1. ECG interpretation for beginners Part 4 – Acute coronary syndromes
Paul Williams
Cardiology Specialist Registrar

2. Normal ECG!

3. Not only ED – can happen on ward!

4. MI diagnosis Use your system Don’t forget rate, rhythm etc.
Need to have basic understanding of:
Pathology of heart attacks
Coronary arteries and regions of heart

8. Coronary arteries 2 coronary arteries come off aorta
Total of 3 main coronary arteries
LCA
LMS branches into:
Left anterior descending (LAD)
Circumflex (Cx)
RCA

10. Left ventricle supply
LAD – Supplies anterior wall, septum +- lateral walls(60%)
Cx – Supplies lateral wall (15%)
RCA – Supplies inferior and posterior walls (25%). Also supplies RV & conducting tisse

11. Septal
Lateral
Anterior
Lateral
Inferior

12. Other territories Inferior MI – can have RV involvement
RV leads - V4R
Posterior MI – Usually ST depression V1- V3

13. The hallmark of acute ischaemia is ST segment shift
ST elevation = complete blockage = STEMI
ST depression = partial blockage = NSTEMI/USA
Generally only occurs when patient has symptoms: ACS are dynamic
If real, usually have changes in contiguous leads

15. STEMI
Occluded coronary artery
Emergency = myocardium is dying!

16. STEMI Changes evolve: Dynamic - repeat ECGs if not sure
Often “hyperacute” T waves initially
T wave inversion
Q waves
Dynamic - repeat ECGs if not sure
What territory is it?
Two contiguous leads
Can get reciprocal ST depression
Remember posterior & RV involvement

17. Differential Pericarditis Widespread concave upsloping ST depression
Would involve multiple coronary arteries if MI
PR depression (II)
Look at the patient – common sense

18. Management of STEMI ABC Cardiac monitor (can go into VF) Analgesia
Aspirin
Clopidogrel
Reperfusion therapy
Thrombolysis
Primary PCI
Medical Rx

19. Septal
Lateral
Anterior
Lateral
Inferior

23. Old MIs Old STEMIs can leave permanent Q waves
Territories are the same (anterior, inferior lateral etc.)
Poor R wave progression can also indicate an old anterior STEMI

25. ST depression

26. ST depression Often get T wave inversion as well
Remember your territories
Generally ST depression only occurs during acute ischaemia
Differential
Digoxin (downsloping lateral: V4-V6, I, aVL)
LVH (downsloping lateral)

28. Management of NSTEMI/USA
ABC
Cardiac monitor
Analgesia
Initial medical Rx
Aspirin
Clopidogrel
Beta-blocker
Statin
LMWH
IP angiography

29. Question 1
What are the ECG abnormalities?
What is the differential?

30. Question 2 What are the ECG abnormalities? What sort of ACS?
What territory is affected?

31. Question 3 What are the ECG abnormalities What sort of ACS?
What territory?

32. Question 4 What are the ECG abnormalities?
Give 3 possible differentials

33. Question 5 What are the ECG abnormalities? What sort of ACS?
What territory?