Preparticipation Screening Of Athletes Research Articles

The role of coronary CT angiography in athletes.

The sudden death of a young or high-level athlete or adolescent during recreational sports is one of the events with the greatest impact on public opinion in modern society. Sudden cardiac death (SCD) is the principal medical cause of death in athletes and can be the first and last clinical presentation of underlying disease. To prevent such episodes, pre-participation screening has been introduced in many countries to guarantee cardiovascular safety during sports and has become a common target among medical sports/governing organizations. Different cardiac conditions may cause SCD, with incidence depending on definition, evaluation methods, and studied populations, and a prevalence and etiology changing according to the age of athletes, with CAD most frequent in master athletes, while coronary anomalies and non-ischemic causes prevalent in young. To detect silent underlying causes early would be of considerable clinical value. This review summarizes the pre-participation screening in athletes, the specialist agonistic suitability visit performed in Italy, the anatomical characteristics of malignant coronary anomalies, and finally, the role of coronary CT angiography in such arena. In particular, the anatomical conditions suggesting potential disqualification from sport, the post-treatment follow-up to reintegrate young athletes, the diagnostic workflow to rule-out CAD in master athletes, and their clinical management are analyzed.

Fragmented QRS complexes in veteran athletes

Abstract Background QRS fragmentation (fQRS), characterized by multiple peaks within the QRS, is considered an adverse risk marker that may indicate underlying myocardial fibrosis and has been implicated in cardiomyopathies. The presence of fQRS is often noted in pre-participation screening of athletes. In this study, we aimed to investigate the prevalence and clinical significance of fQRS in a cohort of ostensibly fit veteran athletes (VA). Methods We recruited 314 predominantly Caucasian VA's with a history of endurance exercise and no traditional risk factors for coronary artery disease. Participants underwent a 12-lead electrocardiogram, cardiopulmonary exercise testing (CPET), 24-hour Holter monitoring, and cardiac magnetic resonance imaging (CMR). fQRS was categorized as >2 consecutive leads using established criteria (1). Results fQRS in 2 or more contiguous leads was identified in 12% of VA's. The presence of fQRS was more prevalent in males and increased with age (p < 0.05). There were no significant differences in ECG conduction indices. When CMR parameters were considered, the presence of fQRS was associated with increased left ventricular (LV) mass index and increased right ventricular (RV) function. There was no relationship with the presence of late gadolinium enhancement. Athletes with fQRS achieved a significantly lower predicted peak VO2 and trended towards lower peak resistance on CPET. No relationship was observed with total ventricular premature beat count or the presence of complex ectopy on 24-hour Holter monitoring. Conclusions fQRS in 2 or more contiguous leads is commonly present amongst male Caucasian VA’s, and its prevalance increases with age. It is associated with greater LV mass and increased RV ejection fraction. Athletes with fQRS may achieve a lower percentage predicted VO2 max compared to those without. Furthermore, FQRS did not predict late gadolinium enhancement, increased VPB count or complex ectopy.Comparing VAs with FQRSQRS-fragmentation patterns (Das et al)

Cost-effectiveness and diagnostic accuracy of focused cardiac ultrasound in the pre-participation screening of athletes: the SPORT-FoCUS Study.

The role of Pre-participation screening (PPS) modalities in preventing sudden cardiac death (SCD) in athletes is debated due to a high false positive rate. Focused Cardiac Ultrasound (FoCUS) has shown higher sensitivity and specificity, but its cost-effectiveness remains uncertain. This study aimed to determine the diagnostic performance and cost-effectiveness of FoCUS use in PPS. 2111 athletes (77.4% male, mean age 24.9±15,2years) underwent standardized family and medical history collection (MH), physical examination (PEX), resting ECG, FoCUS (10min/5views-protocol), comprehensive Echocardiography and exercise stress test(EST). We prospectively evaluated three PPS incremental models: Model-A = standardized MH and physical examination; Model-B = Model-A plus resting and stress-ECG; Model-C = Model-B plus FoCUS (10min/5views-protocol). We determined their incremental diagnostic accuracy and cost-effectiveness ratio. 30 athletes were diagnosed with a cardiac condition associated with SCD: 3 were identified by Model-A, 14 by Model-B, 13 athletes by Model-C. The introduction of FoCUS markedly increased the Sensitivity of PPS, compared with model-A and model-B (Sensitivity 94% vs. 19% vs. 58%, Specificity 93% vs. 93% vs. 92%). The total screening cost (TSC) were: Model-A 35.64Eur, Model-B 87.68Eur and Model-C 120.89Eur. Considering the sole conditions at risk of SCD, the Incremental Cost Effectiveness Ratio was 135.62Eur for model-B and 114.31 for model-C. The implementation of FoCUS into the PPS allows to identify a significantly greater number of athletes at risk of SCD and markedly lowers the false negative rate. Furthermore, the incorporation of FoCUS into the screening process has shown to be cost-effective.

Preparticipation Screening of Athletes: The Prevalence of Positive Family History

Sudden cardiac death (SCD) is a leading cause of death among athletes, and those with a positive family history (FH) of SCD and/or cardiovascular disease (CVD) may be at increased risk. The primary objective of this study was to assess the prevalence and predictors of positive FH of SCD and CVD in athletes using four widely used preparticipation screening (PPS) systems. The secondary objective was to compare the functionality of the screening systems. In a cohort of 13,876 athletes, 1.28% had a positive FH in at least one PPS system. Multivariate logistic regression analysis identified the maximum heart rate as significantly associated with positive FH (OR = 1.042, 95% CI = 1.027-1.056, p < 0.001). The highest prevalence of positive FH was found using the PPE-4 system (1.20%), followed by FIFA, AHA, and IOC systems (1.11%, 0.89%, and 0.71%, respectively). In conclusion, the prevalence of positive FH for SCD and CVD in Czech athletes was found to be 1.28%. Furthermore, positive FH was associated with a higher maximum heart rate at the peak of the exercise test. The findings of this study revealed significant differences in detection rates between PPS protocols, so further research is needed to determine the optimal method of FH collection.

Sudden cardiac death in athletes – can we prevent it?

Introduction and purpose: Sudden cardiac death (SCD) is a rare condition, however it is the leading medical cause of death in population of athletes. This study reviews the epidemiology and common causes of SCD in this group. The literature on the role of pre-participation screening and of the other preventive measures was also reviewed. Review methods: A review of the available literature on sudden cardiac death in athletes was conducted using PubMed and Google Scholar databases. Description of the state of knowledge: SCD is the leading cause of death in athletes. However, the incidence is difficult to estimate and varies in different populations. The etiology is age-dependent, in young individuals the most common cause of sudden cardiac death are hypertrophic cardiomyopathy and congenital coronary artery anomalies. In the older athlete population (over 35 years old) atherosclerotic coronary artery disease is the main cause. Screening process varies between countries and besides taking the medical history and physical examination can involve electrocardiogram, echocardiography and other examinations. Conclusions: A review of the following studies has shown, that pre-participation screening of athletes may help to reduce the incidence of sudden death. Equal focus should be put on the availability of medical facilities during sports events, including experienced medical team and access to automated external defibrillation.

Pre-participation cardiovascular screening in athletes with a focus on Asia

Pre-participation screening (PPS) in young competitive athletes aims to identify conditions associated with sudden cardiac death (SCD) in this population, with a view to appropriate management and potential mitigation of risk. A medical history questionnaire and physical examination are standard components of a PPS programme, whereas controversy still exists regarding mandatory utilisation of resting 12-lead electrocardiogram as a screening tool. Apart from a landmark study from Italy attributing the reduction of SCD rates in athletes to the implementation of a mandatory PPS programme, there remains no additional compelling evidence for similar outcomes to date. Nonetheless, comprehensive PPS programmes when carried out systematically, are efficacious in detection of cardiac pathology and cost-effective. While the incidence rate of SCD in athletes from Western countries is estimated to be around 1:50,000, comparable data in Asian athletes remain lacking. Prospective registries are much needed to accurately determine the magnitude of this issue in Asia and recent recommendations on PPS in young Asian athletes have been published to increase awareness and encourage collaboration. To further reduce SCD events, prompt recognition of sudden cardiac arrests and early defibrillation are vital components in the spectrum of SCD prevention. This review aims to outline the rationale, current status and efficacy of PPS in athletes, with a focus on Asia.

Blood Pressure Response and Vascular Function of Professional Athletes and Controls.

Workload-indexed blood pressure response (wiBPR) to exercise has been shown to be superior to peak systolic blood pressure (SBP) in predicting mortality in healthy men. Thus far, however, markers of wiBPR have not been evaluated for athletes and the association with vascular function is unclear. We examined 95 male professional athletes (26±5 y) and 30 male controls (26±4 y). We assessed vascular functional parameters at rest and wiBPR with a graded bicycle ergometer test and compared values for athletes with those of controls. Athletes had a lower pulse wave velocity (6.4±0.9 vs. 7.2±1.5 m/s, p=0.001) compared to controls. SBP/Watt slope (0.34±0.13 vs. 0.44±0.12 mmHg/W), SBP/MET slope (6.2±1.8 vs. 7.85±1.8 mmHg/MET) and peak SBP/Watt ratio (0.61±0.12 vs. 0.95±0.17 mmHg/W) were lower in athletes than in controls (p<0.001). The SBP/Watt and SBP/MET slope in athletes were comparable to the reference values, whereas the peak SBP/Watt-ratio was lower. All vascular functional parameters measured were not significantly correlated to the wiBPR in either athletes or controls. In conclusion, our findings indicate the potential use of the SBP/Watt and SBP/MET slope in pre-participation screening of athletes. Further, vascular functional parameters, measured at rest, were unrelated to the wiBPR in athletes and controls.

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.

The Role Of Coronary Ct In Preparticipation Screening Of Masters Athletes

Introduction: Preparticipation screening of athletes over the age of 35 (Masters athletes, MA) is one of the rising problems facing sports cardiologists. The incidence of sudden death within this group of patients is low and statistically correlated to the presence of coronary arteriosclerosis. In the light of this data, the evaluation of coronary circulation through coronary computed tomographic angiography (CCTA) is progressively changing the diagnostic and management approach regarding this patient population.

Possible new options and benefits to detect myocarditis, right ventricular remodeling and coronary anomalies by echocardiography in systematic preparticipation screening of athletes

Exclusion of cardiac abnormalities should be performed at the beginning of the athlete’s career. Myocarditis, right ventricular remodeling and coronary anomalies are well-known causes of life-threatening events of athletes, major cardiovascular events and sudden cardiac death. The feasibility of an extended comprehensive echocardiographic protocol for the detection of structural cardiac abnormalities in athletes should be tested. This standardized protocol of transthoracic echocardiography includes two- and three-dimensional imaging, tissue Doppler imaging, and coronary artery scanning. Post processing was performed for deformation analysis of all compounds including layer strain. During 2017 and 2018, the feasibility of successful image acquisition and post processing analysis was retrospectively analyzed in 54 male elite athletes. In addition, noticeable findings inside the analyzed cohort are described. The extended image acquisition and data analyzing was feasible from 74 to 100%, depending on the used modalities. One case of myocarditis was detected in the present cohort. Coronary anomalies were not found. Right ventricular size and function were within normal ranges. Isovolumetric right ventricular relaxation time showed significant regional differences. One case of hypertrophic cardiomyopathy and two subjects with bicuspid aortic valves were found. Due to the excessive cardiac stress in highly competitive sports, high-quality and precise screening modalities are necessary, especially with respect to acquired cardiac diseases like acute myocarditis and pathological changes of left ventricular and RV geometry. The documented feasibility of the proposed extended protocol underlines the suitability to detect distinct morphological and functional cardiac alterations and documents the potential added value of a comprehensive echocardiography.

Pre-participation screening of the athletes in Turkey: approach of primary care physicians

Abstract Background The pre-participation screening is crucial as the risk of sudden death for competitive athletes is higher than that of non-athletes. In Turkey, screening could be performed at the primary health care setting both by family medicine specialists (FMSs) and by general practitioners (GPs). Although there is a guideline, there is no legal regulation for the process. The aim of this study is to evaluate the approach of primary care physicians in pre-participation screening. Methods An online questionnaire based on the Turkish Medical Association (TMA) guideline, and the 14-item Screening Guideline of the American Heart Association (AHA) was delivered to primary care physicians. Knowledge, experience and approach of the physicians were assessed. Self-confidence, application of AHA criteria, accurate referral ratios and further test requests were taken as outcome measures. Descriptive and inferential analyzes were performed and p &amp;lt; 0.05 was considered significant. Results Of 214 participants, 39.3% were women, the average age was 44.9 years, the average work experience was 7.9 years. 89.7% of the participants were aware of their authorization, 90.2% had previously given this report, but only 6.5% feels confident. Only 13.1% knows the presence of TMA guideline, and only 23.8% states being educated on the subject at any part of their career. More than 60% of the participants consider further testing necessary in addition to medical history and physical examination. Blood and urine test requests were significantly more for GPs compared to FMSs (p = 0.026, p = 0.011). Accurate referral decision ratio was only 59.3% with no difference between FMSs and GPs (p = 0.216). Work experience had no effect on any of the outcomes. Conclusions As the legal regulations and awareness of the guideline are insufficient, pre-participation screening is not standardized, and this increases tendency for further testing or referral. Key messages The pre-participation screening of athletes in Turkey is not standardized among primary care physicians. Further testing request ratio is high and accurate referral ratio is low.

Point-of-Care Ultrasound as a Component of Preparticipation Screening of Athletes: A Systematic Review.

This review examined whether the addition of point-of-care ultrasound (POCUS) to electrocardiography (ECG)-inclusive preparticipation screening strategies has the potential to reduce false-positive results and detect diseases associated with sudden cardiac death that may not be identified through current modalities. Five studies, representing 2646 athletes, demonstrated that ECG-inclusive preparticipation screening strategies resulted in positive results in 19.9% of the cohort. With the addition of POCUS, positive results were reduced to 4.9%, and 1 additional condition potentially associated with sudden cardiac death was identified. The magnitude of positive results with POCUS may be reduced if current ECG criteria were applied.

Technically Adequate Images for Preparticipation Screening Echocardiography Can Be Obtained by Novices After a Single Day of Training.

Echocardiography-naïve physicians were trained in a 1-day course to determine whether they could obtain images adequate for preparticipation screening in athletes. Twenty-six physicians with no previous experience in echocardiography were trained to perform preparticipation screening echocardiography during a 6-hour course. Each image was rated for its technical quality on a diagnostic adequacy score. The time taken to perform the images was also evaluated. The images obtained a median score of 3 (interquartile range, 2-4), which was considered adequate for preparticipation screening. Video clips achieved a higher rating than the still images, with a median score of 4 (interquartile range, 3-4). The best-performing 50% of the participants obtained adequate images for screening 95% of the time after the initial training. Considering the group overall, 79.2% of all video clips were adequate. The median time to perform the scans was 39 seconds. The correlation between the time and adequacy score showed that the quickest novices were also able to obtain the best images. It is feasible to use novice sonographers to perform preparticipation screening echocardiography provided that the skill of the candidates is assessed after training, and competent individuals are selected. Video images should be used rather than still images.

Preparticipation Athletic Screening, Supervision, and Disqualification of Student- Athletes: Physician Trepidation of Legal Liability

Physicians participate in screening, routine medical supervision, and the disqualification process of high school and college student athletes. Physicians and schools evaluating student-athletes for athletic participation should understand the meticulous medical process necessary to make eligibility/disqualification decisions, and the associated liability issues. It is the responsibility of a team physician to take a lead role in the sports teams’ medical evaluation process. The first duty of a team physician and institution is to protect the health and well being of their collegiate student athletes. The potential liability associated with the evaluation process requires that high schools and institutions of higher education work with their physicians to develop sound and reasonable administrative strategies regarding participation in athletics. Reducing the liability risk requires an understanding and compliance with the available medical guidelines and evolving judicial framework. It is imperative physicians understand case law and available medical guidelines. As medical professional standards evolve, so will responsibilities under legal standards. Liability issues regarding the preparticipation screening of athletes, their medical supervision, and their eligibility for and disqualification from participation are of increasing concern to the practicing medical community. Court cases involving athletic field morbidity and mortality have elucidated an evolving legal framework related to the alleged failure to properly diagnose, treat, qualify, or disqualify individuals from competitive sport. This manuscript will highlight liability cases involving cardiac, neurological, musculoskeletal, and heat illness issues. These cases will identify the importance of the standard of care in evaluation/disqualification, adherence to medical guidelines, and the need for diligent follow up in determining return to play issues.

AMSSM Position Statement on Cardiovascular Preparticipation Screening in Athletes: Current Evidence, Knowledge Gaps, Recommendations, and Future Directions: Erratum.

Cardiovascular (CV) screening in young athletes is widely recommended and routinely performed before participation in competitive sports. While there is general agreement that early detection of cardiac conditions at risk for sudden cardiac arrest and death (SCA/D) is an important objective, the optimal strategy for CV screening in athletes remains an issue of considerable debate. At the center of the controversy is the addition of a resting electrocardiogram (ECG) to the standard preparticipation evaluation using history and physical examination. The American Medical Society for Sports Medicine (AMSSM) formed a task force to address the current evidence and knowledge gaps regarding preparticipation CV screening in athletes from the perspective of a primary care sports medicine physician. The absence of definitive outcomes-based evidence at this time precludes AMSSM from endorsing any single or universal CV screening strategy for all athletes including legislative mandates. This statement presents a new paradigm to assist the individual physician in assessing the most appropriate CV screening strategy unique to their athlete population, community needs, and resources. The decision to implement a CV screening program, with or without the addition of ECG, necessitates careful consideration of the risk of SCA/D in the targeted population and the availability of cardiology resources and infrastructure. Importantly, it is the individual physician's assessment in the context of an emerging evidence base that the chosen model for early detection of cardiac disorders in the specific population provides greater benefit than harm. American Medical Society for Sports Medicine is committed to advancing evidenced-based research and educational initiatives that will validate and promote the most efficacious strategies to foster safe sport participation and reduce SCA/D in athletes.

Variation in Preparticipation Screening Medical Questionnaires and Physical Examinations Across Canadian Universities

Pre-participation screening of athletes to prevent sudden cardiac arrest or death is endorsed by international guidelines. Standardized histories and physical examinations are recommended to optimize effectiveness. To assess current screening practices across Canada in the university athlete population, we sought to analyze the preparticipation screening form of all universities. A comparative analysis to recommendations from the American Heart Association (AHA), European Society of Cardiology (ESC), and the Preparticipation Physical Evaluation (PPE-4) was conducted. Pre-participation forms from 30 of 56 U Sports universities were obtained. Adherence to published guidelines was highly variable. Ten percent strictly followed any of the 3 guideline recommendations, and only 43% contained at least 75% of the recommended items. Average percentage adherence to AHA and ESC guidelines was statistically significantly higher than adherence to the PPE-4 (62.2% and 66.1%, respectively, vs 52.7%, P < 0.001). Family history of common cardiac conditions predisposing athletes to sudden cardiac death and family history of sudden or unexpected death was omitted in 80% and 30% of forms, respectively. Recommendations for examining for stigmata of Marfan syndrome and assessment of femoral pulses was absent on more than 70% of forms. Although there is great controversy regarding the benefits and impact of screening, our results suggest that Canadian universities are conducting pre-participation screening although in a highly variable manner. Incomplete and variable screening questionnaires employed by Canadian universities may negatively affect the potential to identify athletes with underlying disease. We recommend that, if pre-participation screening is performed, a guideline-based questionnaire be used to optimize accuracy.

Pre-participation screening of asymptomatic athletes : "Don't do stupid stuff".

Catastrophic events, be it traffic accidents, natural disasters or homicides, always lead to scrutiny. Could we have seen the event coming and could it have been prevented? In the case of a sudden cardiac arrest of a seemingly healthy athlete the public outcry is not any different. Despite an intrinsic appeal for screening to prevent similar events, there is no evidence that justifies routine cardiovascular pre-participation screening of athletes. On balance, cardiovascular screening in athletes will most likely do more harm than good. Fatal exercise-related cardiac arrests do not occur very often. The true diagnostic yield of the pre-participation evaluation is not known and once a cardiac condition has been identified, the most appropriate intervention is often unclear. It follows that pre-participation screening of large groups of athletes without known cardiac disease will inevitably result in many false positive findings, while at the same time providing a false sense of security to those screened negative. Except for compelling reasons (e. g. cascade screening, research settings, professional athletes), physicians should not engage in routine examination of asymptomatic athletes to prevent cardiac events.

Young athletes with ventricular premature beats: Continuing or not intense training and competition?

Isolated ventricular premature beats (VPBs) are commonly found during pre-participation screening in athletes. Currently, the debate about the role of detraining in reducing the number of VPBs is still open. This study evaluated the arrhythmic risk in a population of young competitive athletes who showed VPBs during eligibility evaluation and that did not undergo detraining but continued practicing competitive sports. 3746 consecutive subjects underwent pre-participation screening. Athletes who showed VPBs were selected and underwent second level evaluation (Echocardiogram, 24hour Holter ECG and Exercise test). Athletes were re-evaluated after a follow-up period (6-48months) while they continued practicing competitive sports. 5.3% of the whole population showed ventricular arrhythmias. 73% of the subjects showed isolated VPBs. 88% of the subjects showed monomorphic VPBs, and 12% of athletes showed polymorphic VPBs. At echocardiogram, there was not any pathology which contraindicated competitive sport activity. At 24hour Holter ECG recording, mean number of daily VPBs was 1592±3217 (range 0-16678). At holter ECG follow-up (16±12months), the median number of VPBs decreased from 93 (IQR 20-3065) to a new value of 72 (IQR 2-1299). Continuing competitive sport in subjects with ventricular arrhythmias even though frequent but with a low grade of complexity and without structural cardiomyopathy does not increase sudden death risk.

Prevention of sudden death in adolescent athletes: Incremental diagnostic value and cost-effectiveness of diagnostic tests.

Introduction Pre-participation screening in athletes attempts to reduce the incidence of sudden death during sports by identifying susceptible individuals. The objective of this study was to evaluate the diagnostic capacity of the different pre-participation screening points in adolescent athletes and the cost effectiveness of the programme. Methods Athletes were studied between 12-18 years old. Pre-participation screening included the American Heart Association questionnaire, electrocardiogram, echocardiogram, and stress test. The cost of test was established by the Catalan public health system. Results Of 1650 athletes included, 57% were men and mean age was 15.09 ± 1.82 years. Positive findings were identified as follows: in American Heart Association questionnaire 5.09% of subjects, in electrocardiogram 3.78%, in echocardiogram 4.96%, and in exercise test 1.75%. Six athletes (0.36%) were disqualified from participation and 10 (0.60%) were referred for interventional treatment. Diagnostic capacity was assessed by the area under the curve for detection of diseases that motivated disqualification for sport practice (American Heart Association questionnaire, 0.55; electrocardiogram, 0.72; echocardiogram, 0.88; stress test, 0.57). The cost for each athlete disqualified from the sport for a disease causing sudden death was €45,578. Conclusion The electrocardiogram and echocardiogram were the most useful studies to detect athletes susceptible to sudden death, and the stress test best diagnosed arrhythmias with specific treatment. In our country, pre-participatory screening was cost effective to detect athletes who might experience sudden death in sports.

Use of the electrocardiogram in pre-participation screening of athletes: For or against?

Use of the electrocardiogram in pre-participation screening of athletes: For or against?