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

Normal ECG!

Not only ED – can happen on ward!

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

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

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

Septal Lateral Anterior Lateral Inferior

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

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

STEMI Occluded coronary artery Emergency = myocardium is dying!

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

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

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

Septal Lateral Anterior Lateral Inferior

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

ST depression

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)

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

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

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

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

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

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