ECG Review: DKA and Acute MI?
ECG Review: DKA and Acute MI?
By Ken Grauer, MD
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Figure. 12-lead ECG obtained from a 32-year-old man who presented in DKA.
Clinical Scenario: The ECG in the Figure was obtained from a previously healthy 32-year-old African American male who presented in coma from diabetic ketoacidosis (DKA). Cardiovascular exam was unremarkable. In addition to treating this patient’s DKA, should he also be considered a potential candidate for thrombolytic therapy?
Interpretation: The ECG in the Figure shows normal sinus rhythm at a rate of about 60/minute. The PR interval is at the upper range of normal (= 0.21 second). The QRS and QT intervals are normal. The mean QRS axis is +60°. In view of the patient’s age, there is no evidence of chamber enlargement. Perhaps the most remarkable finding on this tracing is the presence of diffuse ST segment elevation. This finding is present in virtually all leads except III, aVR, and V1. It is most marked in lead V5, where ST segment elevation attains at least 3 mm.
Despite the presence of diffuse ST elevation, it is highly unlikely that this pattern represents acute infarction. ST segment morphology is clearly upsloping (upward concavity), with marked notching of the J point in multiple leads (especially II, V4, V5, V6). The ST segment appearance that is characteristic of acute infarction is more typically coved (downward convexity) and is usually localized to 1 or 2 specific lead areas, rather than being as generalized as it is here. Marked acute ST segment elevation indicative of acute infarction is also commonly associated with reciprocal ST segment depression, which is not seen here. Although Q waves are present in the inferolateral leads, they are quite small and narrow. This is much more consistent with normal septal q waves rather than acute evolving infarction. Clearly, clinical correlation is needed. However, given the young age of this patient, his negative past medical history, the apparent absence of chest pain, and the ECG picture described above, early repolarization is almost certain to be the cause of diffuse ST elevation in this case.
The shape of ST segment elevation provides a key clue to its etiology in this case (upsloping in multiple leads with prominent J-point notching). Admittedly, acute pericarditis can at times produce diffuse ST elevation similar to that seen here. However, the history in this case does not suggest acute pericarditis, tachycardia is absent, no mention of a pericardial friction rub is made, and the ECG picture with prominent J-point notching seen here is much more suggestive of early repolarization.
Dr. Grauer, Professor, Assistant Director, Family Practice Residency Program, University of Florida, ACLS Affiliate Faculty for Florida, is Associate Editor of Internal Medicine Alert.
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