in the blood = produces NO = SM muscle relaxation
- CCBs reduce afterload and some (verapamil and diltiazem) also have negative inotropic effects = less ventricular work = less O2 demand
- Beta-blockers have negative ino- and chronotropic effects = less energy needed
- Ivabradine slows SA node rate = slows HR
- Trimetazidine causes ATP production to happen via glucose oxidation instead of fatty acid oxidation
Vasodilation does not work in alleviating stable angina
What is the drug treatment for unstable angina?
- Uses nitrates, b-blockers, and CCBs too
- Aspirin is used as prophylaxis against thrombosis (low dose)
What is the drug treatment for variant angina?
Use coronary artery dilators and nitro-glycerin
