75 yo M with h/o bladder ca presents with 6 hrs of left sided substernal non radiating chest pain that woke him from sleep. Pain is constant and he reports it to be severe. EKG obtained from triage as follows:
compared to old from 1 yr ago,
Pt has st depressions in v2-v5, and in inferior leads (II, III, aVF). Also concerning is the tall R wave suggestive of posterior MI.
DDX of Prominent R wave in Lead V1
1.right bundle branch block
2. right ventricular hypertrophy
3. Wolff-Parkinson-White syndrome
4. posterior MI
5. Lead placement error
6. normal variant.
Posterior MI can be isolated or can occur with inferior or lateral MI (R coronary or L circumflex A, respectively)
Suspect posterior MI when EKG shows:
1. ST depression > 1 mm in V1-V3
2. Tall R in V1 or V2
3. Tall, upright T wave in V1 or V2
Posterior placed leads (V7-V9): wraps towards left scapula and are the mirror image of the septal leads (V1-V3)
Quick Trick while waiting for repeat EKG: Flip and invert EKG and look at V1-V3 for ST elevation / T wave inversion
A posterior EKG was obtained:
This EKG does not show ST elevations in the posterior leads. An acute ST elevation MI was not the cause of his chest pain. This case will be revisited in future posts.
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