Left ventricular hypertrophy
I recently performed both of these ECGs a few days apart during the same work week. They were recorded on an outpatient basis. It wasn’t until I recorded the second ECG that I realized I had a good pair of ECGs to illustrate this comparison.
This is a good ECG for demonstrating the voltage and ST criteria for LVH and acute anterior wall M.I. in the same patient, where both conditions have been confirmed by other tests. If you are teaching the topics of ST elevation M.I., or left ventricular hypertrophy, you will probably have to address the issue that LVH can be considered a "mimic" for STEMI, especially for beginners. This is because LVH causes ST depression in leads with upright QRS complexes, and reciprocal ST elevation in leads with negative QRS complexes. This is called ST segment discordance. The ST changes in LVH are due to the "strain" pattern, indicating strain on the left ventricular myocardium. It is true that some ST elevation will appear in V1 and V2 in these patients, and can be mistaken for M.I. In the ECG shown here, the patient has definite ST elevation in leads which would NORMALLY have depression in the LVH strain pattern. Leads V1 through V4 have ST elevation that is not discordant, and is definitely real. This patient was taken to the cath lab, and his left anterior descending artery stented.
This ECG is from an elderly man with long-standing hypertension. It is a good example of LVH, with tall QRS complexes in the left-sided leads (V5, V6) and deep QRSs in right sided chest leads V1 and V2), but a rather unusual axis, in that it is normal, and we often seen left axis deviation with LVH. His hypertrophy is not severe as seen on imaging studies, but he shows an obvious "strain" pattern of sloping ST depression and T wave inversion in leads with upright QRS complexes. The signs of LVH are subtle, but when viewed as a whole ECG, the pattern seems more obvious. Always consider body shape, also, as a very thin person may produce more voltage on the ECG since the electrodes are close to the heart, and a person with a large chest may seem to minimize the QRSs, as we sometimes see with COPD. For more discussion of LVH criteria, go to the "Favorites" page. Every ECG blogger on the blogs list will have a discussion of LVH criteria and significance.