History Is Everything
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.
Scenario: Interpret the ECG above, obtained from a patient presenting to the Emergency Department. Is there any cause for concern?
Interpretation: The ECG shows sinus rhythm at 85/minute. The PR interval is normal. The QRS duration is upper normal (half a large box, but not more) and the QT interval is upper normal (about half the R-R interval, with a QTc ≈ 0.44 second). The axis is normal (+70°). There is right atrial abnormality (tall, peaked P wave in lead II ≥ 2.5 mm); possible left atrial abnormality (minimally deep negative component to the P in lead V1); and left ventricular hypertrophy (S in V1,2 + R in V5,6 ≥ 35 mm). Regarding Q-R-S-T changes, there is at most a tiny q in lead III, and transition is normal (between V2 to V4). The most remarkable finding on this tracing are the ST segments, which manifest at least 2 mm of J point elevation with straight (if not coved) takeoff in leads V2,V3. There is slight elevation with J point notching in lead V4. Missing from this presentation is the history and mention of prior tracings for comparison. At the very least we suspect multichamber enlargement and a probable cardiomyopathy. If the patient had new-onset chest pain, acute coronary syndrome with ST elevation would have to be ruled out. If ECG findings were chronic, ST-T changes from medication effect, early repolarization, cardiomyopathy, or some combination of these would have to be considered. History is everything in the interpretation of this tracing.