Lecture 2: ACS Flashcards
What happens in the first step of the ACS cascade?
Destabilization and rupture of plaque by shearing forces of blood flow
What happens in the second step of the ACS cascade?
Plaque breaks off and collagen becomes exposed, triggering an immune response causing platelets to try to block it
What happens in the third step of the ACS cascade?
Platelets adhere to collagen and activates to try to form a clot
What happens in the fourth step of the ACS cascade?
Platelets release thromboxin A2 and ADP
What happens in the fifth step of the ACS cascade?
- Release of chemicals triggers activation of P2Y12 receptor
- ADP binds to P2Y12 receptor causing activation of GP2b/3a receptor
What happens in the sixth step of the ACS cascade?
Activation of GP2b/3a receptor causes platelets to crosslink fibrinogen
What happens in the seventh step of the ACS cascade?
Platelets aggregate due to release of TxA2, serotonin, thrombin, and epinephrine
What happens in the eighth step of the ACS cascade?
Fibrinogen is converted to fibrin
What are 3 characteristics of red clots?
- Less platelets and more fibrin
- Complete occlusion
- STEMI
What are 3 characteristics of white clots?
- More platelets and less fibrin
- Incomplete occlusion
- NSTEMI
How can stable angina and ACS be differentiated?
- Symptoms of stable angina are short and go away with rest
- Symptoms of ACS are long and persistent
Briefly describe the 8 steps of the ACS cascade
1) Rupture of plaque
2) Exposed collagen
3) Platelets adhere and activate
4) Platelets release TxA2 and ADP
5) P2Y12 and GP2b/3a activation
6) Fibrinogen crosslink
7) Platelet aggregation
8) Fibrinogen becomes fibrin
What must done after it has been determined that a patient has ACS?
An EKG
What do the 2 results of an EKG determine?
- ST-elevation means STEMI
- ST-depression means HS troponin T test must be done
What do the 2 results of an HS troponin T test mean?
- Elevated troponin T means NSTEMI
- Normal troponin T means unstable angina
