ECG Blog #60 — LVH/Acute MI vs Normal Variant?

The ECG in Figure 1 was on my desk for interpretation.

• How would you interpret this ECG?
• Does this ECG Reflect ACS (Acute Coronary Syndrome) and/or Acute STEMI (ST Elevation Myocardial Infarction)?
• What clinical information is lacking?
• Is there LVH (Left Ventricular Hypertrophy) – at least by voltage?

Figure 1 – Does this ECG suggest acute ischemia and/or infarction?

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INTERPRETATION: Our Descriptive Analysis of this tracing begins as follows: Sinus arrhythmia (as determined by slight but definite variation in the R-R interval); normal intervals; marked left axis (approximately -40 degrees – which is consistent with LAHB = Left Anterior HemiBlock).

• At this point - further interpretation requires some information about the patient (namely age of the patient and whether or not the patient is healthy and asymptomatic vs an older adult with new-onset chest pain).
• HALF STANDARDIZATION: It is easy to overlook that this 12-lead ECG was obtained at HALF standardization. Note that the standardization rectangle (seen at the very beginning of the tracing) is only 5mm (=1 large box) tall. Actual amplitude is therefore double that seen in Figure 1 (ie, the S wave in lead V2 is really 24mm in depth – not the 12mm that we count on this tracing).
• Regarding Q-R-S-T Changes: No Q waves are seen. Transition occurs early (ie, between V1-to-V2). That said - the most remarkable finding on this tracing relates to the ST-T waves, which show ST segment coving with symmetric T wave inversion in many leads. There is at least slight ST elevation in leads V2,V3,V4.

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Importance of Clinical History:

This is an interesting ECG, in that its interpretation will be very different, depending on the clinical setting. In actual fact – this ECG was obtained as part of a “pre-participation physical” performed on an otherwise healthy 20-year-old football player. Past medical history was negative – and physical exam was normal (no heart murmur).

• ST segment coving with slight elevation and T wave inversion (as present in Figure 1) – may occasionally be seen in healthy young adults as a less common type of normal repolarization variant. Given this patient’s age and absence of symptoms – that almost certainly is the explanation here.
• Nevertheless – this is an unusual tracing for a healthy young adult. The surprisingly tall R wave already by lead V2 suggests prominent septal forces. We would therefore advise obtaining an Echocardiogram prior to clearing this individual for active sports participation to rule out anatomic abnormality (such as hypertrophic cardiomyopathy).

An entirely different interpretation would be in order IF the ECG in Figure 1 was instead obtained from an older adult with chest pain. In this case:

• The ST segment coving with slight elevation and symmetric T wave inversion in multiple leads might clearly reflect acute ischemia/infarction. This would need to be ruled out.
• Voltage for LVH would be present (deepest S in V1,V2 + tallest R in V5,V6 definitely exceeds 35mm given half standardization).

FINAL THOUGHT: It may be helpful to make a wallet-sized copy of this ECG for this individual to carry as record of their baseline ECG. Having this copy could prove invaluable for comparison purposes if this individual ever developed chest discomfort.

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- For more information - GO TO:

• See Section 09.0 (from ECG-2014-ePub) for more on Repolarization Variants. The part on Early Repolarization begins in Section 09.14. - 

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