Editor's Note: Commentary based on Aziz PF, Sweeten T, Vogel RL, et al. Sports participation in genotype positive children with long qt syndrome. JACC Clin Electrophysiol 2015;1:62-70.

History

It has been five decades since Jervell and Lange-Nielsen reported the first case of long QT syndrome (LQTS).¹ Since then, knowledge on the topic has massively expanded. The first Bethesda Conference was held in 1985, during which a group of experts published guidelines on sports eligibility for patients with underlying cardiovascular diseases that put them at increased risk of sudden cardiac death (SCD). Recognizing the lack of compelling evidence for restricting concealed LQTS patients, the 26th Bethesda Conference recommendations were revised in 2005 to allow genotype positive-phenotype negative LQTS individuals to participate in competitive sports, except those with LQTS type 1 who remain prohibited from swimming participation. Furthermore, the recommendations continue to restrict the following patients from participating in competitive sports: 1) all phenotype positive LQTS individuals, regardless of genotype subtype or electrocardiogram (ECG) findings; 2) asymptomatic patients with QTc prolongation on ECG (>470 ms in males and >480 ms in females); and 3) patients with implantable cardioverter-defibrillators (ICD)s.² On the other hand, for European athletes with LQTS, sports participation is still regarded as taboo irrespective of their genotype/phenotype relationship or clinical history.³

Epidemiology

Due to the new advances in genetic techniques and the establishment of family cascade screening, many more asymptomatic individuals are being diagnosed with LQTS. Considering a prevalence of one in 2,000⁴ to one in 5,000⁵ and excluding genotype positive-phenotype negative LQTS patients (20% of total affected individuals) and based on the current U.S. population, the 36th Bethesda Conference guidelines would restrict 10,000 to 30,000 children between the ages 0 to 17 years from competitive sports.

Scope of the Problem

Although rare, sudden cardiac death (SCD) in the young has a devastating impact on parents, family members, and the community owing to its association with the healthiest and most dynamic patient population and to the loss of many productive years. The majority of sudden cardiac deaths among predisposed young individuals occur during sport activities secondary to the significant physiological and hemodynamic changes associated with exertion.^6,7 In addition, exercise has been identified as the major trigger for cardiac-related events in certain LQTS subtypes.⁸ These observations have fueled the sports restriction discussion and have led to prohibiting athletes with LQTS from sports participation. However, studies evaluating the efficacy of beta-blocker therapy have demonstrated a substantial decrease in the risk of syncopal episodes as well as fatal and near-fatal events, especially among the "high-risk" population.^8-11 Unfortunately, the current published 36th Bethesda Conference guidelines do not entirely account for the significant protective benefit of beta-blocker therapy.

As evident in the massive amounts of literature on the psychological consequences of physical inactivity and its huge impact on the patient's quality of life, it appears that restricting LQTS patients unnecessarily from sports participation is not without a price.^12,13 The primary aim of pediatric electrophysiologists is to prevent arrhythmia-induced SCD in vulnerable individuals; however, the decision should be individualized in order to minimize risks associated with physician recommendations. Whether this risk is avoidable in all patients with LQTS is a debatable question; nonetheless, based on recent research, there is hope that this may be possible in some patients and under certain circumstances.

Recent Research

Apart from retrospective studies from two institutions, there are no other data examining the prevalence and outcome of sports participation in patients with LQTS. Johnson and Ackerman identified a total of 130 patients, between the ages of six to 40 years, who chose to remain active in competitive sports. The majority were asymptomatic at the time of the diagnosis. None of the patients had a sport-related event, and only one of the genotype positive-phenotype positive patients had an appropriate ICD shock during sports activity in the setting of non-compliance with beta-blocker. There were no observed deaths over 650 athlete-years of follow-up.¹⁴

Similarly, the Children's Hospital of Philadelphia (CHOP) has engaged parents of children with LQTS in an informed decision-making process. During the study period, 103 genotype positive LQTS patients participated in competitive (26%) or recreational (75%) sports, of whom 55% were diagnosed through familial cascade genetic screening.¹⁵ The majority of the participants were diagnosed with LQTS type I (58%), and 6% had ICDs. In contrast to the published Bethesda Conference guidelines, 46% engaged in competitive sports (17%: 4th Bethesda Conference guideline, 58%: 2nd Bethesda Conference guideline, 3%: 1st Bethesda Conference guideline). None of the patients had tachyarrhythmic death/arrest, syncope, or appropriate/inappropriate shock delivery during or after sports.

This data suggests that some adequately-treated, genotype positive school-aged children with LQTS can engage safely in competitive and recreational sport activities. Results should be carefully interpreted, as the majority of our studied patients were asymptomatic at the time of the diagnosis, possibly representing a "low-risk" category. However, the authors of this Expert Analysis article suspect that based on current practice, the wide availability of cascade genetic screening and the development of inherited arrhythmia clinics, our study population reflects that of the current era, highlighting the need to re-examine sports recommendations that are based on data from an earlier era. Another significant fact that should not be overlooked is that most of the patients participated in recreational sports making it difficult to quantify the level and intensity of exertion and, therefore, the degree of catecholamine surge. Similar to the event documented by Johnson's paper, one of our LQTS type I patients had an appropriate ICD shock for torsades de pointes while running a few feet in the backyard after discontinuing beta-blocker therapy. Although none of the patients in our cohort required automated external defibrillator (AED) activation during sport activities, until further evidence is available, patients with LQTS who choose to participate in sports should continue to have access to an AED.

Our Approach/Recommendations

Because we believe that the patient and his/her family have the right to participate in this complex decision, we have allowed self-determination in our LQTS population at the Cleveland Clinic. Based on the CHOP and the Mayo Clinic experiences, we recommend that decision making in relation to sports activity be individualized while incorporating patients'/parents' desires in the process. Experts in pediatric inherited arrhythmias should find a balance between keeping patients with LQTS safe while providing the best quality of life. Above and beyond all other considerations, liberalization of sport participation should only be considered in individuals who: 1) are highly compliant with therapy, 2) maintain adequate hydration and electrolyte status, 3) avoid prolonging QTc medications, and 4) have access to an AED during sports competition.

By no means do we suggest allowing all patients with LQTS, or those who are at low risk, a "life-time clearance" to participate in all static and dynamic sport activities. Nonetheless, we highly recommend that these patients are followed at a tertiary center with an expert in inherited arrhythmias who can meticulously risk stratify each patient and devise an individualized plan that patients and families are part of and are comfortable with.

Gaps in Knowledge and Future Implications

When trying to answer the question regarding LQTS patients' eligibility for sports participation, pediatric arrhythmia specialists should discuss the answers to the following questions with parents and patients: 1) what is the risk of sports related SCD events; is it highly unacceptable; 2) What are the risks of sport restriction in LQTS diagnosed patients; and 3) Do risks outweigh benefits? Until further studies are available on this highly controversial topic, we recommend an individualized approach after a well-informed and extensive discussion with the patient and caregivers to determine what is in the best interest of the patient.

References

1. Jervell A, Lange-Nielsen F. Congenital deaf-mutism, functional heart disease with prolongation of the Q-T interval and sudden death. Am Heart J 1957;54:59-68.
2. Zipes DP, Ackerman MJ, Estes NA 3rd, Grant AO, Myerburg RJ, Van Hare G. Task Force 7: arrhythmias. J Am Coll Cardiol 2005;45:1354-63.
3. Pelliccia A, Fagard R, Bjornstad HH, et al. Recommendations for competitive sports participation in athletes with cardiovascular disease: a consensus document from the Study Group of Sports Cardiology of the Working Group of Cardiac Rehabilitation and Exercise Physiology and the Working Group of Myocardial and Pericardial Diseases of the European Society of Cardiology. Eur Heart J 2005;26:1422-45.
4. Schwartz PJ, Stramba-Badiale M, Crotti L, et al. Prevalence of the congenital long-QT syndrome. Circulation 2009;120:1761-7.
5. Goldenberg I, Moss AJ. Long QT syndrome. J Am Coll Cardiol 2008;51:2291-300.
6. Corrado D, Basso C, Schiavon M, Thiene G. Does sports activity enhance the risk of sudden cardiac death? J Cardiovasc Med 2006;7:228-33.
7. Maron BJ. Sudden death in young athletes. N Engl J Med 2003;349:1064-75.
8. Schwartz PJ, Priori SG, Spazzolini C, et al. Genotype-phenotype correlation in the long-QT syndrome: gene-specific triggers for life-threatening arrhythmias. Circulation 2001;103:89-95.
9. Liu JF, Jons C, Moss AJ, et al. Risk factors for recurrent syncope and subsequent fatal or near-fatal events in children and adolescents with long QT syndrome. J Am Coll Cardiol 2011;57:941-50.
10. Moss AJ, Zareba W, Hall WJ, et al. Effectiveness and limitations of beta-blocker therapy in congenital long-QT syndrome. Circulation 2000;101:616-23.
11. Hobbs JB, Peterson DR, Moss AJ, et al. Risk of aborted cardiac arrest or sudden cardiac death during adolescence in the long-QT syndrome. JAMA 2006;296:1249-54.
12. Johnson JN, Ackerman MJ. Return to play? Athletes with congenital long QT syndrome. Br J Sports Med 2013;47:28-33.
13. Fletcher GF, Balady G, Blair SN, et al. Statement on exercise: benefits and recommendations for physical activity programs for all Americans. Circulation 1996;94:857-862.
14. Strong WB, Malina RMM, Blimkie CJ, et al. Evidence based physical activity for school-age youth. J Pediatr 2005;146:732-7.
15. Aziz PF, Sweeten T, Vogel RL, et al. Sports participation in genotype positive children with long qt syndrome. JACC Clin Electrophysiol 2015;1:62-70.

Keywords: Arrhythmias, Cardiac, Athletes, Caregivers, Catecholamines, Child, Death, Sudden, Cardiac, Decision Making, Defibrillators, Implantable, Electrocardiography, Electrolytes, Follow-Up Studies, Genetic Testing, Genotype, Heart Conduction System, Hemodynamics, Long QT Syndrome, Parents, Phenotype, Physical Exertion, Prevalence, Quality of Life, Retrospective Studies, Running, Specialization, Swimming, Syncope, Torsades de Pointes

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