Electrocardiogram Interpretation In Athletes Research Articles

Electrocardiographic findings and cardiovascular risk profile in paralympic athletes

Abstract Funding Acknowledgements Type of funding sources: None. Background Paralympic athletes are a special group of elite athletes with unique cardiovascular issues. Recently, the term "Paralympic medicine" has been used to describe the specific medical conditions of athletes participating in the Paralympics. However, there are limited data regarding cardiovascular screening in Paralympic athletes. Purpose To assess the prevalence of normal and abnormal cardiac findings and cardiovascular risk factors in a subset of male Paralympic athletes. Methods From April 2019 to July 2021, male Paralympic athletes who were selected for participation in Paralympic Games in non-endurance sports disciplines, underwent cardiac screening including history, physical examination, 12-leads electrocardiogram (ECG), echocardiography and blood test. Athletes were classified according to the sports disciplines into three groups: 1) skill (archery, shooting, taekwondo, judo); 2) power (weightlifting, discus throwing, shot putting, javelin throwing) and 3) mixed (sitting volleyball, wheelchair basketball, rowing). As well as divided base on the type of disability into two groups: 1) athletes with spinal cord injury (SCI), and 2) athletes with non-spinal cord injuries (NSCI). All ECG were interpreted according to international recommendations for ECG interpretation in athletes. Results Among 82 Paralympic athletes (mean age, 33.7 [21-49] years), there were 19 (23%) in skill, 25 (31%) in power, and 38 (46%) in mixed sports disciplines and 24 (30%) had SCI and 58 (70%) had NSCI. There were no abnormalities observed in two-dimensional echocardiography. Normal ECG findings were seen in 28 athletes (34.1%) with a higher prevalence in athletes with NSCI (41.3%) and participated in mixed (47.3%) sports discipline (p<0.001). Borderline ECG findings were detected in 6 (7.3%) with more frequent in athletes with SCI (12.5%) and participated in power (16%) sports disciplines (p<0.001). The prevalence of abnormal ECG findings were 3.6% and there was no significant difference regard to type of disability and sports disciplines. Cardiac risk factors including hypertension was detected in 8 (9.7%); triglycerides >200 mg/dl in 21 (25.6%), total cholesterol >200 mg/dl in 15 (18.2%), 25-hydroxyvitamin D3 <30 ng/ml in 35 (42.6%), low-density lipoprotein cholesterol >130 mg/dl in 8 (9.7%), very low-density lipoprotein cholesterol ≥50 mg/dl in 15 (18.2%) and high-density lipoprotein cholesterol <40 mg/dl in 7 (8.5%); that were significantly more frequent in athletes with SCI and athletes participated in power sports disciplines (p<0.001). Conclusions The overall prevalence of borderline ECG findings and cardiovascular risk factors are unexpectedly high in Paralympic athletes. This study emphasizes that Paralympic athletes especially those with SCI and participating in power sports disciplines are not immune from cardiovascular risk factors and requires more medical care attention through relevant cardiovascular screening strategies.

Prevalence and diagnostic significance of de-novo 12-lead electrocardiogram patterns following covid-19 infection in elite soccer players

Abstract Funding Acknowledgements Type of funding sources: None. Background Considering that myocarditis is implicated in 5-15% of all exercise related sudden cardiac deaths in athletes, following a novel viral pandemic, the identification and risk-stratification of affected athletes remains an important priority. Given its widespread availability, the inclusion of a 12-lead electrocardiogram (ECG) is common to all consensus-based protocols from North America and Europe. However, a single cross-sectional ECG is problematic because several physiological repolarisation changes are also common manifestations in individuals with myopericarditis. Purpose The aim of our study was to report on the prevalence and diagnostic significance of de-novo ECG patterns following COVID-19 infection in a well-defined cohort of elite soccer players in the English, Dutch and Brazilian leagues. Methods In this multicentre observational study, between March 2020–May 2022, we evaluated consecutive athletes with COVID-19 infection. ECGs were reported in accordance with the International recommendations for ECG interpretation in athletes. The following patterns were also considered abnormal if they were not detected on the pre-COVID-19 infection ECG: PR-segment depression, new J-point and ST segment elevation, low QRS voltages, QRS fragmentation, new ST-segment depression, new T-wave inversion, biphasic T-waves and a reduction in the T-wave amplitude by 50% or T-wave flattening. Athletes exhibiting de-novo ECG changes underwent cardiovascular magnetic resonance (CMR) scans. One club mandated CMR scans for all players (n=30) following COVID-19 infection, despite the absence of cardiac symptoms or de-novo ECG changes. Results 511 soccer players (median age 21-years, IQR:18-26-years) were included, of which 88% were male and 58% white. 17 (3%) athletes demonstrated de-novo ECG changes, which included, a reduction in T-wave amplitude in the inferior and lateral leads (n=5), inferior leads (n=4) and lateral leads (n=4); inferior T-wave inversion (n=7), and ST-segment depression (n=2). 15 (88%) athletes with de-novo ECG changes revealed CMR evidence of inflammatory cardiac sequalae. All athletes who underwent a mandatory CMR irrespective of illness severity or ECG findings, had normal findings. Athletes revealing de-novo ECG changes, had a higher prevalence of cardiac symptoms (71% v 12%; p<0.0001) and longer median symptom duration (5-days, IQR:3-10) compared with athletes without de-novo ECG changes (2-days, IQR:1-3; p<0.001). Among athletes without cardiac symptoms, the additional yield of de-novo ECG changes to detect cardiac inflammation was 17%. Conclusions 3% of athletes demonstrated de-novo ECG changes post COVID-19 infection, of which 88% were diagnosed with inflammatory cardiac sequalae. Most affected athletes exhibited cardiac symptoms; however de-novo ECG changes contributed to a diagnosis of cardiac inflammation in 17% of athletes without cardiac symptoms.

The International Criteria for Electrocardiogram Interpretation in Athletes: Common Pitfalls and Future Directions.

Preparticipation cardiovascular screening (PPCS) in young athletes is performed to detect conditions associated with sudden cardiac death. Many medical societies and sports governing bodies support the addition of a 12-lead electrocardiogram (ECG) to the history and physical to improve PPCS sensitivity. The current standard for ECG interpretation in athletes, the International Criteria, was developed to distinguish physiologic from pathologic ECG findings in athletes. Although application of the International Criteria has reduced the PPCS false-positive rate, interpretative challenges and potential areas of improvement remain. This review provides an overview of common pitfalls and future directions for ECG interpretation in athletes.

Paediatric and adolescent athletes in Switzerland: age-adapted proposals for pre-participation cardiovascular evaluation.

High-level sports competition is popular among Swiss youth. Even though preparticipation evaluation for competitive athletes is widespread, screening strategies for diseases responsible for sudden death during sport are highly variable. Hence, we sought to develop age-specific preparticipation cardiovascular evaluation (PPCE) proposals for Swiss paediatric and adolescent athletes (under 18 years of age). We recommend that all athletes practising in a squad with a training load of at least 6 hours per week should undergo PPCE based on medical history and physical examination from the age of 12 years on. Prior to 12 years, individual judgement of athletic performance is required. We suggest the inclusion of a standard 12-lead electrocardiogram (ECG) evaluation for all post-pubertal athletes (or older than 15 years) with analysis in accordance with the International Criteria for ECG Interpretation in Athletes. Echocardiography should not be a first-line screening tool but rather serve for the investigation of abnormalities detected by the above strategies. We recommend regular follow-up examinations, even for those having normal history, physical examination and ECG findings. Athletes with an abnormal history (including family history), physical examination and/or ECG should be further investigated and pathological findings discussed with a paediatric cardiologist. Importantly, the recommendations provided in this document are not intended for use among patients with congenital heart disease who require individualised care according to current guidelines.

CHARACTERISTICS OF RESTING ECG AMONG SABAH PROFESSIONAL MALE FOOTBALLERS

The purpose of this study is to describe the resting electrocardiogram (ECG) seen among 176 professional male footballers from Sabah Football Association Club during preparticipation evaluation. Data were analysed retrospectively from 2017 to 2019. Majority of the players were Sabah natives (n=153, 87%) while the remaining were Malay footballers (n=23, 13%). Mean age of the players was 19.9 ± 3.1, mean body mass index was 22.6 kg/m2 ± 7, mean resting heart rate was 53.6 beats per minute ± 9.4, mean systolic blood pressure was 122.3 mmHg ± 12, and mean diastolic blood pressure was 65.1 mmHg ± 8.8. Using the International Criteria for ECG Interpretation in Athletes 2017 consensus guidelines, 8.5% (n=15) had abnormal ECG while 2.8% (n=5) had borderline ECG. The most common ECG changes seen in the normal findings were sinus bradycardia (n=123, 69.9%), early repolarization (n=115, 65.3%) and left ventricular hypertrophy (n=83,47.2%). Abnormal ECGs were abnormal t wave inversion (n=7,4.0%) and pre-excitation syndrome (n=5,2.9%). All footballers with abnormal ECG findings were subjected to further evaluation by a cardiologist using echocardiography assessment and exercise stress test. They passed the cardiology assessment; thus, they were deemed fit to play. ECG is a valuable tool for pre-participation health screening prior to exercise or sports participation, as it is vital for a physician to identify any abnormal ECG to minimise the risk of sudden cardiac death during exercise due to cardiac pathology.

Characteristics of resting ECG among sabah professional male footballers

The purpose of this study is to describe the resting electrocardiogram (ECG) seen among 176 professional male footballers from Sabah Football Association Club during preparticipation evaluation. Data were analysed retrospectively from 2017 to 2019. Majority of the players were Sabah natives (n = 153, 87%) while the remaining were Malay footballers (n = 23, 13%). Mean age of the players was 19.9 ± 3.1, mean body mass index was 22.6 kg/m2 ± 7, mean resting heart rate was 53.6 beats per minute ± 9.4, mean systolic blood pressure was 122.3 mmHg ± 12, and mean diastolic blood pressure was 65.1 mmHg ± 8.8. Using the International Criteria for ECG Interpretation in Athletes 2017 consensus guidelines, 8.5% (n = 15) had abnormal ECG while 2.8% (n = 5) had borderline ECG. The most common ECG changes seen in the normal findings were sinus bradycardia (n = 123, 69.9%), early repolarization (n = 115, 65.3%) and left ventricular hypertrophy (n = 83,47.2%). Abnormal ECGs were abnormal t wave inversion (n = 7,4.0%) and pre-excitation syndrome (n = 5,2.9%). All footballers with abnormal ECG findings were subjected to further evaluation by a cardiologist using echocardiography assessment and exercise stress test. They passed the cardiology assessment; thus, they were deemed fit to play. ECG is a valuable tool for pre-participation health screening prior to exercise or sports participation, as it is vital for a physician to identify any abnormal ECG to minimise the risk of sudden cardiac death during exercise due to cardiac pathology.

Evaluating the 12-Lead Electrocardiogram for Diagnosing ARVC in Young Populations: Implications for Preparticipation Screening of Athletes

BackgroundArrhythmogenic right-ventricular cardiomyopathy (ARVC) is an identified cause of sport-related sudden cardiac arrest (SCA). Identifying athletes with ARVC and restricting them from exercise is believed to reduce the risk of SCA. The electrocardiogram (ECG) is considered to be an important component of screening for ARVC; however, the sensitivity of the 12-lead ECG to identify ARVC in young asymptomatic persons is unknown. MethodsIn this retrospective study, we identified 70 patients (49 ARVC-positive, based on Task Force Criteria, and 21 age-matched ARVC-negative persons from a paediatric arrhythmia database (<18 years of age); ECGs were analyzed for abnormalities, based on International Criteria for Interpretation of ECGs in Athletes, and ECG findings were adjudicated by group consensus. ResultsOf the 49 ARVC-positive patients (median age: 17 [interquartile range: 16-18], 65% male), 22% were found to have abnormal ECGs; the most common ECG findings were T-wave inversions. Patients with symptoms were more likely to have abnormal ECGs than asymptomatic patients (28% compared with 17%, respectively; P = 0.002). Of 16 gene-positive patients, 31% had abnormal ECGs. Patients with abnormal ECGs had larger right-ventricular end-diastolic volume indexes on magnetic resonance imaging than those with normal ECGs (P = 0.03). ConclusionsThe ECG was insensitive for detecting ARVC in young (age <18 years), asymptomatic patients, and is unlikely to provide significant diagnostic value for identifying ARVC on routine preparticipation screening of adolescent athletes.

Physiological or pathological hypertrophy of athlete’s heart syndrome

Intense physical activity increases the risk of sudden death by 10–17 fold. Some of the most important tasks of modern pathophysiology in sports medicine include searching for factors that allow an athlete’s body to adapt to loads, understanding the line between adaptation and pathology and identifying risk groups of adaptation failure. It is necessary to distinguish between hypertrophic cardiomyopathy and true myocardial hypertrophy in athletes that results from the adaptation of the cardiovascular system to intense physical exertion. In Seattle, the American Medical Society of Sports Medicine together with the European Society of Cardiology proposed standards for the interpretation of electrocardiogram in athletes and considered criteria for the detection of pathological changes. The best functional state of an athlete and the effectiveness of his/her training are noted with high autonomy and high variability of heart rate. This is reflected in rhythmocardiogram data by increases in high frequency and root mean square of successive differences in heartbeats and a decrease in the low-frequency to high-frequency ratio.A promising direction in the study of markers of an athletic heart is the analysis of echocardiographic (EchoCG) images of young and professional athletes. According to EchoСG analysis, nonadaptive remodelling is the loss of the ellipsoid shape of the left ventricle in favour of a spherical one. In athletes, when assessing transmitral flow by EchoCG, a low A peak can be considered a reserve of adaptive capabilities of the heart and not a pathology. For athletes-dischargers, a concentric variant of changing the geometry of the myocardium is characteristic. Upon reaching the qualification of a candidate, master of sportsan eccentric change in the left ventricle cavity prevails.Funding: The study did not have sponsorship.Conflict of interest: Authors declare no conflict of interest.Author contributionsConception and design: Y.P. Skirdenko Drafting the article: A.V. Gorbenko, O.V. Zamahina, S.A. SherstyukCritical revision of the article: N.A. NikolaevFinal approval of the version to be published: A.V. Gorbenko, Y.P. Skirdenko, N.A. Nikolaev, O.V. Zamahina, S.A. Sherstyuk, A.V. Ershov

Identifying Electrocardiogram Pattern Changes and Their Association with Echocardiography among Malaysian Footballers Attending PreParticipation Evaluation

Introduction: Sudden cardiac death is the most common medical cause of death in athletes. The aim of this study was to identify the electrocardiogram (ECG) pattern changes and its association with echocardiography among Malaysian footballers during a pre-participation evaluation (PPE). Methods: A retrospective study was conducted on footballers attending a PPE at a primary care centre. Secondary data collection was conducted and the proforma included clinical history, physical examination, ECG, Echocardiogram and cardiovascular riskfactors assessment such as heart rate, blood pressure, lipid profile, fasting blood sugar and creatinine. Data were extracted from the medical records, echocardiogram report and the original ECG. The ECG patterns were analysed according to the International consensus for ECG interpretation in athletes to determine physiological versus pathological changes. The data was analysed using SPSS v24. Results: This study included 85 male Malaysian footballers with a mean age of 20.1 ± 3.0 years. The mean resting heart rate was 55.2 ± 9.3beats per minute. Abnormal ECG changes were found in 20% of the participants, which were higher compared to that reported in other studies (14% – 17.3%). The normal ECG findings in athletes were sinus bradycardia (76.5%), J-point elevation (68.2%), prolonged PR interval (3.5%) and incomplete right bundle branch block (4.7%). The abnormal ECG changes were multiple T wave inversions (5.9%), hypertrophy (2.4%), and deep Q-waves (8.2%). Four abnormal ECGs were consistent with abnormal echocardiography findings and out of these,two ECGs with hypertrophic changes were consistent with mild inter atrial septal bulging and apical hypertrophy. Conclusions: Malaysian footballers have ECG changes that are consistent with physiological changes in athlete’s heart. The positive association between ECG and Echocardiogram findings are useful in confirming pathological ECG changes. Physicians should be trained in PPE protocol and ECG interpretation in athletes in order to improve identification of those at risk of sudden cardiac death.

Electrocardiographic changes among elite athletes in Port Harcourt, Nigeria

Background: Due to cardiac adaptations in athletes, the normal electrocardiogram (ECG) may be altered and abnormal patterns occur. Cardiovascular-related sudden death is a leading cause of mortality during sports. ECG interpretation in athletes therefore requires careful analysis to properly distinguish changes due to physiological adaptations from those suggestive of underlying pathology. The present study describes ECG changes and attempts to identify possible adaptive and maladaptive changes among a cohort of elite athletes of different sports in Port Harcourt, Nigeria. Subjects and Methods: Cross-sectional prospective study involving 339 subjects (16–35 years) comprising 170 athletes (63 males and 107 females) and 169 nonathletes (74 males and 95 females) serving as control were recruited. Anthropometric parameters and blood pressure indices were determined and physical examination conducted to exclude associated comorbidities. Electrocardiographic parameters were determined through standard procedure using a resting 12-lead ECG. Results: No significant differences were observed for anthropometric parameters and blood pressure indices between male athletes and male nonathletes; although, female athletes had significantly higher weight and body mass index than female nonathletes. Irrespective of gender, athletes had significantly lower heart rate, T-axis and significantly higher QT-intervals compared to nonathletes; with lower P-axis and higher PR-interval among male athletes compared to male nonathletes. The left ventricular hypertrophy was the most prevalent abnormality among athletes. Conclusion: Changes described are due majorly to physiologic adaptation. However, some mal adaptations suggestive of risk factors for possible sudden cardiac death were identified. We advise sports physicians to carefully interpret ECG features of athletes to distinguish physiological changes related to athletic conditioning from findings suggestive of pathology.

Inter-observer agreement in athletes ECG interpretation using the recent international recommendations for ECG interpretation in athletes among observers with different levels of expertise.

IntroductionInternational criteria for the interpretation of the athlete’s electrocardiogram (ECG) have been proposed. We aimed to evaluate the inter-observer agreement among observers with different levels of expertise.MethodsConsecutive ECGs of Swiss elite athletes (≥14 years), recorded during routine pre-participation screening between 2013 and 2016 at the Swiss Federal Institute of Sports were analysed. A medical student (A), a cardiology fellow (B) and an electrophysiologist (C) interpreted the ECG’s independently according to the most recent criteria. The frequencies and percentages for each observer were calculated. An inter-observer reliability analysis using Cohen Kappa (κ) statistics was used to determine consistency among observers.ResultsA total of 287 ECGs (64.1% males) were analysed. Mean age of the athletes was 20.4±4.9 years. The prevalence of abnormal ECG findings was 1.4%. Both, normal and borderline findings in athletes showed moderate to good agreement between all observers. κ scores for abnormal findings resulted in excellent agreement (κ 0.855 in observer A vs C and B vs C to κ 1.000 in observer A vs B). Overall agreement ranged from moderate (κ 0.539; 0.419–0.685 95% CI) between observer B vs C to good agreement (κ 0.720; 0.681–0.821 95% CI) between observer A vs B.ConclusionsOur cohort of elite athletes had a low prevalence of abnormal ECGs. Agreement in abnormal ECG findings with the use of the recently published International recommendations for ECG interpretation in athletes among observers with different levels of expertise was excellent. ECG interpretation resulted in moderate to good overall agreement.

Comments on the New International Criteria for Electrocardiographic Interpretation in Athletes

Sudden cardiac death is the most common medical cause of death during the practice of sports. Several structural and electrical cardiac conditions are associated with sudden cardiac death in athletes, most of them showing abnormal findings on resting electrocardiogram (ECG). However, because of the similarity between some ECG findings associated with physiological adaptations to exercise training and those of certain cardiac conditions, ECG interpretation in athletes is often challenging. Other factors related to ECG findings are race, age, sex, sports discipline, training intensity, and athletic background. Specific training and experience in ECG interpretation in athletes are therefore necessary. Since 2005, when the first recommendations of the European Society of Cardiology were published, growing scientific evidence has increased the specificity of ECG standards, thus lowering the false-positive rate while maintaining sensitivity. New international consensus guidelines have recently been published on ECG interpretation in athletes, which are the result of consensus among a group of experts in cardiology and sports medicine who gathered for the first time in February 2015 in Seattle, in the United States. The document is an important milestone because, in addition to updating the standards for ECG interpretation, it includes recommendations on appropriate assessment of athletes with abnormal ECG findings. The present article reports and discusses the most novel and relevant aspects of the new standards. Nevertheless, a complete reading of the original consensus document is highly recommended.

Comentarios a los nuevos criterios internacionales para la interpretación del electrocardiograma del deportista

Sudden cardiac death is the most common medical cause of death during the practice of sports. Several structural and electrical cardiac conditions are associated with sudden cardiac death in athletes, most of them showing abnormal findings on resting electrocardiogram (ECG). However, because of the similarity between some ECG findings associated with physiological adaptations to exercise training and those of certain cardiac conditions, ECG interpretation in athletes is often challenging. Other factors related to ECG findings are race, age, sex, sports discipline, training intensity, and athletic background. Specific training and experience in ECG interpretation in athletes are therefore necessary. Since 2005, when the first recommendations of the European Society of Cardiology were published, growing scientific evidence has increased the specificity of ECG standards, thus lowering the false-positive rate while maintaining sensitivity. New international consensus guidelines have recently been published on ECG interpretation in athletes, which are the result of consensus among a group of experts in cardiology and sports medicine who gathered for the first time in February 2015 in Seattle United States. The document is an important milestone because, in addition to updating the standards for ECG interpretation, it includes recommendations on appropriate assessment of athletes with abnormal ECG findings. The present article reports and discusses the most novel and relevant aspects of the new standards. Nevertheless, a complete reading of the original consensus document is highly recommended.Full English text available from: www.revespcardiol.org/en

International recommendations for electrocardiographic interpretation in athletes.

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.

Performance of the Lausanne questionnaire and the 2010 European Society of Cardiology criteria for ECG interpretation in athletes

In recent years various proposals and subsequent changes have been made to improve pre-participation screening (PPS) methods. This study examines the Lausanne questionnaire and the old and new ESC criteria for a positive electrocardiogram (ECG) in athletes. Retrospective cohort study. All consecutive students undergoing a PPS between January and July 2011 were included. The screening consisted of the Lausanne questionnaire, a physical examination, and a 12-lead ECG. A total of 561 students were screened. A total of 310 students (55%) answered positively to one or more of the Lausanne questions and 49 (9%) of these abnormalities were assessed as medically relevant. Physical examination was abnormal in nine (1.6%) students. In total, 120 (21%) ECGs were found positive following the old criteria. According to the new criteria, 68 (12%) ECGs were found positive. Four (already known) congenital cardiac disorders and four new diagnoses were found. When using the new ECG criteria, two out of four new cardiovascular diagnoses would have been missed. The use of the Lausanne questionnaire provides many irrelevant findings causing unnecessary positive screening outcomes. With the new ESC criteria for a positive 12-lead ECG in athletes, the number of false-positive screenings greatly decrease: however, at the cost of an increase in the number of false-negatives. To reach a conclusive judgment on the cost:benefit ratio of PPS, it is necessary to have a validated discriminating questionnaire, specific medical knowledge of PPS and clear definitions of a normal and abnormal 12-lead ECG in athletes.

EKG-Diagnostik bei Leistungssportlern

In young competitive athletes sudden cardiac death frequently occurs as a tragic first manifestation of clinically inapparent underlying structural or electrical cardiac disorders. An increased risk may be reflected by typical electrocardiogram (ECG) alterations preceding symptoms but a correct interpretation is often challenging due to a high prevalence of training-related ECG alterations in competitive athletes mimicking such disorders. Misinterpretation may thus result in either unnecessary disqualification from competitive sports or continuation despite an increased risk or extensive diagnostic work-ups yielding additional equivocal findings. However, as observed in large athlete cohorts in recent years a variety of ECG alterations, such as isolated increased QRS voltage, early repolarization, sinus bradycardia, first degree AV block or incomplete right bundle branch block, represent common variants of ECGs of athletes reflecting physiological and training-related cardiac adaptations. These alterations do not usually require further diagnostic evaluation. In contrast, alterations such as repolarization abnormalities, complete bundle branch block, prolonged QT intervals or pathological Q waves, are strongly suggestive of underlying disorders and require further evaluation even in asymptomatic athletes. Thus, the ECG plays a pivotal role in the prevention of sudden cardiac death in competitive athletes. The present article summarizes current recommendations for the interpretation of athlete ECGs regarding the differentiation between physiological or pathological cardiac adaptation.