Early repolarization patterns associated with increased arrhythmic risk are common in young non-Caucasian Australian males and not influenced by athletic status
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) subjects are well represented in Australian sport, however the patterns and prevalence of ER in these populations are unknown.
The aim of our study was to assess the prevalence and the effect of athletic activity on ER patterns in young non-Caucasian and Caucasian (C) subjects.
The ECGs of 726 male athletes (23.8% non-C) and 170 male controls (45.9% non-C) aged 16-40 were analyzed for the presence of ER, defined as J-point elevation (J-wave, QRS-slur or discrete ST-elevation) of ≥0.1mV in ≥2 inferior (II,III,aVF) or lateral (I,aVL,V4-V6) leads. ST-morphology was coded as horizontal or ascending. ‘Increased-risk ER’ was defined as inferior ER with ST-h and J-waves >2mV.
Regardless of athletic status, ER and increased-risk ER were more prevalent in non-C than C (53.8% vs 32% and 7.6% vs 1.2%, respectively, p<0.0001). Whilst lower heart rate, larger QRS voltages and shorter QRS-duration were predictors of ER, non-C ethnicity was the only independent predictor of increased-risk ER (OR 17.621,95% CI 4.98-62.346,p <0.0001).
ER patterns associated with increased arrhythmic risk are more common in young non-C than C subjects and not influenced by athletic status. The long-term clinical significance of ER in these populations is yet to be determined.
Abbreviations:A (athletic), AMI (acute myocardial infarction), BSA (body surface area), C (Caucasian), CV (cardiovascular), ECG (12-lead electrocardiogram), ER (early repolarization), IPVF (idiopathic ventricular fibrillation), LVH (left ventricular hypertrophy), NA (non-athletic), Non-C (subjects of Aborginal Australian/Torres Strait Islander and Pacific Islander/Maori heritage), QTc (corrected QT interval), SCD (sudden cardiac death), ST-a (ascending ST-segment), ST-h (horizontal ST-segment)
Autor / Fonte:Maria J Brosnan, Saurabh Kumar, Andre La Gerche, Alex Brown, Simon Stewart, Jonathan M Kalman, David L Prior Heart Rhythm: the Official Journal of the Heart Rhythm Society 2015 March 31