How Many Leads Are Abnormal?
March 15, 2022 2 minutes read
By Ken Grauer, MD
Professor Emeritus in Family Medicine, College of Medicine, University of Florida
The figure below was obtained after cardiac catheterization for new chest pain. The rhythm is sinus bradycardia at ~50 beats/minute. All intervals are normal. The axis is leftward, but not enough to qualify as a hemiblock. There is no chamber enlargement.
A Q wave and/or a Q wave “equivalent” is present in each inferior lead. There is poor R wave progression, with loss of R wave between lead V2 and V3. Although small, considering the small R wave amplitude in leads V5 and V6, the Q waves in these leads likely are significant. Of most concern are the “hyperacute” T waves that are seen in the inferior leads and in all six chest leads.
Virtually each hypervoluminous ST-T wave is associated with at least slight (if not more) J-point ST elevation. Both high lateral leads (I and aVL) manifest ST-T wave depression, with the ST-T wave in lead aVL presenting a mirror-image opposite picture of the elevated ST-T wave in lead III. Details about the history in this case are lacking, beyond learning this patient presented with new chest pain that led to cardiac catheterization. Considering this clinical situation, the fairly marked sinus bradycardia is clinically relevant. Virtually all leads on this ECG (except for aVR) are markedly abnormal. The combination Q waves and Q wave “equivalents,” with loss of R wave amplitude between lead V2 and V3 (in association with diffuse hyperacute T wave changes), is diagnostic of recent (if not ongoing) extensive myocardial infarction.
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The figure was obtained after cardiac catheterization for new chest pain. The rhythm is sinus bradycardia at ~50 beats/minute. All intervals are normal. The axis is leftward, but not enough to qualify as a hemiblock. There is no chamber enlargement.
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