Benign early repolarization (BER) or early repolarization is found on an electrocardiogram (ECG) in about 1% of those with

chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with n ...

. It is diagnosed based on an elevated

J-point The QRS complex is the combination of three of the graphical deflections seen on a typical electrocardiogram (ECG or EKG). It is usually the central and most visually obvious part of the tracing. It corresponds to the depolarization of the ri ...

/ ST elevation with an end-QRS notch or end-QRS slur and where the ST segment concave up. It is believed to be a normal variant. Benign early repolarization that occurs as some patterns is associated with

ventricular fibrillation Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the Ventricle (heart), ventricles of the heart Fibrillation, quiver. It is due to disorganized electrical conduction system of the heart, electrical activity. Ventricula ...

. The association, revealed by research performed in the late 2000s, is very small.

Types

Benign early repolarization, very prevalent in younger people and healthy male athletes, can be divided into 3 subtypes: * Type 1 – BER pattern seen in lateral precordial leads. * Type 2 – BER pattern seen in inferior or inferolateral leads. * Type 3 – BER pattern seen globally (inferior, lateral, right precordial leads).

Associations with serious conditions

Research in the late 2000s has linked this finding to

, particularly in those who have fainted or have a family history of

sudden cardiac death Cardiac arrest (also known as sudden cardiac arrest ''SCA is when the heart suddenly and unexpectedly stops beating. When the heart stops beating, blood cannot properly circulate around the body and the blood flow to the brain and other org ...

. Although there is a significant relationship between

and some early repolarization's patterns, the overall lifetime occurrence of idiopathic ventricular fibrillation is exceptionally rare. There has also been an association between early repolarization and

short QT syndrome Short QT syndrome (SQT) is a very rare genetics, genetic disease of the electrical system of the heart, and is associated with an increased risk of Heart arrhythmia, abnormal heart rhythms and sudden cardiac death. The syndrome gets its name from ...

Risk factors

* Male gender * J-point and horizontal or descending / downsloping ST segment (especially in inferior leads) * Elevation of ST segment by 2 mm * Elevation of a J-wave by 0.2 mV or more * J-point distribution globally * QRS longer than 110 ms *Longer duration of J wave, more than 60 ms

Electrocardiography

On an electrocardiogram (EKG or ECG), benign early repolarization may produce an elevation of the

and

ST segment In electrocardiography, the ST segment connects the QRS complex and the T wave and has a duration of 0.005 to 0.150 sec (5 to 150 ms). It starts at the J point (junction between the QRS complex and ST segment) and ends at the beginning of the T ...

in 2 or more leads, similar to that observed in heart attacks (

myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...

). However, with benign early repolarization, the ST segment is usually concave up, rather than concave down (as with heart attacks), and there is a notable absence of reciprocal changes suggestive of

ischemia Ischemia or ischaemia is a restriction in blood supply to any tissue, muscle group, or organ of the body, causing a shortage of oxygen that is needed for cellular metabolism (to keep tissue alive). Ischemia is generally caused by problems ...

on the EKG.

Causes

It is thought that the mechanism causing early repolarization is a more excitable

ion channel Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by Gating (electrophysiol ...

system, which causes a faster myocardium contraction. Studies have shown that higher

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

levels in males result in an increased outward potassium currents causing J-point elevation.

Epidemiology

Benign early repolarization occurs in about 1 to 13 percent of the general population with a significant increase in occurrence within athletes and adolescents. In one study, an occurrence of early repolarization was observed in 31.6% of elite athletes while in another study occurrence was observed in 25.1% of athletes. Being a male is strongly associated with early repolarization ECG pattern, and 70% of subjects with early repolarization are males. Prevalence of early repolarization declines in males from early adulthood until middle-age which could suggest a hormonal influence on its presence. Early repolarization patterns are more common in physically active younger individuals, athletes and

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

ns.

Genetics

Genes associated with ER and ATP sensitive potassium current channel mutations are

KCNJ8 Potassium inwardly-rectifying channel, subfamily J, member 8, also known as KCNJ8, is a human gene encoding the Kir6.1 protein. A mutation in KCNJ8 has been associated with cardiac arrest in the early repolarization syndrome. Potassium channels ...

ABCC9 ATP-binding cassette, sub-family C member 9 (ABCC9) also known as sulfonylurea receptor 2 (SUR2) is an ATP-binding cassette transporter that in humans is encoded by the ''ABCC9'' gene. Function The protein encoded by this gene is a member of ...

Others associated with transient outward potassium current ''-'' KCNE5, DPP10, L-type voltage gated calcium current ''-'' CACNA1C, CACNB2B,

CACNA2D1 Voltage-dependent calcium channel subunit alpha-2/delta-1 is a protein that in humans is encoded by the ''CACNA2D1'' gene. This gene encodes a member of the alpha-2/delta subunit family, a protein in the voltage-dependent calcium channel complex ...

, sodium current -

SCN5A Sodium channel protein type 5 subunit alpha, also known as NaV1.5 is an integral membrane protein and tetrodotoxin-resistant voltage-gated sodium channel subunit. NaV1.5 is found primarily in cardiac muscle, where it mediates the fast influx of ...

SCN10A Nav1.8 is a sodium ion channel subtype that in humans is encoded by the ''SCN10A'' gene. Nav1.8-containing channels are tetrodotoxin (TTX)-resistant voltage-gated channels. Nav1.8 is expressed specifically in the dorsal root ganglion (DRG), in ...

History

Early repolarization with ST segment elevation was first described in 1936 by R.A. Shipley and W.R. Hallaran in a study of 200 healthy 20–35 year old people.

References

External links

Benign Early Repolarisation on litfl.com

Early Repolarization – ECGpedia
Electrodiagnosis Cardiac arrhythmia fr:Repolarisation précoce