ECG Review: Fatigue for the Last Three Weeks
ECG Review
Fatigue for the Last Three Weeks
By Ken Grauer, MD, Professor, Department of Community Health and Family Medicine, University of Florida. Dr. Grauer is the sole proprietor of KG-EKG Press, and publisher of an ECG pocket brain book.
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Clinical Scenario: The ECG in the tracing above was obtained from a 68-year-old man who presented with a history of fatigue for the past 3 weeks, but no chest pain. No history of coronary artery disease, and no prior tracings were available for comparison. How would you interpret his ECG in view of this clinical history?
Interpretation: The rhythm is sinus tachycardia at a rate of 110/min. The PR and QRS intervals are normal. The QT interval looks to be a bit prolonged, although assessment of the QT is clearly more difficult when there is tachycardia. There is left axis deviation, with a mean QRS axis of about -20°. There is no chamber enlargement. The most interesting part of the tracing relates to assessment of Q-R-S-T changes, which in view of the history strongly suggest that myocardial infarction has occurred at some point during the past 3 weeks. Large Q waves are seen in association with coved ST segment elevation in each of the inferior leads. Although the amount of ST segment elevation is no more than 1 mm, R wave amplitude in these inferior leads is also small, such that these findings could certainly be recent, if not acute. The depth of inferior Q waves, Q wave width in lead III, and the pattern of QRS morphology in lead aVF suggest that inferior infarction occurred at least days (if not a week or more) prior to the recording of this tracing. Small q waves are also seen in leads V3 through V6, with slight but definite coved ST segment elevation and shallow T wave inversion seen in V6. This suggests lateral wall involvement. Deep ST segment depression is seen in leads V1 through V4. In addition, transition appears to be early, with R wave amplitude exceeding S wave depth between leads V1 and V2. Although the ST segment depression in this tracing could represent reciprocal changes occurring in association with the patient's recent infero-lateral infarction, it might also represent posterior wall involvement. In patients with a left dominant circulation, the circumflex coronary artery supplies the inferior, posterior, and lateral walls of the left ventricle. Acute occlusion of this artery might produce the electrocardiographic picture seen here. With acute posterior involvement, the anterior leads (leads V1 through V3) provide a mirror-image view of what is occurring electrocardiographically in the posterior wall. As a result, one typically sees either early transition or a tall R wave in lead V1 in association with the type of anterior ST segment depression seen here. Thus, the reason for this patient's 3 week history of fatigue is his recent infero-lateral-posterior infarction that may still be ongoing.
The ECG in the tracing above was obtained from a 68-year-old man who presented with a history of fatigue for the past 3 weeks, but no chest pain. No history of coronary artery disease, and no prior tracings were available for comparison. How would you interpret his ECG in view of this clinical history?Subscribe Now for Access
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