Benign Early Repolarisation

AKA: “J-point elevation”, “high take-off”

Clinical Relevance

  • Benign early repolarisation (BER) is a ECG pattern most commonly seen in young, healthy patients < 50 years of age.
  • It produces widespread ST segment elevation that may mimic pericarditis or acute MI.
  • Up to 10-15% of ED patients presenting with chest pain will have BER on their ECG, making it a common diagnostic challenge for clinicians.
  • The 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.
  • BER is less common in the over 50s, in whom ST elevation is more likely to represent myocardial ischaemia.
  • It is rare in the over 70s.

Avoid diagnosing BER in patients over the age of 50, especially those with risk factors for ischaemic heart disease.

How to recognise BER

  • Widespread concave ST elevation, most prominent in the mid- to left precordial leads (V2-5).
  • Notching or slurring at the J-point.
  • Prominent, slightly asymmetrical T-waves that are concordant with the QRS complexes (pointing in the same direction).
  • The degree of ST elevation is modest in comparison to the T-wave amplitude (less than 25% of the T wave height in V6)
  • ST elevation is usually < 2mm in the precordial leads and < 0.5mm in the limb leads, although precordial STE may be up to 5mm in some instances.
  • No reciprocal ST depression to suggest STEMI (except in aVR).
  • ST changes are relatively stable over time (no progression on serial ECG tracings).

Example

  • There is generalised concave ST elevation in the precordial (V2-6) and limb leads (I, II, III, aVF).
  • J-point notching is evident in the inferior leads (II, III and aVF).
  • There are prominent, slightly asymmetrical T waves that are concordant with the main vector of the QRS complexes.

ST segment / T wave morphology

The ST segment-T wave complex in BER has a characteristic appearance:

  • There is elevation of the J point
  • The T wave is peaked and 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

The concavity of the ST segment has been described as having the appearance of a “smiley face”.

Typical morphology of BER

Image adapted from Edhouse, Brady & Morris (2002).

Click image for link to original source

J-point morphology

One characteristic feature of BER is the presence of a notched or irregular J point: the so-called “fish hook” pattern. This is often best seen in lead V4.

Examples of J-point notching:

Image adapted from Edhouse, Brady & Morris (2002).

Temporal Stability of BER

Although the ST elevation of BER does not show rapid progression like STEMI, nor evolution over several weeks like pericarditis, the ECG pattern is 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.
  • The ST elevation may gradually disappear over time as the 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 a 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.

Example 1 (heart rate = 54 bpm)

  • The ST elevation and J-point notching are more prominent at a slower heart rate.

 

Example 2 (heart rate = 76 bpm)

  • The ST elevation and J-point notching become less prominent as the heart rate increases.

Check out this post from Dr Smith’s ECG blog for another example of this interesting phenomenon. 

 

Benign Early Repolarisation vs Pericarditis

BER can be difficult to differentiate from pericarditis as both conditions are associated with concave ST elevation.

One useful trick to distinguish between these two entities is to look at the 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.
  • A ratio of > 0.25 suggests pericarditis
  • A ratio of < 0.25 suggests BER

 

Example 1: Benign Early Repolarisation

  • ST segment height = 1 mm
  • T wave height = 6 mm
  • ST / T wave ratio = 0.16
  • The ST / T wave ratio < 0.25 is consistent with BER.

 

Example 2: Pericarditis

  • ST segment height = 2 mm
  • T wave height = 4 mm
  • ST / T wave ratio = 0.5
  • The ST / T wave ratio > 0.25 is consistent with pericarditis.

The main differences between pericarditis and BER are summarised below.

 

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 relatively stable over time

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 over time

NB. These features have limited specificity, therefore it may not always be possible to tell the difference between these two conditions.

 

Look at this ECG example:

Is this BER or pericarditis?

  • There is widespread concave ST elevation suggesting pericarditis.
  • However, the ST elevation is markedly more prominent in the precordial leads (esp. V2-5), consistent with BER.
  • There appears to be some subtle downsloping PR depression in the limb (I, aVL) and precordial leads (V3-6), with subtle PR elevation in aVR, suggesting pericarditis.
  • The J wave notching (fish-hook pattern) in V3-V4 is highly suggestive of BER.
  • There are prominent T waves in the precordial leads, suggestive of BER.
  • The ST / T wave ratio of 0.16 is also consistent with a diagnosis of BER.
  • These ECG appearances could be caused by BER alone, although it is possible that this ECG represents BER with superimposed pericarditis. This ECG demonstrates the difficulty in differentiating between these two very similar conditions.
  • Remember that it is possible for a patient with BER to get pericarditis! 

Benign Early Repolarisation plus Pericarditis

The following two ECGs demonstrate what happens when a patient with BER develops pericarditis. The baseline ECG was taken from a fit 23-year old male military recruit during a routine health evaluation. The subsequent ECG was taken from the same patient several months later when he presented with pleuritic chest pain and was found to have pericarditis.

Baseline ECG: Benign Early Repolarisation

  • Widespread minor ST elevation and J-point notching consistent with BER

 

Follow-up ECG: Benign Early Repolarisation + Pericarditis!

  • Relatively tachycardic heart rate (95 bpm) for a fit young man.
  • Widespread concave ST elevation, noticeably increased compared to previous ECG.
  • New widespread PR depression with PR elevation in aVR.

 

More Examples of BER

 

  • This example was originally featured on the EMS-1.com website.

 

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 found an increased prevalence of early repolarization among patients with a history of idiopathic ventricular fibrillation.

Blog Posts on BER

  • LITFL’s Peter Allely gives a nice summary of BER here.
  • Mel Herbert and Stuart Swadron discuss benign early repolarisation on EMRAPTV here.
  • EMS 12-Lead‘s Tom Bouthillet explains BER with some great ECG examples here.
  • Dr Stephen Smith discusses some clever ways to distinguish between BER and acute ischaemia here.

Related Topics

Further Reading

Author Credits

References and Links

Journal articles and textbooks

  • Chan TC, Brady WJ, Harrigan RA, Ornato JP and Rosen PR. ECG in Emergency Medicine and Acute Care. Elsevier 2005
  • Edhouse J, Brady WJ, Morris F. ABC of clinical electrocardiography: Acute myocardial infarction-Part II. BMJ. 2002; 324: 963-6. [full text].
  • Haïssaguerre M, Derval N, Sacher F, Jesel L, Deisenhofer I, de Roy L, et al. Sudden cardiac arrest associated with early repolarization. N Engl J Med. 2008 May 8;358(19):2016-23 [full text].
  • Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.
  • Surawicz B, Knilans T. Chou’s Electrocardiography in Clinical Practice (6th edition), Saunders 2008.
  • Tikkanen JT, Anttonen O, Junttila MJ, Aro AL, Kerola T, Rissanen HA, et al. Long-term outcome associated with early repolarization on electrocardiography. N Engl J Med. 2009 Dec 24;361(26):2529-37 [full text].

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