How do you recognize a Posterior STEMI?

-FIRST, you need to suspect it!
-Only 10 % occur as isolated Posterior STEMI, most occur WITH inferior or lateral STEMI

What do you look for on an EKG?

-Remember that the EKG leads look at the anterior heart so the mirror image must be true for a Posterior STEMI in leads V1-v3

-Instead of ST elevations, you see ST Depressions
-Instead of Q waves, you see tall R waves
-Instead of flipped T waves, you see upright T waves

Example

How can you look at the posterior leads on an EKG?

–Place 3 leads (V7,V8,V9) below the right scapula (see picture) and look for ST elevations, Q waves and T wave inversions!

What coronary vessel is often implicated?

Posterior Descending Artery of the Right Coronary Artery (right dominant circulation)

How do you recognize a right ventricular infarction on an EKG?

-Often see ST elevations in V1, and in Lead III>Lead II
–ST elevations in the right sided leads (especially V4R)-see picture below
–Get that Right sided EKG if you suspect RV infarct!

Why is it important to recognize?

-Up to 40% of inferior STEMI can be associated with a RV infarction
-These patients are PRELOAD sensitive, so their blood pressures will tank if you give them nitrates or other preload reducers-they need FLUID RESUSCITATION

References

LITFL (Life in the Fast Lane)- an excellent resource for ECGs amongst others