Physiological basis of BER is poorly understood.
However, it is generally thought to be a normal variant that is not indicative of underlying cardiac disease.
Temporal Stability of BER
Although ST elevation of BER
- Not show Rapid progression like STEMI,
- Nor evolution over several weeks like pericarditis
- Not Entirely Static Over time:
The degree of ST elevation may fluctuate in response to changes in Autonomic tone:-
• Diminishing with increased sympathetic tone /
Exercise / Tachycardia or
• Increasing when the heart rate slows. or may
• Disappear gradually over time as patient ages:
up to 30% of patient with BER will have resolution
of ST elevation on ECGs taken many years later.
Variation with Heart Rate
~~~~~~~~~~~~~~~~~~~~~~
The following two ECGs were taken 24 hours apart from a healthy 17-year old female (admitted to hospital following benzodiazepine overdose). She had no chest pain and cardiac biomarkers were normal. You can see how the ECG features of BER vary with the heart rate.
Benign Early Repolarisation vs Pericarditis
Pericarditis can be difficult to differentiate from Benign Early Repolarisation (BER) as both conditions are associated with concave ST elevation.
One Trick to distinguish these two entities is to look at :-
-
ST segment / T wave ratio and
-
Fish Hook Pattern
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 amplitude of T wave in V6.
A ratio of > 0.25 suggests pericarditis
A ratio of < 0.25 suggests BER
Features suggesting BER
- ST elevation limited to the precordial leads
- Absence of PR depression
- Prominent T waves
- ST segment / T wave ratio < 0.25
- Characteristic “fish-hook” appearance in V4
- ECG changes usually stable over time
(i.e non-progressive)
Features suggesting pericarditis
-
Generalised ST elevation
-
Presence of PR depression
-
Normal T wave amplitude
-
ST segment / T wave ratio > 0.25
-
Absence of “fish hook” appearance in V4
-
ECG changes evolve slowly over time
NB. These features have limited specificity,
therefore it may not always be possible to tell the difference between these two conditions.
Not So Benign?
In the past couple of years the benign nature of this ECG pattern has been called into doubt:
A large Finnish cohort study published in NEJM Dec 2009 found that an early-repolarization pattern in the inferior leads was associated with an increased risk of death from cardiac causes in middle-aged subjects over a 30-year follow-up period.
Another study examined sudden cardiac arrest associated with early repolarization and found an increased prevalence of early repolarization among with a history of idiopathic ventricular fibrillation.