World Anti-Doping Agency (WADA) and International Olympic Committee (IOC) list of prohibited substances and methods and their cardiovascular effects

The abuse of doping substances is prevalent in sports and in society at large. Doping substances are also present in a substantial fraction of nutritional supplements. They can cause severe side effects. This chapter is focused on cardiovascular side effects. Androgenic anabolic steroids can induce left ventricular hypertrophy, heart fibrosis, and systolic and diastolic dysfunction, and has been associated with dyslipidaemia, endothelial dysfunction, and coronary artery disease. Beta-2 agonists can induce chronotropic and inotropic effects, QT prolongation, palpitations, arrhythmias and sudden cardiac death. Erythropoietin can induce hypertension and embolism. Use of banned substances and methods in sports, i.e. doping, is prohibited, unethical, and dangerous. Research efforts in sports sciences and sports medicine are needed to prevent and treat doping abuse and to help athletes be successful without the need for doping.

Cardiac safety at sports events: the medical action plan

The cardiac-specific medical services plan, in and around a sports stadium or arena, should be carefully undertaken and individualized, in order to ensure safe, effective, and coordinated management of any sudden cardiac arrest (SCA). This is ensured practically by tailoring the designated number and skills of on-duty health-care personnel and by having adequate and appropriate medical equipment, effective communication systems, and the emergency medical service transportation logistics required to initiate cardiopulmonary resuscitation (CPR) and defibrillation within the first 3–5 minutes after SCA, regardless of the size or type of sport environment. The planning should be written down in a medical action plan (MAP) which should be communicated to all relevant and appropriate officials, health-care personnel, and, where relevant, participants and spectators. Relevant contact information regarding activation of the necessary emergency medical services, listing the sport environment health-care personnel, and continuous education and skills training are vital parts of the MAP.

Resuscitation on the field: basic and advanced life support and automatic external defibrillators

Resuscitation on the playing field is at least as important as screening in the prevention of death. Even if a screening strategy is largely effective, individuals will suffer sudden cardiac arrests. Timely recognition of a cardiac arrest with rapid implementation of cardiopulmonary resuscitation (CPR) and deployment and use of automated external defibrillators (AEDs) will save lives. Basic life support, including CPR and AED use, should be a requirement for all those involved in sports, including athletes. An emergency action plan is important in order to render advanced cardiac life support and arrange for transport to medical centres.

Monitoring exercise programmes and improving cardiovascular performance

Cardiovascular exercise performance is associated with lower morbidity and mortality. In addition to maximal load, heart rate, and peak oxygen consumption, cardiopulmonary exercise testing and lactate analyses can provide relevant information on cardiovascular performance, diagnosis, exercise prescription, and monitoring of exercise programmes based on submaximal parameters. Using submaximal thresholds has the advantage that the prescription and effect of exercise training are directly linked to the underlying energy metabolism and therefore can reveal the specific needs of the individual. There are several methods ofr strength testing that are all based on maximum parameters and should be chosen according to the best-fit principle to the underlying strength training programme. In addition, new media such as wearables, innovative gadgets and telemonitoring have become increasingly popular in recent years and can be used to monitor the exercise training sessions, providing information for evaluation and adjustment of training if necessary.

The risk, aetiology, clinical features, management, and prevention of exercise-related sudden cardiac death and acute cardiac events in adult athletes

Regular physical activity reduces atherosclerotic coronary artery disease (CAD) events including acute myocardial infarction (AMI) and sudden cardiac death (SCD). Conversely, vigorous exercise acutely and transiently increases the risk of both these CAD events in adult athletes with known or occult CAD. CAD is the cause of most exercise-related SCDs in adult athletes. Exercise-related AMIs are typically caused by atherosclerotic plaque rupture and acute thrombosis, whereas exercise-related SCD can be caused by both plaque rupture and exercise-induce ischaemia. The management of athletes with CAD requires aggressive risk factor reduction plus an assessment of risk for an acute cardiac event based on exercise testing, ventricular function measurement, and an assessment of electrical stability. Whether or not an athlete should return to competition after a CAD event is a joint decision made by the athlete and the clinician based on the risks and benefits of athletic participation for that athlete.

Indications for genetic testing in athletes and its application in daily practice

Genetic information is fundamental for the management of patients with primary arrhythmia syndromes (e.g. long QT syndrome or catecholaminergic polymorphic ventricular tachycardia) and cardiomyopathies (e.g. arrhythmogenic right ventricular cardiomyopathy or hypertrophic cardiomyopathy) which increase the risk of sudden cardiac death. Importantly, molecular testing can play a pivotal role in establishing a clinical diagnosis of an inherited cardiovascular disease, particularly when the phenotype in unclear and overlaps with the normal adaptations induced in the heart by chronic exercise. However, the decision to undergo genetic testing needs to be justified on a clinical basis and handled by professionals who are capable of framing the results in the correct perspective. In this chapter we will answer the following questions. When should genetic testing be performed in athletes? Which genetic tests should be requested for athletes? What impact should a positive genetic result have on sports eligibility?

Ambulatory (24-hour Holter monitoring, event recorders) and signal-averaged ECG for arrhythmia registration in the athlete’s heart

Systematic physical exercise leads to structural, functional, and electrical cardiovascular changes summarized in the term ‘athlete’s heart’. Arrhythmias that are common features in the resting ECG of otherwise healthy athletes may be an expression of the athlete’s heart, but on the other hand may be caused by underlying cardiac pathology, opening up a grey zone of diagnostic uncertainty. Differentiating adaptive changes from pathological cardiac conditions is of great clinical importance because some cardiomyopathies are leading causes of sudden cardiac death in athletes. In addition, there is increasing evidence that excessive endurance training may induce intermittent atrial arrhythmias, which can be hard to detect by resting ECG. Therefore this chapter will highlight 24-hour Holter monitoring, event recorders, and signal-averaged ECGs in the emerging field of ambulatory arrhythmia registration as part of the diagnostic work-up of athlete’s heart.

The athlete’s heart in children and adolescents

Athlete’s heart occurs in childhood but is less well understood than in adults. In children, exercise-related cardiac remodelling occurs but with more heterogeneity than in adults. It can be difficult to distinguish age-related cardiac maturation, exercise-related adaptation, and the early manifestation of cardiac disease such as cardiomyopathy. The initial assessment of a child with possible athlete’s heart includes a detailed history (medical, family, and exercise), comprehensive physical examination, ECG, and echocardiography. Congenital and structural heart disease should be excluded and the pubertal stage should be considered when interpreting findings. Investigations should be interpreted according to somatic size (using centiles) and pubertal stage rather than chronological age. Ethnic variations in physiology should be identified. If in doubt, child athletes with possible ethnically related changes should be followed up until maturity. T-wave inversion in anteroseptal leads is usually normal before puberty but abnormal after puberty. Lateral T-wave inversion is usually abnormal at any age. Voltage criteria for left ventricular hypertrophy are common in healthy child athletes. The presence of pathological Q waves, T-wave inversion, and ST-segment depression requires exclusion of cardiomyopathy. Most child athletes’ heart chamber size is within the normal reference ranges for age/gender, but hypertrophic cardiomyopathy should be considered in adolescent athletes with wall thickness >12mm (girls >11mm).

Structural and functional adaptations in the athlete’s heart

Cardiac changes in athletes have been described for more than a century, with initial observations derived by chest percussion and chest X-rays. Recent advances in cardiovascular imaging have allowed morphological and functional assessment of cardiac remodelling associated with systematic training, and consequently over the last decades a vast literature has been assembled focused on the constellation of alterations known as ‘athlete’s heart’. This chapter provides means for understanding the determinants, extent, and upper limits of cardiovascular adaptation in athletes. A detailed overview of all cardiac chambers is provided to help the physician to recognize the physiological limits of cardiovascular remodelling.

Diagnosis and management of hypertension in athletes

Arterial hypertension is the most common cardiovascular abnormality reported in the setting of pre-participation screening of large athletic populations. Identification of high blood pressure values during the evaluation of an athlete may raise concern about appropriate management and indications with respect to competitive sport participation, representing a potential cause for exclusion from competitive sports. The diagnostic approach, risk stratification, and clinical management of hypertension in athletes are extensively reviewed and discussed in this chapter.