Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On February 26-27, 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

244Word Count: 4664 ABSTRACT Aim: To describe the electrocardiographic (ECG) and echocardiographic manifestations of the paediatric athlete's heart, and examine the impact of age, race and sex upon cardiac remodelling responses to competitive sport. Design: Systematic review and meta-analysisData sources: Six electronic databases were searched to May 2016: MEDLINE, PubMed, EMBASE, Web of Science, CINAHL and SPORTDiscus.Inclusion criteria: 1) Male and/or female competitive athletes, 2) participants aged 6-18 years, 3) original research article published in English language.Results: Data from 14,278 athletes and 1,668 non-athletes were included for qualitative (43 articles) and quantitative synthesis (40 articles). Paediatric athletes demonstrated a greater prevalence of training-related and training-unrelated ECG changes than non-athletes. Athletes ≥14 years were 15.8 times more likely to have inferolateral T-wave inversion than athletes <14 years. Paediatric black athletes had significantly more training-related and training-unrelated ECG changes than Caucasian athletes. Age was a positive predictor of left ventricular (LV) internal diameter during diastole, interventricular septum thickness during diastole, relative wall thickness and LV mass. When age was accounted for, these parameters remained significantly larger in athletes than non-athletes. Paediatric black athletes presented larger posterior wall thickness during diastole (PWTd) than Caucasian athletes. Paediatric male athletes also presented with larger PWTd than females. Conclusions:The paediatric athlete's heart undergoes significant remodelling both before and during 'maturational years'. Paediatric athletes have a greater prevalence of training related and training-unrelated ECG changes than non-athletes, with age, race and sex mediating factors on cardiac electrical and LV structural remodelling. Word count: 244 What is already known? Chronic training loads are associated with a number of electrophysiological, structural and functional cardiac adaptations in adult athletes.  Race and sex significantly impact upon the cardiac remodelling of the adult athlete's heart.  Paediatric athletes undergo significant growth and maturational changes; but unlike known musculoskeletal changes, there is limited information regarding how the heart may adapt to training before, during and after puberty. What are the new findings? Paediatric athletes were up to 13 times more likely to have deep T-wave inversion (TWI) (≥2mm) than age-matched non-athletes  Paediatric athletes ≥14 years of age were up to 16 times more likely to have inferolateral TWI (warranting further investigation) than athletes <14 years  Paediatric black athletes were up to 36 times more likely to have extended anterior TWI (leads V1-V4) than Caucasians.  Even after accounting for age, left ventricular structural parameters were larger among paediatric athletes than paediatric non-athletes

BackgroundAn increasing number of sporting bodies report unacceptably high levels of false-positive ECGs when undertaking pre-participation cardiac screening. To address this issue, modified ECG interpretation criteria have become available for use within athletes.ObjectiveThis study assessed the accuracy of the new 2014 ‘Refined Criteria’ against the 2013 Seattle Criteria and the 2010 European Society of Cardiology (ESC) recommendations in a cohort of Arabic, black and Caucasian athletes.Methods2491 male athletes (1367 Arabic, 748 black and 376 Caucasian) undertook pre-participation screening including a 12-lead ECG, with further investigation(s) upon indication.ResultsTen athletes (0.4%) were identified with cardiac pathology; seven with hypertrophic cardiomyopathy (HCM; five black and two Arabic) and three Arabs with Wolff–Parkinson–White syndrome (WPW). All three ECG criteria were 100% sensitive identifying all cases of HCM and WPW. The 2014 Refined Criteria reduced (p<0.0001) the prevalence of an abnormal ECG to 5.3% vs 11.6% (Seattle Criteria) and 22.3% (2010 ESC recommendations). The 2014 Refined Criteria significantly (p<0.0001) improved specificity (94.0%) across all ethnicities compared with the Seattle Criteria (87.5%) and ESC recommendations (76.6%). Black athletes continue to present a higher prevalence (p<0.0001) of abnormal ECGs compared with Arabic and Caucasian athletes (10% vs 3.6% and 2.1%).ConclusionsThe 2014 Refined Criteria for athlete ECG interpretation outperformed both the 2013 Seattle Criteria and the 2010 ESC recommendations by significantly reducing the number of false-positive ECGs in Arabic, black and Caucasian athletes while maintaining 100% sensitivity for serious cardiac pathologies.

PurposeTo determine associations between thermal responses, medical events, performance, heat acclimation and health status during a World Athletics Championships in hot-humid conditions.MethodsFrom 305 marathon and race-walk starters, 83 completed a preparticipation questionnaire on health and acclimation. Core (Tcore; ingestible pill) and skin (Tskin; thermal camera) temperatures were measured in-competition in 56 and 107 athletes, respectively. 70 in-race medical events were analysed retrospectively. Performance (% personal best) and did not finish (DNF) were extracted from official results.ResultsPeak Tcore during competition reached 39.6°C±0.6°C (maximum 41.1°C). Tskin decreased from 32.2°C±1.3°C to 31.0°C±1.4°C during the races (p<0.001). Tcore was not related to DNF (25% of starters) or medical events (p≥0.150), whereas Tskin, Tskin rate of decrease and Tcore-to-Tskin gradient were (p≤0.029). A third of the athletes reported symptoms in the 10 days preceding the event, mainly insomnia, diarrhoea and stomach pain, with diarrhoea (9% of athletes) increasing the risk of in-race medical events (71% vs 17%, p<0.001). Athletes (63%) who performed 5–30 days heat acclimation before the competition: ranked better (18±13 vs 28±13, p=0.009), displayed a lower peak Tcore (39.4°C±0.4°C vs 39.8°C±0.7°C, p=0.044) and larger in-race decrease in Tskin (−1.4°C±1.0°C vs −0.9°C±1.2°C, p=0.060), than non-acclimated athletes. Although not significant, they also showed lower DNF (19% vs 30%, p=0.273) and medical events (19% vs 32%, p=0.179).ConclusionTskin, Tskin rate of decrease and Tcore-to-Tskin gradient were important indicators of heat tolerance. While heat-acclimated athletes ranked better, recent diarrhoea represented a significant risk factor for DNF and in-race medical events.

The collective term 'black' should not imply that the hearts of all black athletes are universally comparable. There is considerable variability in the cardiac electrical and structural remodelling response to exercise that appears to be dependent on geographic origin.

Background: International electrocardiographic (ECG) recommendations regard anterior Twave-inversion (ATWI) in athletes <16 years to be normal. Design: Identify the prevalence, distribution, and determinants of TWI by ethnicity, chronological and biological age within paediatric athletes. Secondly, establish diagnostic accuracy of international ECG recommendations against refinement within athletes who present ECG variants isolated to ATWI (V1-V4) using receiver operator curve (ROC) analysis. Clinical context was calculated using Bayesian analysis. Methods: 418 Arab and 314 black male athletes (11-18 years) were evaluated by ECG, echocardiogram and biological age (via radiological x-ray) assessment. Results: 116 (15.8%) athletes presented ATWI (V1-V4), of which 96 (82.8%) were ECG variants isolated to ATWI. 91 (12.4%) athletes presented ATWI confined to V1-V3, with prevalence predicted by black ethnicity (odds ratio (OR) 2.2; 95% CI 1.3-3.5) and biological age <16 years (OR 2.0; 95% CI 1.2-3.3). Of the 96 with ATWI (V1-V4) observed in the absence of other ECG findings considered to be abnormal as per international recommendations for ECG interpretation in athletes, diagnostic accuracy was 'fail' (0.47 95% CI 0.00-1.00) for international recommendations and 'excellent' (0.97 95% CI 0.92-1.00), when governed by biological age <16 years, providing a positive (+LR) and negative (-LR) likelihood ratio of 15.8 (95% CI 1.8-28.1) and 0.0 (95% CI 0.0-0.8), respectively. Conclusion: Interpretation of ECG variants isolated to ATWI (V1-V4) using international recommendations (chronological age <16 years), warrants caution, but governance by biological age yielded an 'excellent' diagnostic accuracy. In clinical context, the 'chance' of detecting cardiac pathology within a paediatric male athlete presenting ATWI in the absence of other ECG findings considered to be abnormal as per international recommendations for ECG interpretation in athletes (+LR=15.8), was 14.4%, whereas a negative ECG (-LR=0.0) was 0%.