Acute Coronary Syndrome (ACS)

Question 1

ACS Definition

Answer 1

Acute Coronary Syndrome. Any array of clinical symptoms resulting from underlying acute myocardial ischemia

Almost always associated with rupture of an atherosclerotic plaque and partial or complete thrombosis of the infarct-related coronary artery.

Question 2

What can atherosclerosis cause?

Answer 2

Plaque rupture

Dysfunctional Endothelium

Question 3

Plaque Rupture leads to?

Answer 3

Platelet Activation and coagulation cascade activation which leads to coronary thrombosis

Question 4

Dysfunctional Endothelium leads to?

Answer 4

Decreased vasodilator effect and antithrombotic effect which leads to coronary thrombosis

Question 5

Atherosclerotic Plaque Formation Sequence

Answer 5

1) Endothelial Cells Activated
2) Extracellular lipids form in intima
3) Macrophages become lipid laden foam cells → Lesion grows
4) Fibrous cap weakens and ruptures
5) Coagulation & platelet aggregation
6) THROMBOSIS
7) Partial/Complete Occlusion!

Question 6

Subendocardial Ischemia

Answer 6

ischemia involves the innermost layers of myocardium. Most often due to partial occlusion.

Question 7

Diagnosis of ACS

Answer 7

ECG Evaluation
Serum Biomarkers
Clinical Symptoms

Question 8

ST Change in subendocardial ischemia

Answer 8

ST Depression! ST vector is directed toward inner layer of affected ventricle

Question 9

ST Change in transmural ischemial

Answer 9

ST Elevation! ST vector is directed outward

Question 10

EKG w/ partial occlusion (no infarct)

Answer 10

With chest pain (st depression) and no pain (no st depression)

Question 11

Myocardial Infarction Tests

Answer 11

Troponin I and T- begins to rise at 3-4 hours and peaks at 18-36
Creatine Kinase-MB Isoenzyme- peaks at 24 hours (rises at 3-8 hours) NOT AS SPECIFIC!

Question 12

Angina

Answer 12

Chest pain/ pressure/ tightness

1) Stable
- present w/ increased demand and regular
2) Unstable
- increase in duration
- less provocation at rest
- new onset

Question 13

Unstable Angina vs NSTEMI vs STEMI EKG Findings

Answer 13

ST Depression (may be normal if pain free)
ST Depression
ST Elevation

Question 14

Treatment of ACS- STEMI

Answer 14

OPEN THE ARTERY!
1) Artery can be opened in 90 minutes → Primary Percutaneous Coronary Intervention (PCI)
2) If not, Give fibrinolytic (tPA) and transfer!
Also, reduce O2 demand (B-blockers, nitrates)

Question 15

Treatment of ACS- UA/NSTEMI

Answer 15

1) Halt the propagation of clot (antiplatelet agent and anticoagulant)
2) Reduce myocardial O2 demand

Question 16

Antiplatelet Agent

Answer 16

ASPIRIN
+
Choice of P2Y12 inhibitor: Clopidogrel, Prasugrel or Ticagrelor

If proceeding to catheterization or high risk, consider addition of
Glycoprotein IIa/IIIb inhibitor: Eptifibatide, Tirofiban, (Abciximab)

Question 17

Anticoagulant

Answer 17

Choice of one:
Unfractionated heparin, enoxaparin, fondaparinux

If proceeding to catheterization may consider
Bivalirudin