Ecg interpretation; summary

EMI ECG Interpretation Format or Recipe

Remember, if you follow a systematic approach, your success rate will be enhanced!

Step 1. 

Assess the lateral leads (I, aVL, V5, and V6).

Begin with Lead I. Look for normal or abnormal Q waves. Is the ST segment on the baseline? If not, is it depressed/inverted (e.g. ischemia) or elevated (e.g. injury).

Is there an R wave in every lead (except aVR, which we are ignoring)?

Continue to look at all of the Lateral Leads as if they were a family grouping. Examine leads I. aVL, V5 and V6 again. Do you find changes in at least two of the four leads? Continue to examine the Q, R, and ST segments.

Write down your “summary of the lateral wall”... You are now read to progress and evaluate the inferior wall.

Step 2. 

Assess the inferior leads (II, III, aVF).

Look for normal or abnormal Q waves.

Is there an R wave in all three leads? (There should be although the amplitude in lead III and aVF may be small).

Is the ST segment on the baseline? If not, is it depressed/inverted (e.g. ischemia) or elevated (e.g. injury).

Look at the inferior leads as a family. You must find changes in at least two out of three leads. 

Step 3. 

Examine the anterior leads (V1-V4).

Are there any abnormal Q waves?

Do you see upright R waves in all leads? Do the R waves grow or become progressively larger in amplitude? (they should).

Are the ST segments on the baseline in all leads except V1 which is biphasic? Evaluate the anterior leads as a family. Are there changes or abnormalities in at least two of the four leads?

Good Job!! Now you are ready to prioritize and summarize!

Step 4. 

Identify acute injury (if present).

This is the most dangerous and requires immediate attention.

Remember acute injury is characterized by ST segment elevation which must be seen in the majority of the “lead groupings” (e.g. ST elevation seen in two thirds of the inferior leads II, III, and aVF).

Step 5. 

Identify patterns of ischemia (if present).

Remember ischemia is recorded as ST or T wave inversion. This typically reflects an inadequate oxygen supply to meet the myocardial demands.

This is an opportunity to intervene and prevent a transmural or STEMI.

Step 6. 

Identify any “old” acute MI patterns

Old MIs are permanently recorded on the ECG as abnormal Q waves with normal ST

segments and T waves. The wide and deep Q waves will never go away.

Remember that loss of R wave voltage may also be seen in these same leads.