The American College of Cardiology (ACC) recently established a Sports and Exercise Council; one objective of this council is to define the essential skills necessary to practice effective sports cardiology. The purpose of this document is to highlight the basic fund of knowledge and skills required for the effective practice of sports cardiology. The following are points to remember:

1. Four fundamental domains of clinical knowledge are critical to the care of competitive athletes and highly active people (CAHAP):
   • Differentiation of exercise-induced cardiac remodeling from cardiovascular pathology.
   • Evaluation of the symptomatic CAHAP.
   • Management of the CAHAP with known cardiovascular disease.
   • Collaborative pre-participation cardiovascular screening.
2. Fundamental clinical exercise physiology: All forms of physical activity and competitive athletics involve some combination of static and dynamic exercise.
   • Static activity is characterized by short and forceful skeletal muscle contractions. The primary role of the cardiovascular system during static exercise is to maintain cardiac output in the setting of increased afterload, accomplished by increasing myocardial contractility.
   • Dynamic/endurance activity is characterized by repetitive, often rhythmic contraction and relaxation of large skeletal muscle groups. The primary cardiovascular response to dynamic exercise is to increase cardiac output.
3. Exercise-induced cardiac remodeling: Repetitive participation in vigorous physical exercise stimulates adaptive changes in cardiovascular structure and function (exercise-induced cardiac remodeling).
   • Dichotomization of sports into either static or dynamic is overly simplistic; most sporting disciplines involve some element of both static and dynamic stress.
   • In general, biventricular and biatrial volume challenges associated with dynamic physiology sports lead to chamber dilation, whereas pressure challenge associated with static sports leads to left ventricular (LV) wall thickening with minimal effects on the other three cardiac chambers.
4. Diagnostic findings in athletes:
   • Electrocardiogram (ECG): Cardiovascular adaptations to exercise commonly manifest on the ECG, and overlap with patterns suggesting underlying cardiovascular disease. Contemporary athlete ECG criteria divide findings into benign, adaptive patterns (including sinus bradycardia, early repolarization, prominent QRS voltage, and incomplete right bundle branch block) and those that are more suggestive of cardiovascular pathology.
   • Noninvasive imaging: Exercise-induced cardiac remodeling results in thickening of the LV wall and dilation of the LV chamber.
     • LV wall thickness in the range of 11-13 mm is common among CAHAP.
     • Eccentric LV hypertrophy occurs most commonly in association with sports with both high dynamic and high static physiology, often accompanied by physiologic dilation of the right ventricle (RV) and both atria.
     • Mild concentric LV hypertrophy may develop among CAHAP participating in high static/low to moderate dynamic physiology.
     • LV diastolic function in CAHAP should be normal or enhanced.
     • Exercise-induced cardiac remodeling can result in three distinct “gray zone” findings with challenges in distinguishing normal adaptation from pathology: LV wall thickening, LV dilation, and RV dilation.
5. Evaluation of symptomatic CAHAP: The evaluation of CAHAP with symptoms suggestive of underlying cardiovascular disease requires the integration of basic principles of general cardiology and exercise physiology, with a comprehensive understanding of issues unique to this population.
   • Chest pain: Noncardiac causes of chest pain (gastrointestinal, pulmonary, musculoskeletal) are common across all ages of CAHAP. Among CAHAP <35 years old, cardiovascular disease accounts for only about 6% of chest pain; in contrast, atherosclerotic cardiovascular disease (ASCVD) is the dominant cause of exertional chest pain in CAHAP >35 years old. Symptoms of ischemia may vary between younger and older CAHAP.
   • Syncope: Causes of collapse include cardiac and neutrally mediated syncope, heat stroke, hyponatremia, “exercise associated collapse,” and seizure. Syncope in young CAHAP most commonly is neutrally mediated, and occurs in the immediate post-exercise period or at times unrelated to exercise.
   • Palpitations: Palpitations that occur in the absence of triggers such as excitement, fear, or psychological stress; or during exercise; are more likely to be caused by arrhythmia rather than sinus tachycardia. CAHAP with palpitations during exercise should undergo cardiac imaging and exercise testing.
   • Impaired exercise capacity: Exercise intolerance can be related to a subjective complaint after comparison to peers, or with objective evidence of declining exercise capacity. Evaluation requires a comprehensive, collaborative approach that includes athletic trainers, coaches, internists, primary care sports medicine providers, and other medical specialists.
6. Management of CAHAP with established cardiovascular diagnosis: Health and safety should be prioritized over athletic goals.
   • Competitive sports eligibility criteria: Comprehensive US-based recommendations were first proposed by the 36th Bethesda Conference in 1985; the most recent update, co-sponsored by the American Heart Association (AHA) and ACC, was published in 2015.
   • Diseases of the heart muscle: Hypertrophic cardiomyopathy is associated with increased risks of sudden death during exercise; routine vigorous exercise may increase the risk of future heart failure and arrhythmia in CAHAP with arrhythmogenic RV cardiomyopathy. Myocarditis is associated with an increased risk of arrhythmia during sports participation.
   • Electrical heart disease: Ion channel abnormalities may increase the risk of malignant, potentially fatal arrhythmia during sports participation. Although long QT syndrome has been associated with increased risk of arrhythmia, observational data suggest that the risk of death might be low among athletes who continue sports participation in conjunction with appropriate disease-specific treatment.
   • Intracardiac device considerations: The indications for implantable cardioverter-defibrillator (ICD) implantation in CAHAP should rely on standard recommendations; it is inappropriate to pursue ICD implantation in CAHAP that do not meet standard criteria simply to facilitate “safer” sports participation. Current recommendations permit consideration for sports participation among athletes with an ICD.
   • ASCVD: Although routine physical exercise has favorable effects on traditional risk factors and reduces the incidence of ASCVD, it does not confer immunity. In CAHAP, ASCVD may be driven by traditional risk factors, or by other mediators including macronutrient diet, psychological stress, and perhaps exercise itself. Antiplatelet and high-dose statin therapies are appropriate, although statin-related muscle side effects are common.
   • Hypertension: Hypertension is common among CAHAP. Bilateral brachial artery blood pressures should be assessed at each clinical encounter. When pharmacotherapy is indicated, vasodilators (angiotensin-converting enzyme inhibitors, dihydropyridine calcium channel blockers) should be prioritized over diuretics or medications with negative inotropic effects.
   • Atrial fibrillation: Aging CAHAP are probably at increased risk of atrial fibrillation and flutter. In those who opt to pursue a strategy of rhythm control, options including antiarrhythmic medications and ablation should be considered in light of relative risks and benefits.
7. Pre-participation cardiovascular screening:
   • Rationale: Detection of heart diseases associated with risk for sudden death provides an opportunity to reduce adverse events through disease-specific therapy and/or sports restriction.
   • Recommendations: Current AHA/ACC recommendations endorse a strategy of focused medical history physical examination. Although a screening ECG may detect more cases of occult disease, it also carries an increased rate of false-positive results; current US recommendations discourage mandatory ECG screening for athletes and nonathletic youthful populations.
   • Sports cardiologists: Sports cardiologists who participate in pre-participation screening should be versed in current societal recommendations, aware of areas of controversy, familiar with all aspects of the sponsoring school or organization, collaborative with key stakeholders, and capable of evaluation of athletes with abnormal findings.

Keywords: Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Atherosclerosis, Athletes, Atrial Fibrillation, Blood Pressure, Bradycardia, Bundle-Branch Block, Calcium Channel Blockers, Cardiac Imaging Techniques, Cardiac Output, Cardiomyopathy, Hypertrophic, Chest Pain, Death, Sudden, Defibrillators, Implantable, Diet, Diuretics, Electrocardiography, Exercise, Exercise Test, Heart Defects, Congenital, Heart Failure, Hydroxymethylglutaryl-CoA Reductase Inhibitors, Hypertension, Hypertrophy, Hyponatremia, Long QT Syndrome, Myocarditis, Myocardium, Physical Examination, Primary Health Care, Risk Assessment, Risk Factors, Seizures, Sports, Sports Medicine, Syncope, Tachycardia, Sinus, Vasodilator Agents, Primary Prevention

< Back to Listings