Take a close look at the EKG above. I picked it because it demonstrates an important finding. Look at V1 and V2…….notice anything abnormal? Do you see the R waves in V1 and V2? This is an abnormal finding. Compare that with this normal EKG below:
Notice in this normal EKG the R waves in V1 and V2 have less amplitude than the S wave in the same leads. This means they are normal. In the first EKG, the R waves were taller than the S waves, which is an abnormal finding.
The goal of this blog entry is to give you a good differential for a tall R wave in V2 (and V2.) I think there are 5 important emergent diagnoses to consider when you see this on EKG:
- Posterior MI
- Acute right heart strain
Other diagnoses include: dextrocardia, misplaced precordial leads, hypertrophic cardiomyopathy and normal variant.
So what about the initial EKG above? This EKG shows an OLD posterior wall MI. Think of the R waves as Q-waves since lead V1 is on the anterior chest wall instead of the posterior chest wall. If it were an acute posterior MI, you would see ST segment depression in these leads.