ECGs to interpret

Question 1

What are the STEMI criteria?

Answer 1

STEMI criteria

ST elevation in >2 small squares in 2 adjacent chest leads [v1-v6]

ST elevation >1 small square in 2 adjacent limb leads

[three bipolar limb leads (I, II, and III), the unipolar limb leads (AVR, AVL, and AVF)]

OR

New LBBB

Question 2

What does this ECG show?

Answer 2

Posterior (wall of LV) infarction

Dominant R wave in V1/2 (like right ventricular hypertrophy but without other changes)

ST depression

NB: Q waves can only be seen by placing limb leads on pts back

Question 3

How can you tell previous infarcts?

Answer 3

Previous infarcts

T-wave inversion (last weeks-months) and pathological Q waves (permanent)

Question 4

What does this ECG show?

Answer 4

Left ventricular hypertrophy

R-wave >5 big squares in V5/6,

T wave inversion in lateral leads (I, aVL, V5-6)

Question 5

What does this ECG show?

Answer 5

Right ventricular hypertrophy

Dominant R wave in V1

T wave inversion in right chest leads (V1-3)

Right axis deviation

Question 6

What does this ECG show?

Answer 6

Hypertrophic cardiomyopathy

Left ventricular hypertrophy signs

[R-wave >5 big squares in V5/6,

T wave inversion in lateral leads (I, aVL, V5-6)]

Dramatic T wave inversion in lateral leads (maximal in V4 rather than in V6)