Acute Coronary Syndrome

Question 1

What is Acute Coronary Syndromes (ACS)?

Answer 1

ACS

• Any array of clinical symptoms resulting from underlying acute myocardial ischemia
  
  • i.e. - mismatch of demand vs supply
• Most often caused by ruptuture of atherosclerotic plaque and partial/complete thrombosis
  
  • i.e. - includes unstable angina , NSTEMI & STEMI – (not stable angina)

Question 2

ACS Epidemiology

1. How many Americans per year suffer from ACS?
2. What precentage of people will die from ACS?

Answer 2

ACS Epidemiology

1. 1.7 million people per year (note the decimal point)
2. Approx 38% will die from ACS

Question 3

What is the main cause of ACS?

Answer 3

Atheroscleoritc plaque rupture with thrombus

Question 4

1. What is transmural ischemia?
2. What is subendocardial ischemia?

Answer 4

1. Transmural: ischemia spans the entire thickness of the myocardium
   
   • Most often due to occlusion
2. Subendocardial: ischemia involves the innermost layers of the myocardium only
   
   • Most often due to partial occlusion

If ischemia is prolonged results in myocyte death and tissue necrosis - i.e. M.I.

Question 5

Transmural infarcts

1. What is the clinical name for it?
2. What are the ECG findings c/w it?
3. What would the serum biomarkers look like?

Answer 5

Tranmural Infarcts

1. Otherwise known as STEMI
2. ST-segment elevation
3. Positive Troponin-I/T & CK-MB

Question 6

Subendocardial Infarcts

1. Clinical name?
2. ECG findings?
3. Serum markers?

Answer 6

Subendocardial infarcts

1. Otherwise known as NSTEMI
2. ST-segment depression and/or T-wave inversion
3. Positive Troponin-I/T & CK-MB

Question 7

Troponins vs Creatine Kinase-MB

1. Which is more sensitive/specific for myocardium?
2. When do Troponins/CK-MB rise?
3. When do Troponins/CK-MB peak?

Answer 7

1. Troponin
2. Troponin rise after 3-4 hr after onset of pain/ischemia
   
   • CK-MB begin to rise 3-8hr after
3. Troponin peak at 18-36 hrs
   
   • CK-MB peaks at 24 hrs

Question 8

Describe the physiology behind elevated troponin levels in the blood during/after an M.I.

Answer 8

Troponin

• Regulatory protein in muscle cells that controls interactions between myosin and actin
  
  • Disruption of sarcolemma -> leak of intracellular molecules into cardiac interstitium -> blood

Question 9

What are the clinical symptoms of stable vs unstable angina?

Answer 9

Stable Angina

• Present when there is increased demand for myocardial O2 in a reproducible fashion

Unstable Angina

• Increase in duration, intensity, or frequency
• Less provocation/can occur at rest
• New onset

Question 10

Unstable Angina

1. Amount of vessel occlusion?
2. Serum biomarkers?
3. ECG findings?

Answer 10

Unstable Angina

1. Partial vessel occlusion
2. Negative Troponin/CK-MB
3. ST-depression

Question 11

Treatment of ACS–STEMI

What is the treatment algorhythm?

Answer 11

Algorhythm:

• Access to a cath lab w/in 90 min?
  
  • Yes
    
    • Cath lab -> Primary PCI (i.e. angioplasty/stent)
  • No
    
    • Fibrinolytic therapy (e.g. tPA)
• Add beta blockers/nitrates as adjuvant therapy

Question 12

Treatment of ACS–UA/NSTEMI

What is the treatment algorhythm for unstable angina and NSTEMI?

Answer 12

• Halt the progression of the clot using both
  
  • Anti-platelet agent
    
    • Aspirin + P2Y12 inhibitor (Clopidogrel)
  • Anticoagulant
    
    • Unfractionated heparin or enoxaparin
• Reduce myocardial oxygen demand
  
  • Beta blockers & nitrates
• Catheterization for percutaneous coronary intervention (PCI) – at some point