Early repolarization patterns associated with increased arrhythmic risk are common in young non-Caucasian Australian males and not influenced by athletic status

Heart Rhythm. 2015 Jul;12(7):1576-83. doi: 10.1016/j.hrthm.2015.03.060. Epub 2015 Mar 31.


Background: Early repolarization (ER) with a horizontal ST segment (ST-h) and high-amplitude J waves in the inferior leads is associated with an increased risk of cardiac arrhythmic death. The effect of ethnicity and athletic status on this increased-risk ER pattern has not been established. Aboriginal Australian/Torres Strait Islander and Pacific Islander/Maori (non-Caucasian [non-C]) subjects are well represented in Australian sport; however, the patterns and prevalence of ER in these populations are unknown.

Objective: The purpose of this study was to assess the prevalence and effect of athletic activity on ER patterns in young non-C and Caucasian (C) subjects.

Methods: Twelve-lead ECGs of 726 male athletes (23.8% non-C) and 170 male controls (45.9% non-C) aged 16-40 years were analyzed for the presence of ER, defined as J-point elevation (J wave, QRS slur, or discrete ST elevation) ≥0.1 mV in ≥2 inferior (II, III, aVF) or lateral (I, aVL,V4-V6) leads. ST morphology was coded as horizontal (ST-h) or ascending (ST-a). "Increased-risk ER" was defined as inferior ER with ST-h and J waves >2 mV.

Results: Regardless of athletic status, ER and increased-risk ER were more prevalent in non-C than in C subjects (53.8% vs 32% and 7.6% vs 1.2%, respectively, P <.0001). Whereas lower heart rate, larger QRS voltage, and shorter QRS duration were predictors of ER, non-C ethnicity was the only independent predictor of increased-risk ER (odds ratio 17.621, 95% confidence interval 4.98-62.346, P < .0001).

Conclusion: ER patterns associated with increased arrhythmic risk are more common in young non-C than C subjects and were not influenced by athletic status. The long-term clinical significance of ER in these populations is yet to be determined.

Keywords: Athlete; Early repolarization; Ethnicity; Indigenous Australian; Ventricular fibrillation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Athletes / statistics & numerical data*
  • Athletic Performance / physiology
  • Australia / epidemiology
  • Death, Sudden, Cardiac* / etiology
  • Death, Sudden, Cardiac* / prevention & control
  • Electrocardiography / methods
  • Electrophysiologic Techniques, Cardiac
  • Heart Conduction System / physiopathology
  • Humans
  • Male
  • Native Hawaiian or Other Pacific Islander
  • Prevalence
  • Prognosis
  • Risk Assessment
  • Ventricular Fibrillation* / complications
  • Ventricular Fibrillation* / diagnosis
  • Ventricular Fibrillation* / ethnology
  • Ventricular Fibrillation* / physiopathology