Benign early repolarization

Benign early repolarization
ECG of a benign early repolarization in a 15-year-old male
SpecialtyCardiology
Frequency1-13%[1]

Benign early repolarization also known as early repolarization (abbr.: BER) is found on ECG in about 1% of those with chest pain.[2] It is diagnosed based on an elevated J-point / ST elevation where the ST segment is concave up. It is believed to be a normal variant.[2]

Benign early repolarization that occurs in the inferior and lateral portion of the heart muscle is associated with ventricular fibrillation. The association, revealed by research performed in the late 2000s, is small.

Types

Benign early repolarization can be divided into 3 subtypes:[3][4]

  • Type 1 - BER pattern seen in lateral precordial leads. Very prevalent in younger people and healthy male athletes. Low risk of arrhythmic events.
  • Type 2 - BER pattern seen in inferior or inferolateral leads. Moderate risk of arrhythmic events.
  • Type 3 - BER pattern seen globally (inferior, lateral, right precordial leads). Is associated with ventricular fibrillation / ventricular tachycardia storms.

Associations with serious conditions

Research in the late 2000s has linked this finding when found in the inferior and lateral ECG leads to ventricular fibrillation particularly in those who have fainted or have a family history of sudden cardiac death.[5] Studies have shown a significant relationship between ventricular fibrillation and early repolarization.[6][7] Although there is a significant relationship between ventricular fibrillation and early repolarization the overall lifetime occurrence of idiopathic ventricular fibrillation is exceptionally rare.[8] There has also been an association between early repolarization and short QT syndrome.[9]

Risk factors

  • Male gender[10]
  • J-point and horizontal or descending / downsloping ST segment (especially in inferior leads)[10][11][12]
  • Elevation of a J-point by 2 mm[10]
  • Elevation of a J-wave by 0.2 mV or more[13]
  • J-point distribution globally[13]
  • QRS end segment notching[13]
  • Longer duration of J wave, more than 60 ms[14]

Electrocardiography

On an electrocardiogram (EKG or ECG), benign early repolarization may produce an elevation of the J-point and ST segment in 2 or more leads, similar to that observed in heart attacks (myocardial infarction). 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 on the EKG.

Causes

It is thought the causing mechanism of early repolarization is an ion channel system imbalance, which causes varying excitability and refractoriness in myocardium, resulting in voltage gradient between myocardium regions.[13] Studies have shown that higher testosterone levels in males result in an increased outward potassium currents causing J point elevation.[15]

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.[1] 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.[16][17]

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 Africans.[18]

Genetics

Genes associated with ER and ATP sensitive potassium current channel mutations are KCNJ8, ABCC9[11][19][20] Others associated with transient outward potassium current - KCNE5, DPP10, L-type voltage gated calcium current - CACNA1C, CACNB2B, CACNA2D1, sodium current - SCN5A, SCN10A.[14]

History

Early repolarization with ST segment elevation was first described in 1936 by R.A. Shipley and W.R. Hallaran in a study of a 200 healthy 20-35 year old people.[14][21]

References

  1. 1 2 Bourier F, Denis A, Cheniti G, Lam A, Vlachos K, Takigawa M, et al. (2018-11-27). "Early Repolarization Syndrome: Diagnostic and Therapeutic Approach". Frontiers in Cardiovascular Medicine. 5: 169. doi:10.3389/fcvm.2018.00169. PMC 6278243. PMID 30542653.
  2. 1 2 Brady WJ, Chan TC (1999). "Electrocardiographic manifestations: benign early repolarization". The Journal of Emergency Medicine. 17 (3): 473–478. doi:10.1016/S0736-4679(99)00010-4. PMID 10338242.
  3. ↑ Buttner R, Cadogan M (2021-01-21). ""Benign" Early Repolarization Misnomer". Life in the Fast Lane • LITFL. Retrieved 2021-12-25.
  4. ↑ Antzelevitch C, Yan GX, Viskin S (April 2011). "Rationale for the use of the terms J-wave syndromes and early repolarization". Journal of the American College of Cardiology. 57 (15): 1587–1590. doi:10.1016/j.jacc.2010.11.038. PMC 3073061. PMID 21474038.
  5. ↑ Stern S (April 2011). "Clinical aspects of the early repolarization syndrome: a 2011 update". Annals of Noninvasive Electrocardiology. 16 (2): 192–195. doi:10.1111/j.1542-474X.2011.00429.x. PMC 6932469. PMID 21496171.
  6. ↑ Haïssaguerre M, Derval N, Sacher F, Jesel L, Deisenhofer I, de Roy L, et al. (May 2008). "Sudden cardiac arrest associated with early repolarization". The New England Journal of Medicine. 358 (19): 2016–2023. doi:10.1056/NEJMoa071968. PMID 18463377.
  7. ↑ Nam GB, Kim YH, Antzelevitch C (May 2008). "Augmentation of J waves and electrical storms in patients with early repolarization". The New England Journal of Medicine. 358 (19): 2078–2079. doi:10.1056/NEJMc0708182. PMC 2515862. PMID 18463391.
  8. ↑ Priori SG, Wilde AA, Horie M, Cho Y, Behr ER, Berul C, et al. (October 2013). "Executive summary: HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes". Europace. 15 (10): 1389–1406. doi:10.1093/europace/eut272. PMID 23994779.
  9. ↑ Watanabe H, Makiyama T, Koyama T, Kannankeril PJ, Seto S, Okamura K, et al. (May 2010). "High prevalence of early repolarization in short QT syndrome". Heart Rhythm. 7 (5): 647–652. doi:10.1016/j.hrthm.2010.01.012. PMID 20206319.
  10. 1 2 3 Junttila MJ, Sager SJ, Tikkanen JT, Anttonen O, Huikuri HV, Myerburg RJ (November 2012). "Clinical significance of variants of J-points and J-waves: early repolarization patterns and risk". European Heart Journal. 33 (21): 2639–2643. doi:10.1093/eurheartj/ehs110. PMID 22645193.
  11. 1 2 Mercer BN, Begg GA, Page SP, Bennett CP, Tayebjee MH, Mahida S (2016-06-30). "Early Repolarization Syndrome; Mechanistic Theories and Clinical Correlates". Frontiers in Physiology. 7: 266. doi:10.3389/fphys.2016.00266. PMC 4927622. PMID 27445855.
  12. ↑ Sethi, Kamal K.; Sethi, Kabir; Chutani, Surendra K. (2014). "Early repolarisation and J wave syndromes". Indian Heart Journal. 66 (4): 443–452. doi:10.1016/j.ihj.2014.06.002. ISSN 0019-4832. PMC 4150048. PMID 25173204.
  13. 1 2 3 4 Sayedahmad Z, Darmoch F, Al-Khadra Y, Kabach A, Alraies MC (March 2019). "Does early repolarization on ECG increase the risk of cardiac death in healthy people?". Cleveland Clinic Journal of Medicine. 86 (3): 165–166. doi:10.3949/ccjm.86a.17032. PMID 30849033. S2CID 73467268.
  14. 1 2 3 "Early Repolarization Syndrome". American College of Cardiology. Retrieved 2021-12-25.
  15. ↑ Bourier, Felix; Denis, Arnaud; Cheniti, Ghassen; Lam, Anna; Vlachos, Konstantinos; Takigawa, Masateru; Kitamura, Takeshi; Frontera, Antonio; Duchateau, Josselin; Pambrun, Thomas; Klotz, Nicolas (2018). "Early Repolarization Syndrome: Diagnostic and Therapeutic Approach". Frontiers in Cardiovascular Medicine. 5: 169. doi:10.3389/fcvm.2018.00169. ISSN 2297-055X. PMC 6278243. PMID 30542653.
  16. ↑ Serra-Grima R, Doñate M, Álvarez-García J, Barradas-Pires A, Ferrero A, Carballeira L, et al. (February 2015). "Long-term follow-up of early repolarization pattern in elite athletes". The American Journal of Medicine. 128 (2): 192.e1–192.e9. doi:10.1016/j.amjmed.2014.06.017. PMID 24979742.
  17. ↑ Noseworthy PA, Weiner R, Kim J, Keelara V, Wang F, Berkstresser B, et al. (August 2011). "Early repolarization pattern in competitive athletes: clinical correlates and the effects of exercise training". Circulation: Arrhythmia and Electrophysiology. 4 (4): 432–440. doi:10.1161/CIRCEP.111.962852. PMC 3700366. PMID 21543642.
  18. ↑ Sethi KK, Sethi K, Chutani SK (2014). "Early repolarisation and J wave syndromes". Indian Heart Journal. 66 (4): 443–452. doi:10.1016/j.ihj.2014.06.002. PMC 4150048. PMID 25173204.
  19. ↑ Haïssaguerre M, Chatel S, Sacher F, Weerasooriya R, Probst V, Loussouarn G, et al. (January 2009). "Ventricular fibrillation with prominent early repolarization associated with a rare variant of KCNJ8/KATP channel". Journal of Cardiovascular Electrophysiology. 20 (1): 93–98. doi:10.1111/j.1540-8167.2008.01326.x. PMID 19120683. S2CID 21002962.
  20. ↑ Medeiros-Domingo A, Tan BH, Crotti L, Tester DJ, Eckhardt L, Cuoretti A, et al. (October 2010). "Gain-of-function mutation S422L in the KCNJ8-encoded cardiac K(ATP) channel Kir6.1 as a pathogenic substrate for J-wave syndromes". Heart Rhythm. 7 (10): 1466–1471. doi:10.1016/j.hrthm.2010.06.016. PMC 3049900. PMID 20558321.
  21. ↑ Shipley RA, Hallaran W (1936-03-01). "The four-lead electrocardiogram in two hundred normal men and women". American Heart Journal. 11 (3): 325–345. doi:10.1016/S0002-8703(36)90417-9.

Further reading

  • Macfarlane PW, Antzelevitch C, Haissaguerre M, Huikuri HV, Potse M, Rosso R, et al. (July 2015). "The Early Repolarization Pattern: A Consensus Paper". Journal of the American College of Cardiology. 66 (4): 470–477. doi:10.1016/j.jacc.2015.05.033. PMID 26205599.
  • Junttila MJ, Sager SJ, Tikkanen JT, Anttonen O, Huikuri HV, Myerburg RJ (November 2012). "Clinical significance of variants of J-points and J-waves: early repolarization patterns and risk". European Heart Journal. 33 (21): 2639–2643. doi:10.1093/eurheartj/ehs110. PMID 22645193.
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