MI and Ischaemic Heart Disease Flashcards
What is chronic angina?
Demand led ischaemia of the heart muscle due to a fixed stenosis
What is the recommendation for patients who have an angina attack and have stable angina?
Stop ,sit and use GTN spray
When may angina commonly be felt?
- after a meal
- in cold air
Where does pain for angina commonly radiate?
- Jaw
- Back
- Epigastrium
- Left (and right) arm
What type of pain is felt with angina?
Heavy crushing pain with tightness
What are the two types of acute MI?
- STEMI
2. NON-STEMI
Why does acute coronary syndrome occur?
Development of an atheromatous plaque that develops a thrombosis and ruptures
Which steps lead to thrombosis occurring?
- Normal
- Fatty streak
- Atherosclerotic plaque
- Fibrous plaque
- Rupture/ thrombosis
In what ways is chronic stable angina different to an acute coronary syndrome such as unstable angina?
- it has a fixed stenosis (not complete occlusion)
- Demand led ischaemia (not supply led)
- Predictable
- Safe
What are the three sub-stages of thrombosis formation?
- Initiation
- Adhesion
- Activation
Describe the imitation stage of thrombosis formation
There is vascular damage exposing the sub- endothelium, collagen and von Willebrand factor
Describe the adhesion stage of thrombosis formation
Platelets recruit to the area and bind to the exposed collagen and von Willebrand factor forming a monolayer
Describe the activation stage of thrombosis formation
- platelets become activated after adhesion and change shape from discs to star-like shapes
- Platelets release ADP and thromboxane A2 (generated by cyclooxyrgenase)
- ADP binds to receptors on circulating platelets allowing more activation to occur
- Activated platelets express adhesion sites for leukocytes (P-selectin and CD40 ligand)
- These processes contribute to the platelet cascade which causes acceleration of platelets activation and coagulation
What is the consequence of intraluminal coagulation ?
Vascular blockage
Hence MI, stroke and death are all possible
What are the key symptoms of MI?
- Severe crushing (10/10) pain not relived by GTN and lasting a long time
- Pain occurs at rest
- Pain radiated to jaw, left (and right) arm, back and epigastric region