With the growing number of young people who want to participate in competitive sports, cardiologists are increasingly facing the question posed in the title of this paper in daily practice. In this era of evidence-based medicine, sports cardiology still represents uncharted waters. Although both European and American health authorities agree that the pre-participation evaluation (PPE) of a young person is important to prevent sudden cardiac death (SCD) related to excessive exercise and has ethical, medical and legal aspects, there is a continuing debate about how to do it [1, 2]. A proper clinical history and physical exam are essential and should probably be done with questionnaires, although the evidence is lacking about the ideal questionnaire. A detailed long list may give more clues about probable underlying cardiovascular disease (CVD) at the risk of unnecessary further testing and disqualifications; however, it may be impractical in daily practice while the most important clues may be lost in the detail. A shorter list may be more practical and should include the essential red flags.
It is also well described in the literature that a history and physical only screening is less sensitive than an electrocardiogram (ECG) to detect important cardiac diseases such as cardiomyopathies or primary arrhythmic syndromes, which are the most important causes of SCD in the young .
Not only is the ECG a fundamental test in cardiology practice, but it is cheap, feasible and widely accessible. However, interpreting an athlete’s ECG may be challenging because of the unique features of an athlete’s heart. Hence, the attending physician, who might not have sufficient training or experience in the proper interpretation of an athlete’s ECG, may do more harm than good .
The aim of this paper is to review current literature and search for a proper answer.
Why is the answer important?
Regular exercise is related to a cardiovascular and all-cause mortality benefit as well as improved wellbeing and should be promoted by physicians, although there is a small risk that intense exercise may induce fatal arrhythmias in predisposed people. Even though it happens rarely, SCD of a young, apparently healthy individual on the athletic field is a catastrophic event and may have a negative impact on exercise habits in the general population. The true incidence of SCD in the young athletic population is not exactly known due to the inefficient detection of sports-related SCD.
As a general estimate, 1-2 of 100,000 young athletic individuals (aged between 12 to 35 years) die suddenly every year ; however, the incidence may vary from 1 in a million to 1 in 5,000, depending on the age, gender, race and type of the sport . Age is an important factor both for the incidence (5-10 times higher in athletes over 35 years than younger ones) and aetiology of SCD . There is a clear gender gap for SCD, with the incidence rate being more than three times higher in males than in female athletes [1-3]. Black athletes have a higher incidence than white athletes, which is defined as being a 3.2 times higher risk in US college athletes [1,3]. Basketball and soccer players have a higher risk than athletes in other types of sport.
The bottom line to remember is that being male, of the black race, or participating in basketball and soccer, confers a higher risk [1,3].
The aetiology of SCD in young athletes is well described and has a mainly genetic or congenital basis. The prevalence of heart diseases related to SCD is estimated as being 0.3% . Arrhythmogenic cardiomyopathy (formerly known as arrhythmogenic right ventricle cardiomyopathy [ARVC]) is the leading cause of SCD in young athletes in European countries, while hypertrophic cardiomyopathy (HCM) is the number one cause in the USA, which may be related to different genetic features of populations or to different pre-participation screening protocols [1,4].
Congenital coronary artery anomalies (CCAA) are another important cause: a left coronary artery arising abnormally from the right aortic sinus with an interarterial route between aorta and pulmonary artery is the most common CCAA related to SCD in young sports participants. Myocarditis, dilated cardiomyopathy, premature coronary atherosclerosis, aortic rupture or dissection in the presence of Marfan syndrome are also reported as causes of SCD in young athletes [1,5]. The presence of a bicuspid aortic valve and mitral valve prolapse are relevant valvulopathies among young adults . Ventricular pre-excitation and primary inherited arrhythmia syndromes such as long or short QT syndromes, catecholaminergic polymorphic ventricular tachyarrhythmia (CPVT) and Brugada syndrome are also responsible for SCD in young athletes . Although not a cardiac disease, commotio cordis, defined as SCD of an athlete with a structurally normal heart after a blunt, non-penetrating chest trauma, is not as rare as previously thought, especially among young adolescent males .
Recent data from autopsy series of athletes, who had been evaluated before competition and died suddenly, indicate that autopsy-negative sudden unexplained death (AN-SUD) or sudden arrhythmic death syndrome (SADS) which defines a structurally normal heart is the leading diagnosis in young competitive athletes (reported as being up to 44% in some series) [2,3,7]. This finding suggests that no screening protocol will diagnose all cases and prevent SCD 100%.
How should we answer the question?
To avoid and possibly prevent SCD of an athlete, a pre-participation evaluation is necessary; however, the best method is still debatable [1,2,4,8,9]. The aim in the screening process should be not only to prevent SCD of the athlete, but also to avoid unnecessary disqualification or unnecessary advanced diagnostic studies. Therefore, a balance between benefit and possible harm (detection of underlying CVD and expensive diagnostic work-up with unnecessary disqualification) is needed in the screening protocol.
With knowledge of the incidence and aetiology of SCD, a series of questions and tests may help to identify major CVD among apparently healthy young individuals. There are many questionnaires from different organisations with the same aim of unveiling an underlying, previously undiagnosed cardiac disorder, which may result in a possible life-threatening situation with excessive exercise.The common ground of these questionnaires is to seek the presence of any symptoms related to a significant heart disease [1,8].
A pre-participation screening questionnaire may consist of a short series of questions or the list may be more comprehensive; however, in the era of evidence-based medicine, we do not have the right answer as to which form would be more beneficial. A short series of questions is easier to check and can be done routinely, although asking the right questions is fundamental. Defining the right questions to detect an underlying and possibly lethal cardiac condition is also not so simple while avoiding false-positive results. All the existing questionnaires focus on genetic inheritance of important CVD and relevant symptoms such as syncope, which may be related to a life-threatening arrhythmia; however, they are expressed as expert consensus opinion and never validated.
A longer list of history questions may be used, although there is no evidence that a longer list would be safer or more beneficial than a short list, while a long list may provoke more false-positive results. Although they have been debated because of their validation, low sensitivity and high false-positive results, questionnaires are needed in order to standardise the pre-participation screening process [8-12]. As all the pre-existing questionnaires recommend, the absence or presence of a previous cardiovascular diagnosis or any cardiac treatment should be questioned first. Any syncope, dizziness, palpitation, angina or inappropriate shortness of breath with exercise is important, because most of the causes of SCD appear with these symptoms. Unless considered neurocardiogenic (vasovagal), syncope is an important clinical symptom. Further testing is recommended especially if there is a relation with exercise.
Also, the exercise capacity of the young individual should be questioned. Hence, in the presence of a cardiovascular disorder, athletic individuals could decrease their exercise level to avoid the symptoms. Family history has importance because of the genetically inherited nature of CVD which may lead to SCD. An early unexpected death of a family member or any diagnosed heart disease, especially primary arrhythmic syndromes and cardiomyopathies, should be asked into carefully [5,8-10].
The physical exam of the young participant should include auscultation of the heart to identify heart murmurs indicative of valvular pathology and any irregularity of heart rhythm. Checking peripheral arterial pulses to exclude coarctation is important. The presence of phenotypical features of Marfan syndrome should be evaluated. A proper blood pressure measurement of the athletic participant is another crucial part of the physical exam and has to be done preferably from both arms [5,8-10].
The most important and debated test in the evaluation of an athletic participant is the electrocardiogram (ECG). Actually, both the USA and European countries agree that an ECG is a valuable test in pre-participation evaluation, and definitely outperforms “history plus physical only” screening; however, the main concern here is the accurate interpretation of the athlete’s ECG without causing unnecessary disqualification and unnecessary further diagnostic testing. An ECG is capable of capturing almost 60% of CVD related to SCD on the field, such as arrhythmogenic or hypertrophic cardiomyopathy and electrical disorders of the heart. An ECG screening in experienced hands outperforms clinical history and a physical exam in all statistical analysis [1,2,10-14], hence the term “experienced hands” should be underlined [15-17].
The interpretation of an athlete’s ECG is not simple, not even for a cardiologist, without further training, because of the overlapping of some physiological and pathological changes. Physicians without further training have unacceptably high rates of false-positive results, which leads to unnecessary advanced diagnostic testing and disqualification. Because the number of physicians trained in interpreting an athlete’s ECG is limited in most countries, a standardisation of athletic ECG assessment is necessary. A standardisation may balance the favourable effects of ECG screening while avoiding false-positive and negative results. Several studies have shown that a standardised algorithm will decrease false-positive results, even if the physician has little or no expertise [15-17].
To increase specificity (false-positive detection) and sensitivity (disease detection) of ECG screening, a great deal of effort has been made since 2005, and in 2017 “the International Recommendations for Electrocardiographic Interpretation in Athletes” was published [5,15,18,19]. The latest international recommendations have defined a borderline category besides normal and pathological changes of an athlete’s ECG to decrease false-positive results in order to avoid unnecessary further work-up and disqualification.
With all the scientific evidence, a standardised checklist/questionnaire which includes pathological ECG changes along with history and physical exam sections could help physicians in the decision-making process [8,10-14]. A proposed questionnaire, which summarises clinical history, physical exam and pathological ECG changes, is given in Table 1. In mass screening, echocardiography does not increase diagnostic sensitivity and should be reserved only for further work-up [1,8,20].
The checklist/questionnaire is needed to guide and standardise the pre-participation screening process. Although family and personal history questionnaires have significant false-positive results, combining these with the standardised ECG criteria according to the latest recommendations would help physicians in the decision-making process.
The short table that follows is built around the most relevant questions that could reveal an underlying cardiovascular disease as well as addressing pathological ECG changes.
Any positive answer by a young person would require further investigation [5,8,12].
Table 1. Athletic participant checklist/questionnaire.
Further investigation is required in the presence of a positive answer
Any previous cardiovascular diagnosis or any cardiac treatment
|Any syncope or near-syncope||Ο||Ο|
|Palpitation, angina or inappropriate shortness of breath with exercise||Ο||Ο|
Family historyFurther investigation is required in the presence of a positive answer
|An early unexpected death (related to heart disease) of a family member||Ο||Ο|
|Any diagnosed inherited heart disease especially primary arrhythmic syndromes and cardiomyopathies||Ο||Ο|
Physical examFurther investigation is required in the presence of a positive finding
|Any murmur or irregularity by auscultation||Ο||Ο|
|Absence of femoral pulse||Ο||Ο|
|Phenotypic features of Marfan syndrome||Ο||Ο|
|Blood pressure >140/90 mmHg||Ο||Ο|
ElectrocardiogramFurther investigation is required in the presence of 1 positive criterion in Group 1 and 2 positive criteria in Group 2
|Group 1 criteria|
T-wave inversion (TWI)(except TWI in V1-4 in black athletes and TWI in V1-3 in adolescent athletes younger than 16 years)
Pathological Q-wavesQ/R ratio ≥0.25 or ≥40 ms in duration in 2 or more leads
Complete left bundle branch block
|QRS duration ≥140 ms||Ο||Ο|
|Prolonged QT interval||Ο||Ο|
|Brugada Type 1 pattern||Ο||Ο|
|Profound sinus bradycardia (<30/min)||Ο||Ο|
|PR interval ≥400 ms||Ο||Ο|
|Mobitz Type II - 2nd degree AV block||Ο||Ο|
|3rd degree AV block||Ο||Ο|
|≥2 premature ventricular contractions||Ο||Ο|
|Atrial or ventricular tachyarrhythmias||Ο||Ο|
|Group 2 criteria|
|Left axis deviation||Ο||Ο|
|Left atrial enlargement||Ο||Ο|
|Right axis deviation||Ο||Ο|
|Right atrial enlargement||Ο||Ο|
|Complete right bundle branch block||Ο||Ο|
If there is no red flag with the clinical history, physical exam and ECG, it is logical to allow participation in competitive sports; however, the presence of abnormal findings requires further investigation. As an emerging trend underlined in many guidelines, a “shared decision-making” process should be an important part of the PPE. Hence, for ethical, medical and legal aspects of PPE, it is important to inform the athletic participant, although with the screening process the risk is never zero, though very small.
In a certain sense sports cardiology is unique in relation to other cardiology subspecialties by the lack of large prospective randomised controlled trials. For the most part recommendations are based on expert consensus reports, small series with long follow-ups or observational studies. Because of this, and the subsequent “grey areas” in sports cardiology, some tolerance for flexibility and individual responsibility is needed . Also, the athletic participant has to be informed about important warning signs, such as dizziness, inappropriate palpitation, shortness of breath or angina during exercise, which may be related to an adverse cardiac event. They should be advised to stop playing and seek a medical consultation when such an event occurs.
Cardiovascular safety during sports activities and prevention of SCD are common goals among medical and sports authorities, although there are still a lot of grey areas in the evaluation of a young person for competitive sports. Because of the overwhelming health benefits of exercise such as decreased total and cardiovascular mortality, exercise training should be encouraged as a welfare policy.
Although intense exercise may trigger SCD, especially in a predisposed individual, the risk is very low and comparable to lightning strike fatality . To balance benefits and possible harm, accurate evaluation of an individual before participation in a competition is crucial. Increasing awareness of PPE and standardising the process among attending physicians may help to improve outcomes. To standardise and generalise the PPE process, a short list is more practical and may be better in order to avoid false-positive results, although it may also result in missing some important clues about underlying CVD. However, combining essential questions with an ECG for PPE may increase disease detection during the process.
In addition, a long list might produce undesirable false positive results, and it is not clear that a longer list provides better diagnostic power or more security than a short list.
As captured in the second-best statement in medicine after “primum non nocere”, a “try to keep it simple” style short list may help to extend the usage of an accurate PPE, even by inexperienced physicians.