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

This is a normal 12 –lead EKG

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

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

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

Walk V4 to the right

V4R

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

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

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”

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

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

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

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.