Syncope as a Warning Symptom of Sudden Cardiac Death in Athletes

2017 ACC/AHA/HRS Guideline for the Evaluation and Management of Patients With Syncope: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society

“…However, syncope during exercise is a much more compelling symptom and can be a harbinger of SCD. 712,713 Syncopal episodes first require a personal and family history to evaluate precipitating causes and benign conditions, particularly volume depletion and vasovagal activity. Concomitant illnesses, especially viral infections, should be investigated and an ECG obtained.…”

Syncope in the young athlete: Assessment of prognosis in subjects with hypertrophic cardiomyopathy

“…2 Its incidence is estimated at 6.2/ 1000 person-years, increasing with age but with a peak of first faints in patients aged 10-30 years. 3,12,22 In the Framingham study, in a population of 7814 individuals over a 26-year follow-up, the incidence of syncope was similar between men and women, but almost double in participants with a history of cardiovascular disease. 3 The risk of recurrence was particularly high among participants with cardiac syncope, and this was associated with increased risk of premature death and cardiovascular events.…”

“…1,2,4,6 Nevertheless, little is known about its incidence in athletes. 12 Colivicchi et al reported a cohort of 7568 athletes undergoing preparticipation screening, 15 of whom 474 (6.2%) reported at least one syncope in the preceding five years. Most of these (86.7%) were reported as unrelated to exercise and occurring during ordinary daily activities, 12% were post-exertional and usually occurred soon after cessation of exercise, and only 1.3% of cases were during exercise (with diagnoses of HCM, right ventricular outflow tract tachycardia and exercise-induced neurally mediated syncope).…”

“…6,25 Even in the absence of the typical risk factors associated with HCM, extrapolation of risk level from non-athletes to highly trained competitive athletes is tenuous due to the unstable electrophysiologic substrate and its propensity for potentially lethal ventricular arrhythmias during the physiological stresses inherent to exercise (e.g., catecholamine surge and disturbances in blood volume, electrolytes and hydration). 12,26 Although the basic causes of syncope in HCM can be broadly divided into primary hemodynamic mechanisms (such as reflex syncope) and arrhythmias, in most cases it results from a combination of factors which influence the circulatory balance. 27,28 Prognosis Over the last few years, due to better diagnostic procedures, there has been increasing recognition of the impact that prolonged training has on cardiac remodeling.…”

“…8,9 Young healthy individuals who report a TLoC during exercise require a focused and thorough assessment to identify potentially lethal cardiac disorders. 7,12,14 The purpose of this study was to review the literature on syncope in young athletes and its relationship to patients with HCM, in order to enable accurate assessment of prognosis and the possibility of resuming competitive sports. After screening of titles and abstracts for an initial assessment of eligibility, the full text of potentially relevant articles was obtained and reviewed for final decisions on inclusion.…”