1. 2 Great resources ECG Pedia http://en.ecgpedia.org/wiki/Main_Page
Great tutorials
Very good explanations
ECG Wave Maven
Made by Harvard Docs to prove they are Harvard Docs
All 12-lead interpretation
Hard but very informative

5. This is a normal 12 –lead EKG

6. This is a STEMI 12-lead
Notice the ST segment elevations in leads II, III, and aVF.

7. This is a NSTEMI 12-lead
Notice the ST depression and T wave changes in leads II, III, and aVF.

8. With Inferior MI think Right sided MI
Notice the ST segment elevations in leads II, III, and aVF.

9. Walk V4 to the right

10. V4R

11. Terminology AMI = Acute Myocardial Infarction
Read: Heart attack happening right now
STEMI = ST Segment Elevated Myocardial Infarction
Read: heart attack that we can see on a 12 lead happening right now
NSTEMI = Non-ST Segment Elevated Myocardial Infarction
Read: heart attack that we suspect but cannot see ST segment elevation, possibly happening right now

12. Terminology Ischemia = a decrease in blood supply to an area of cells
Necrosis = dying tissue
What happens with prolonged ischemia
Infarct = an area of cells that became necrotic from ischemia

13. Changes in the leads tell us…
What section of the left ventricle is ischemic or necrotic
Read: where in the heart attack is occurring
Suspected arteries that could be occluded
Tells the cardiologist where to look first
If the right side of the heart is involved in the AMI
Alters treatment (no nitro, no morphine, YES fluids)
Possibly how extensive the damage is or can be
Major artery gets occluded it is usually called a ”Widow Maker”

14. 12 lead interpretation The ST segment
Elevation = myocardial injury
Dead cardiac tissue conducts no impulse
Depression in reciprocal leads is common
Section dies = others take over work & are stressed
Measurement
J point
Where the ST segment takes off from the QRS
Infarction stages
Normal
Ischemic
Injury
Necrosis

15. 12 lead Interpretation The T Wave
T wave morphology
Peaking
Tall & narrow
Inversion
Normal in aVR and V1
Symmetry
Symmetrical inversion is ischemia

16. 12 lead interpretation the Q Wave
Pathological Q waves
> 0.04s duration (> 1mm)
Read: wider than 1 small box)
1/3 depth of R wave
Read: Deeper than the R wave
Q waves
New & old
Normal vs Pathological
R Wave
Q Wave

17. A NSTEMI is an AMI or heart attack without ST segment elevation.
NSTEMIs are trickier to diagnose as the changes in the 12-lead can be subtle and easy to miss.