Module 7: Cardiac causes of cardiac arrest

Question 1

ACS are the clinical syndromes caused by a disease process of:

Answer 1

• Atherosclerotic plaque rupture
• SM contraction
• Thrombus formation

—> UA, NSTEMI, or STEMI

Question 2

Stable angina

Question 3

Unstable angina

Answer 3

1. Angina on exertion with increasing frequency over a few days, provoked by less exertion “crescendo angina” OR
2. Angina recurrently/unpredictably not specific to exercise OR
3. Unprovoked and prolonged CP

*ECG may be normal
*ST-depression suggests high-risk
*No troponin (as no damage to heart muscle)

Question 4

Can you use ECG alone to differentiate UA from NSTEMI?

Answer 4

No – the ECGs could be the same
Troponin is needed to differentiate (indicates myocyte death)

Question 5

NSTEMI

Answer 5

• Symptoms suggesting acute MI
• Troponin release*** GUARANTEED
• Non-specific ECG changes
  -> ST depression
  -> TWI
  -> May be normal

Question 6

STEMI

Answer 6

• Symptoms suggesting acute MI
• Troponin release*** GUARANTEED
• Acute ST elevation
• Q waves likely to develop
• Erly effective Tx incl reperfusion therapy may limit myocardial damage & prevent Q wave development

Question 7

Why is it so important to differentiate NSTEMI from STEMI?

Answer 7

Acute treatment is different

Question 8

Immediate treatment for all ACS patients?

Answer 8

1. ABCDE approach
2. Loading dose aspirin (300mg crush/chew) - protects against new thrombus formation
3. Sublingul nitrate (GTN spray or tablet)
4. Morphine
5. Oxygen if hypoxic

Question 9

+Managemnet for UA or NSTEMI?

Answer 9

1. Antithrombotic – prevent further thrombus formation that might fully block the artery
   
   • aspirin
   • prasugrel/ticagrelor/clopidogrel (platelet inhib)
2. Pain relief
   
   • nitrate
   • morphine
3. Oxygen if hypoxic
4. Myocardial protection
   
   • Beta-blocker
   • Coronary angio/PPCI in most patients - generally not done as emergency unless high-risk

Question 10

+management for STEMI

Answer 10

1. Emergency coronary reperfusion
   
   • Primary PCI (optimal treatment)
   • Fibrinolytic if no access to PPCI
   • Avoid delay -> “time is muscle”

Question 11

Stemi further management

Answer 11

• Anti-thrombotic therapy
• Bet-blocker
• ACEi
• Coronary angio/PPCI if hd initial fibrinolytic therapy

Question 12

Absolute CIs to fibrinolytic therapy

Answer 12

• Bleeding disorder
• Recent major surgery or trauma
• Previous hemorrhagic stroke
• Other stroke or CVA <6mo
• CNS damage or neoplasm
• Active internal bleeding
• Aortic dissection