Benign Early Repolarisation (BER) a.k.a High Take Off
An ECG pattern showing widespread ST elevation. It is most common in young (below 50yrs) and healthy patients.
In the pre-hospital setting, diagnose this extremely carefully, and have full knowledge of the variety of morphologies of the ST segment in high take off before assuming.
Benign early repolarization mimics pericarditis and STEMI.
Morphologies of BER
ST Segment and T wave Morphology in BER
There is a typical appearance in the ST segment-T wave complex in BER:
The J point is elevated
The T wave is peaked and sometimes slightly asymmetrical
The ST segment and the ascending limb of the T wave form an upward concavity
The descending limb of the T wave is straighter and slightly steeper than the ascending limb
A GOOD WAY TO REMEMBER USING FACES:
SMILEY IS UPWARD
CONCAVITY AND FROWNY IS DOWNARD CONCAVITY
ECG Characteristics of BER
Widespread concave ST elevation, most prominent in the precordial leads (V2-5)
Notching or slurring at the J point
Prominent, sometimes asymmetrical T waves that are concordant with the QRS complex
ST elevation : T wave height ratio in V6 < 0.25
No reciprocal ST depression to suggest Occlusion MI
ST/T Wave Ratio
ST segment height = 1 mm
T wave height = 6 mm
ST/T wave ratio = 0.16
The ST/T wave ratio <0.25 so is consistent with BER
J Point Morphology in BER
Another common characteristic of BER is the presence of a notched or irregular J point. It is called the ‘fish-hook’ pattern and seen best in V4.
This can also be seen in V5 and V6 but notice how the morphology of the notched J point changes throughout the leads and is most obvious in V4.
Benign Early Repolarization vs Pericarditis
Pre-hospital clinicians face large challenges differentiating between BER and pericarditis, this is because both conditions are associated with concave ST elevation.
Looking at the ST segment / T wave ratio in V6 and the fish hook pattern will aid distinguishing between the two.
ST Segment / T wave ratio:
The vertical height of the ST segment elevation (from the end of the PR segment to the J point) is measured and compared to the amplitude of the T wave in V6:
ST / T wave ratio of > 0.25 suggests pericarditis
ST / T wave ratio of < 0.25 suggests BER
Example of Pericarditis
ST segment height = 2 mm
T wave height = 4 mm
ST / T wave ratio = 0.5
The ST / T wave ratio > 0.25 so is consistent with pericarditis
