27507
2014
CPJXXX10.1177/0009922814527507WomackClinical Pediatrics
Commentary
Proper Screening for Sudden Cardiac Death in the Young Athlete
Clinical Pediatrics 2015, Vol. 54(3) 208–211 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0009922814527507 cpj.sagepub.com
Jason Womack, MD1 Sudden cardiac death (SCD) in the young athlete is a devastating event. It often occurs without warning and is the most common cause of death in the athlete under 40 years of age.1 There is much debate on the best practice in which to detect athletes at risk for SCD. A cardiac health history incorporated into a preparticipation physical exam is widely accepted but its effectiveness is limited. Use of more advanced cardiac studies such as electrocardiogram and echocardiogram is highly debated.
Epidemiology Death from exertion is an unfortunate risk associated with physical activity. The etiologies of these incidents are related to heat illness, trauma, and underlying medical conditions. Cardiovascular disease is the leading cause of sudden death in the young athlete. The incidence of SCD is quoted to be 1/160 000 in the general population of the United States.1 There is debate to the validity of this number as most reports are from media outlets as there is no national or international reporting system. Studies of smaller cohorts of patients have yielded higher incidences of SCD. A study of military recruits showed an incidence of 1/9000,2 and a study of NCAA athletes showed an incidence of 1/44 000.3 A study of SCD in the Veneto region of Italy yielded an incidence of 1/28 000.4 In the athlete 40 years of age or older, coronary artery disease is the leading cause of SCD. Under the age of 40, structural or electrical abnormalities of the cardiovascular system that have gone undiagnosed are the leading cause of SCD.
Structural Causes of SCD Ideally, physicians would have an effective way to discover silent etiologies that put an athlete at risk for a cardiac event. Unfortunately, the ability to detect some of the most common forms of SCD in the athlete is very limited. The majority of these problems can present with SCD as their first symptom. SCD can be caused by a number of intrinsic and extrinsic factors. The most common cause of SCD in the United States is hypertrophic cardiomyopathy (HCM).5
It has a prevalence of 1 in 500 adults. Despite this, it is unlikely to present itself clinically in the majority of cases.6 It is inherited genetically in an autosomal dominant fashion and has variable penetrance. The morphology of HCM is that of a hypertrophied left ventricle in the absence of associated cardiac or systemic disease. Patients with HCM may or may not present with a heart murmur depending on the degree of left ventricular outflow obstruction.6 Electrocardiogram (EKG) is often abnormal in HCM, and echocardiogram shows characteristic left ventricular wall enlargement.6 The histological appearance of HCM is that of a disordered cellular architecture.7 Sudden death due to arrhythmia from HCM is the most likely symptomatic manifestation to occur in children and young adults and suspected to be increased in the presence of mild exertion.8,9 Arrythmogenic right ventricular cardiomyopathy (ARVC) is another congenital heart abnormality that leads to SCD in the young athlete. A study of sudden death in the Veneto region of Italy determined there was a relatively high prevalence of this disorder in its population.10,11 Its prevalence is 1:1000 to 1:5000 in the general population and is inherited in an autosomal dominant pattern.12,13 In ARVC there is a congenital abnormality in the histological make up of the right ventricular that leads to a replacement of the normal cardiovascular myocytes with fibrofatty tissue. This disorganization leads to interruption of normal electrical impulses that can become the nidus for conduction abnormalities.13 Another cause of SCD in the young athlete is from congenital coronary artery anomalies. Episodic cardiac ischemia, infarction, or both is thought to occur in the setting of an anomalous coronary artery.14 There are many mechanisms that are hypothesized for an anomalous coronary artery to lead to cardiac ischemia, but most episodes of SCD seem to occur in patients with an anomalous left main coronary artery and occur during 1
Rutgers University Robert Wood Johnson Medical School, New Brunswick, NJ, USA Corresponding Author: Jason Womack, Department of Family Medicine and Community Health, Robert Wood Johnson Medical School, Rutgers University, 1 RWJ Pl, MEB 2nd Fl, New Brunswick, NJ 08903, USA. Email: [email protected]
209
Womack physical activity.15 Although difficult to detect clinically, surgical intervention can correct the problems of anomalous coronary arteries. Marfans syndrome is a genetic disease of connective tissue that leads to an error in the body’s production of fibrillin. Fibrillin is important in the integrity of connective tissues. The cardiovascular system is one of the many organ systems affected by the lack of fibrillin, particular the integrity of blood vessel walls. The aortic arch is at risk for dilation that can ultimately lead to aneurysm and rupture. Exercise puts a greater stress on the aorta and increases the risk of this catastrophic event.
Electrical Abnormalities There are many conditions that primarily expose people to a variety of arrhythmias without any structural abnormalities of the heart. There are different mechanisms that may predispose these people to have arrhythmia. It is often difficult to identify patients with this predisposition as they have not had time to declare symptoms or initial symptoms could result in death. Wolf–Parkinson–White syndrome is characterized by a preexcitation pathway connecting the atria and the ventricles. Under normal conditions, the ventricles are protected by the refractory period of the AV node. In the presence of an accessory pathway, the ventricles can be exposed to high atrial rates that could cause the ventricles to degenerate into a lethal arrhythmia.16 This is particularly problematic in people with supraventricular arrhythmias such as atrial fibrillation. Long QT syndrome is a genetic disorder that leads to prolonged repolarization of the ventricles of the heart. It has an incidence in the general population of about 1:3000 to 1:5000 and is inherited in an autosomal dominant pattern. The underlying disturbance is within the ion channels responsible for repolarization of the heart. This disturbance can lead the heart into ventricular arrhythmias and SCD.17 Approximately 13% of patients with untreated Long QT will go on to SCD.18 Brugada syndrome is a pattern of cardiac electrocardiographic activity represented by right bundle branch block and ST segment elevation in the right precordial leads. Patients with this disorder have a large incidence of having arrhythmias that could cause sudden death. Eight percent of asymptomatic individuals will have an arrythymogenic episode within 3 years.19 Patients identified as having Brugada syndrome are at high risk of SCD and require extensive cardiac testing and treatment prior to any potential participation in athletics.
Screening The preparticipation physical exam (PPE) is a widespread mechanism used to detect athletes for illnesses or injuries that may predispose them to further problems in athletic participation. Most states in the United States require a PPE prior to high school sports participation, and participation in NCAA sports requires a PPE. A primary objective of the PPE is to detect underlying cardiovascular pathology that could predispose the athlete to SCD.20 Preparticipation cardiovascular screening in the PPE should include a combination of 5 personal history questions, 3 family history questions, and 4 physical exam findings as endorsed by the American Heart Association (AHA).21 Any positive findings of these parts of the PPE may prompt the examiner toward further cardiac workup prior to sports participation. The National Federation of State High Schools has left regulation regarding the PPE to individual states and there is no mandate or universal standard in the United States. Studies have shown increased compliance with the AHA recommendations but only 80% of states have been found to adequately screen for cardiovascular disease using the AHA recommendation.22 Effectiveness of the PPE for detecting underlying cardiovascular disease is a topic of debate. A case series showed the ability of the PPE to recognize a cardiac cause of SCD was 0.9%.5 SCD may occur without prior symptoms or family history in up to 80% of cases.23 The PPE is performed at considerable cost considering its low sensitivity and specificity for detecting underlying cardiac disorders. The estimated effectiveness of the PPE at preventing causes of SCD is determined to be about $119 000 per life year saved.24 Despite this weakness in detection of cardiac abnormalities, the benefit of the PPE goes beyond its ability to detect SCD in its scope to help identify and prevent other problems that can causes significant morbidity in sport and in its capacity to recognize and prevent injury. It also provides a conduit for adolescents to be seen for well medical care since 50% of adolescents visit a doctor’s office only for a PPE.25 Use of EKG for screening as part of the PPE has generated significant debate. The AHA recommends against use of the EKG for screening, but it is endorsed by the International Olympic Committee (IOC) and the European College of Cardiology (ECC).21 The IOC and the ECC use data from the Italian screening program that has shown a large decrease in the incidence of SCD after the implementation of a national screening program that includes EKG.4 Instituting a national EKG screening in the United States would come at a great cost, and the prevalence of SCD in the general population is small, thus decreasing the effectiveness of screening. It is estimated that the cost would be double that of
210 the Italian program. There have been a number of studies that have shown an increased prevalence of underlying cardiac disease that can lead to SCD in different cohorts of athletes such as NCAA athletes and military recruits. EKG is very sensitive but not specific. A 15% false positive rate with EKG screening has been quoted, but there has been an update in the criteria for EKG abnormalities that would require further cardiac workup. By not including EKGs with isolated voltage criteria for left ventricular hypertrophy, the expected false positive rate would drop to 2% to 4%.26 When evaluating the cost-effectiveness of EKG screening compared to PPE alone, there does seem to be benefit. PPE alone costs $199 000 per life year saved whereas adding EKG decreases this to $41 000 per life year saved.24 This does take into account the cost of testing for false positives. Echocardiography is a costly test and is very time consuming. Some studies have shown that using a limited 2D Echo is a feasible modality to add to the PPE.27 A limited Echo could be performed and interpreted within approximately 5 minutes when performed by a cardiovascular specialist. Cost is estimated anywhere from $35 to $400 per echocardiogram.27 A recent study showed that Echo is able to identify conditions not noted on EKG, such as bicuspid aortic valves (bAV), atrial septal defects (ASD), and mitral valve prolapse (MVP) in the asymptomatic patient.28 Out of 3100 male soccer players, there were 56 abnormal echocardiograms. Two of these were significant for HCM but the EKGs were also abnormal, which would have prompted ordering an echocardiogram prior to participation. The majority of athletes with the other conditions (bAV, MVP, and ASD) are able to participate in sports without restriction.29 Adding Echo will allow physicians to find more pathology but it is unlikely to significantly affect SCD in the young athlete. The specificity and sensitivity of the EKG with the lower false positive rate is a better option if any cardiovascular screening test is to be added to the PPE. It is unlikely that Echo has any role as a national screening test for the PPE. Its role is currently most valuable in the setting of those athletes with symptoms, concerning history, or abnormal EKG.
Conclusions Sudden cardiac death in the young athlete is a devastating phenomenon. A variety of congenital conditions relating to the heart are responsible. The PPE is one step in the process of trying to identify these problems. Incorporating the AHA recommendations into the PPE is an important first step but this lacks effectiveness. Taking a critical look at the prevalence of underlying
Clinical Pediatrics 54(3) cardiovascular disease in the young athlete will help us understand if more advanced modalities such as electrocardiogram and echocardiogram should be instituted in certain populations. Even with good evidence, the logistics of adding more resources toward the PPE for all young athletes would be burdensome with regard to time and finances. Appropriate screening of the young athlete for causes of sudden cardiac death in the United States continues to evolve as European models are analyzed and guidelines are changed. Declaration of Conflicting Interests The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author received no financial support for the research, authorship, and/or publication of this article.
References 1. Maron BJ, Doerer JJ, Haas TS, Tierney DM, Mueller FO. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. Circulation. 2009;119:1085-1092. 2. Eckart RE, Scoville SL, Campbell CL, et al. Sudden death in young adults: a 25-year review of autopsies in military recruits. Ann Intern Med. 2004;141:829-834. 3. Harmon KG, Asif IM, Klossner D, Drezner JA. Incidence of sudden cardiac death in national collegiate athletic association athletes. Circulation. 2011;123:1594-1600. 4. Corrado D, Basso C, Pavei A, Michieli P, Schiavon M, Thiene G. Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program. JAMA. 2006;296:1593-1601. 5. Maron BJ, Shirani J, Poliac LC, Mathenge R, Roberts WC, Mueller FO. Sudden death in young competitive athletes. Clinical, demographic, and pathological profiles. JAMA. 1996;276:199-204. 6. Maron BJ. Hypertrophic cardiomyopathy: a systematic review. JAMA. 2002;287:1308-1320. 7. Maron BJ, Anan TJ, Roberts WC. Quantitative analysis of the distribution of cardiac muscle cell disorganization in the left ventricular wall of patients with hypertrophic cardiomyopathy. Circulation. 1981;63:882-894. 8. Maron BJ, Olivotto I, Spirito P, et al. Epidemiology of hypertrophic cardiomyopathy-related death: revisited in a large non-referral-based patient population. Circulation. 2000;102:858-864. 9. Corrado D, Basso C, Schiavon M, Thiene G. Screening for hypertrophic cardiomyopathy in young athletes. N Engl J Med. 1998;339:364-369. 10. Corrado D, Thiene G, Nava A, Rossi L, Pennelli N. Sudden death in young competitive athletes: clinicopathologic correlations in 22 cases. Am J Med. 1990;89:588-596.
Womack 11. Thiene G, Nava A, Corrado D, Rossi L, Pennelli N. Right ventricular cardiomyopathy and sudden death in young people. N Engl J Med. 1988;318:129-133. 12. Peters S, Trummel M, Meyners W. Prevalence of right ventricular dysplasia-cardiomyopathy in a non-referral hospital. Int J Cardiol. 2004;97:499-501. 13. Basso C, Corrado D, Marcus FI, Nava A, Thiene G. Arrhythmogenic right ventricular cardiomyopathy. Lancet. 2009;373:1289-1300. 14. Cheitlin MD, De Castro CM, McAllister HA. Sudden death as a complication of anomalous left coronary origin from the anterior sinus of Valsalva, a not-so-minor congenital anomaly. Circulation. 1974;50:780-787. 15. Basso C, Maron BJ, Corrado D, Thiene G. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol. 2000;35:1493-1501. 16. Wellens HJ, Rodriguez LM, Timmermans C, Smeets JP. The asymptomatic patient with the Wolff-ParkinsonWhite electrocardiogram. Pacing Clin Electrophysiol. 1997;20(8 pt 2):2082-2086. 17. Goldenberg I, Zareba W, Moss AJ. Long QT syndrome. Curr Probl Cardiol. 2008;33:629-694. 18. Priori SG, Schwartz PJ, Napolitano C, et al. Risk stratification in the long-QT syndrome. N Engl J Med. 2003;348:1866-1874. 19. Brugada J, Brugada R, Antzelevitch C, Towbin J, Nademanee K, Brugada P. Long-term follow-up of individuals with the electrocardiographic pattern of right bundle-branch block and ST-segment elevation in precordial leads V1 to V3. Circulation. 2002;105:73-78. 20. American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine. Preparticipation Physical Evaluation. 4th ed. Washington, DC: American Academy of Pediatrics; 2010.
211 21. Maron BJ, Thompson PD, Ackerman MJ, et al. Recommendations and considerations related to preparticipation screening for cardiovascular abnormalities in competitive athletes: 2007 update: a scientific statement from the American Heart Association Council on Nutrition, Physical Activity, and Metabolism: endorsed by the American College of Cardiology Foundation. Circulation. 2007;115:1643-1455. 22. Glover D, Maron B. Abstract 2441: Evolution over 8 years of the US preparticipation screening process for unsuspected cardivascular disease in US high school athletes. Circulation. 2006;114:II-502. 23. de Noronha SV, Sharma S, Papadakis M, Desai S, Whyte G, Sheppard MN. Aetiology of sudden cardiac death in athletes in the United Kingdom: a pathological study. Heart. 2009;95:1409-1414. 24. Wheeler MT, Heidenreich PA, Froelicher VF, Hlatky MA, Ashley EA. Cost-effectiveness of preparticipation screening for prevention of sudden cardiac death in young athletes. Ann Intern Med. 2010;152:276-286. 25. Stevens MB, Smith GN. The preparticipation sports assessment. Fam Pract Recert. 1986;8(3):68-88. 26. Uberoi A, Stein R, Perez MV, et al. Interpretation of the electrocardiogram of young athletes. Circulation. 2011;124:746-757. 27. Wyman RA, Chiu RY, Rahko PS. The 5-minute screening echocardiogram for athletes. J Am Soc Echocardiogr. 2008;21:786-788. 28. Rizzo M, Spataro A, Cecchetelli C, Quaranta F, Livrieri S, Sperandii F, Cifra B, Borrione P, Pigozzi F. Structural cardiac disease diagnosed by echocardiography in asymptomatic young male soccer players: implications for pre-participation screening. Br J Sports Med. 2012 Apr;46(5):371-3. 29. Maron BJ, Zipes DP. Introduction: eligibility recom mendations for competitive athletes with cardiovascular abnormalities-general considerations. J Am Coll Cardiol. 2005;45:1318-1321.
2014
CPJXXX10.1177/0009922814527507WomackClinical Pediatrics
Commentary
Proper Screening for Sudden Cardiac Death in the Young Athlete
Clinical Pediatrics 2015, Vol. 54(3) 208–211 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/0009922814527507 cpj.sagepub.com
Jason Womack, MD1 Sudden cardiac death (SCD) in the young athlete is a devastating event. It often occurs without warning and is the most common cause of death in the athlete under 40 years of age.1 There is much debate on the best practice in which to detect athletes at risk for SCD. A cardiac health history incorporated into a preparticipation physical exam is widely accepted but its effectiveness is limited. Use of more advanced cardiac studies such as electrocardiogram and echocardiogram is highly debated.
Epidemiology Death from exertion is an unfortunate risk associated with physical activity. The etiologies of these incidents are related to heat illness, trauma, and underlying medical conditions. Cardiovascular disease is the leading cause of sudden death in the young athlete. The incidence of SCD is quoted to be 1/160 000 in the general population of the United States.1 There is debate to the validity of this number as most reports are from media outlets as there is no national or international reporting system. Studies of smaller cohorts of patients have yielded higher incidences of SCD. A study of military recruits showed an incidence of 1/9000,2 and a study of NCAA athletes showed an incidence of 1/44 000.3 A study of SCD in the Veneto region of Italy yielded an incidence of 1/28 000.4 In the athlete 40 years of age or older, coronary artery disease is the leading cause of SCD. Under the age of 40, structural or electrical abnormalities of the cardiovascular system that have gone undiagnosed are the leading cause of SCD.
Structural Causes of SCD Ideally, physicians would have an effective way to discover silent etiologies that put an athlete at risk for a cardiac event. Unfortunately, the ability to detect some of the most common forms of SCD in the athlete is very limited. The majority of these problems can present with SCD as their first symptom. SCD can be caused by a number of intrinsic and extrinsic factors. The most common cause of SCD in the United States is hypertrophic cardiomyopathy (HCM).5
It has a prevalence of 1 in 500 adults. Despite this, it is unlikely to present itself clinically in the majority of cases.6 It is inherited genetically in an autosomal dominant fashion and has variable penetrance. The morphology of HCM is that of a hypertrophied left ventricle in the absence of associated cardiac or systemic disease. Patients with HCM may or may not present with a heart murmur depending on the degree of left ventricular outflow obstruction.6 Electrocardiogram (EKG) is often abnormal in HCM, and echocardiogram shows characteristic left ventricular wall enlargement.6 The histological appearance of HCM is that of a disordered cellular architecture.7 Sudden death due to arrhythmia from HCM is the most likely symptomatic manifestation to occur in children and young adults and suspected to be increased in the presence of mild exertion.8,9 Arrythmogenic right ventricular cardiomyopathy (ARVC) is another congenital heart abnormality that leads to SCD in the young athlete. A study of sudden death in the Veneto region of Italy determined there was a relatively high prevalence of this disorder in its population.10,11 Its prevalence is 1:1000 to 1:5000 in the general population and is inherited in an autosomal dominant pattern.12,13 In ARVC there is a congenital abnormality in the histological make up of the right ventricular that leads to a replacement of the normal cardiovascular myocytes with fibrofatty tissue. This disorganization leads to interruption of normal electrical impulses that can become the nidus for conduction abnormalities.13 Another cause of SCD in the young athlete is from congenital coronary artery anomalies. Episodic cardiac ischemia, infarction, or both is thought to occur in the setting of an anomalous coronary artery.14 There are many mechanisms that are hypothesized for an anomalous coronary artery to lead to cardiac ischemia, but most episodes of SCD seem to occur in patients with an anomalous left main coronary artery and occur during 1
Rutgers University Robert Wood Johnson Medical School, New Brunswick, NJ, USA Corresponding Author: Jason Womack, Department of Family Medicine and Community Health, Robert Wood Johnson Medical School, Rutgers University, 1 RWJ Pl, MEB 2nd Fl, New Brunswick, NJ 08903, USA. Email: [email protected]
209
Womack physical activity.15 Although difficult to detect clinically, surgical intervention can correct the problems of anomalous coronary arteries. Marfans syndrome is a genetic disease of connective tissue that leads to an error in the body’s production of fibrillin. Fibrillin is important in the integrity of connective tissues. The cardiovascular system is one of the many organ systems affected by the lack of fibrillin, particular the integrity of blood vessel walls. The aortic arch is at risk for dilation that can ultimately lead to aneurysm and rupture. Exercise puts a greater stress on the aorta and increases the risk of this catastrophic event.
Electrical Abnormalities There are many conditions that primarily expose people to a variety of arrhythmias without any structural abnormalities of the heart. There are different mechanisms that may predispose these people to have arrhythmia. It is often difficult to identify patients with this predisposition as they have not had time to declare symptoms or initial symptoms could result in death. Wolf–Parkinson–White syndrome is characterized by a preexcitation pathway connecting the atria and the ventricles. Under normal conditions, the ventricles are protected by the refractory period of the AV node. In the presence of an accessory pathway, the ventricles can be exposed to high atrial rates that could cause the ventricles to degenerate into a lethal arrhythmia.16 This is particularly problematic in people with supraventricular arrhythmias such as atrial fibrillation. Long QT syndrome is a genetic disorder that leads to prolonged repolarization of the ventricles of the heart. It has an incidence in the general population of about 1:3000 to 1:5000 and is inherited in an autosomal dominant pattern. The underlying disturbance is within the ion channels responsible for repolarization of the heart. This disturbance can lead the heart into ventricular arrhythmias and SCD.17 Approximately 13% of patients with untreated Long QT will go on to SCD.18 Brugada syndrome is a pattern of cardiac electrocardiographic activity represented by right bundle branch block and ST segment elevation in the right precordial leads. Patients with this disorder have a large incidence of having arrhythmias that could cause sudden death. Eight percent of asymptomatic individuals will have an arrythymogenic episode within 3 years.19 Patients identified as having Brugada syndrome are at high risk of SCD and require extensive cardiac testing and treatment prior to any potential participation in athletics.
Screening The preparticipation physical exam (PPE) is a widespread mechanism used to detect athletes for illnesses or injuries that may predispose them to further problems in athletic participation. Most states in the United States require a PPE prior to high school sports participation, and participation in NCAA sports requires a PPE. A primary objective of the PPE is to detect underlying cardiovascular pathology that could predispose the athlete to SCD.20 Preparticipation cardiovascular screening in the PPE should include a combination of 5 personal history questions, 3 family history questions, and 4 physical exam findings as endorsed by the American Heart Association (AHA).21 Any positive findings of these parts of the PPE may prompt the examiner toward further cardiac workup prior to sports participation. The National Federation of State High Schools has left regulation regarding the PPE to individual states and there is no mandate or universal standard in the United States. Studies have shown increased compliance with the AHA recommendations but only 80% of states have been found to adequately screen for cardiovascular disease using the AHA recommendation.22 Effectiveness of the PPE for detecting underlying cardiovascular disease is a topic of debate. A case series showed the ability of the PPE to recognize a cardiac cause of SCD was 0.9%.5 SCD may occur without prior symptoms or family history in up to 80% of cases.23 The PPE is performed at considerable cost considering its low sensitivity and specificity for detecting underlying cardiac disorders. The estimated effectiveness of the PPE at preventing causes of SCD is determined to be about $119 000 per life year saved.24 Despite this weakness in detection of cardiac abnormalities, the benefit of the PPE goes beyond its ability to detect SCD in its scope to help identify and prevent other problems that can causes significant morbidity in sport and in its capacity to recognize and prevent injury. It also provides a conduit for adolescents to be seen for well medical care since 50% of adolescents visit a doctor’s office only for a PPE.25 Use of EKG for screening as part of the PPE has generated significant debate. The AHA recommends against use of the EKG for screening, but it is endorsed by the International Olympic Committee (IOC) and the European College of Cardiology (ECC).21 The IOC and the ECC use data from the Italian screening program that has shown a large decrease in the incidence of SCD after the implementation of a national screening program that includes EKG.4 Instituting a national EKG screening in the United States would come at a great cost, and the prevalence of SCD in the general population is small, thus decreasing the effectiveness of screening. It is estimated that the cost would be double that of
210 the Italian program. There have been a number of studies that have shown an increased prevalence of underlying cardiac disease that can lead to SCD in different cohorts of athletes such as NCAA athletes and military recruits. EKG is very sensitive but not specific. A 15% false positive rate with EKG screening has been quoted, but there has been an update in the criteria for EKG abnormalities that would require further cardiac workup. By not including EKGs with isolated voltage criteria for left ventricular hypertrophy, the expected false positive rate would drop to 2% to 4%.26 When evaluating the cost-effectiveness of EKG screening compared to PPE alone, there does seem to be benefit. PPE alone costs $199 000 per life year saved whereas adding EKG decreases this to $41 000 per life year saved.24 This does take into account the cost of testing for false positives. Echocardiography is a costly test and is very time consuming. Some studies have shown that using a limited 2D Echo is a feasible modality to add to the PPE.27 A limited Echo could be performed and interpreted within approximately 5 minutes when performed by a cardiovascular specialist. Cost is estimated anywhere from $35 to $400 per echocardiogram.27 A recent study showed that Echo is able to identify conditions not noted on EKG, such as bicuspid aortic valves (bAV), atrial septal defects (ASD), and mitral valve prolapse (MVP) in the asymptomatic patient.28 Out of 3100 male soccer players, there were 56 abnormal echocardiograms. Two of these were significant for HCM but the EKGs were also abnormal, which would have prompted ordering an echocardiogram prior to participation. The majority of athletes with the other conditions (bAV, MVP, and ASD) are able to participate in sports without restriction.29 Adding Echo will allow physicians to find more pathology but it is unlikely to significantly affect SCD in the young athlete. The specificity and sensitivity of the EKG with the lower false positive rate is a better option if any cardiovascular screening test is to be added to the PPE. It is unlikely that Echo has any role as a national screening test for the PPE. Its role is currently most valuable in the setting of those athletes with symptoms, concerning history, or abnormal EKG.
Conclusions Sudden cardiac death in the young athlete is a devastating phenomenon. A variety of congenital conditions relating to the heart are responsible. The PPE is one step in the process of trying to identify these problems. Incorporating the AHA recommendations into the PPE is an important first step but this lacks effectiveness. Taking a critical look at the prevalence of underlying
Clinical Pediatrics 54(3) cardiovascular disease in the young athlete will help us understand if more advanced modalities such as electrocardiogram and echocardiogram should be instituted in certain populations. Even with good evidence, the logistics of adding more resources toward the PPE for all young athletes would be burdensome with regard to time and finances. Appropriate screening of the young athlete for causes of sudden cardiac death in the United States continues to evolve as European models are analyzed and guidelines are changed. Declaration of Conflicting Interests The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author received no financial support for the research, authorship, and/or publication of this article.
References 1. Maron BJ, Doerer JJ, Haas TS, Tierney DM, Mueller FO. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. Circulation. 2009;119:1085-1092. 2. Eckart RE, Scoville SL, Campbell CL, et al. Sudden death in young adults: a 25-year review of autopsies in military recruits. Ann Intern Med. 2004;141:829-834. 3. Harmon KG, Asif IM, Klossner D, Drezner JA. Incidence of sudden cardiac death in national collegiate athletic association athletes. Circulation. 2011;123:1594-1600. 4. Corrado D, Basso C, Pavei A, Michieli P, Schiavon M, Thiene G. Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program. JAMA. 2006;296:1593-1601. 5. Maron BJ, Shirani J, Poliac LC, Mathenge R, Roberts WC, Mueller FO. Sudden death in young competitive athletes. Clinical, demographic, and pathological profiles. JAMA. 1996;276:199-204. 6. Maron BJ. Hypertrophic cardiomyopathy: a systematic review. JAMA. 2002;287:1308-1320. 7. Maron BJ, Anan TJ, Roberts WC. Quantitative analysis of the distribution of cardiac muscle cell disorganization in the left ventricular wall of patients with hypertrophic cardiomyopathy. Circulation. 1981;63:882-894. 8. Maron BJ, Olivotto I, Spirito P, et al. Epidemiology of hypertrophic cardiomyopathy-related death: revisited in a large non-referral-based patient population. Circulation. 2000;102:858-864. 9. Corrado D, Basso C, Schiavon M, Thiene G. Screening for hypertrophic cardiomyopathy in young athletes. N Engl J Med. 1998;339:364-369. 10. Corrado D, Thiene G, Nava A, Rossi L, Pennelli N. Sudden death in young competitive athletes: clinicopathologic correlations in 22 cases. Am J Med. 1990;89:588-596.
Womack 11. Thiene G, Nava A, Corrado D, Rossi L, Pennelli N. Right ventricular cardiomyopathy and sudden death in young people. N Engl J Med. 1988;318:129-133. 12. Peters S, Trummel M, Meyners W. Prevalence of right ventricular dysplasia-cardiomyopathy in a non-referral hospital. Int J Cardiol. 2004;97:499-501. 13. Basso C, Corrado D, Marcus FI, Nava A, Thiene G. Arrhythmogenic right ventricular cardiomyopathy. Lancet. 2009;373:1289-1300. 14. Cheitlin MD, De Castro CM, McAllister HA. Sudden death as a complication of anomalous left coronary origin from the anterior sinus of Valsalva, a not-so-minor congenital anomaly. Circulation. 1974;50:780-787. 15. Basso C, Maron BJ, Corrado D, Thiene G. Clinical profile of congenital coronary artery anomalies with origin from the wrong aortic sinus leading to sudden death in young competitive athletes. J Am Coll Cardiol. 2000;35:1493-1501. 16. Wellens HJ, Rodriguez LM, Timmermans C, Smeets JP. The asymptomatic patient with the Wolff-ParkinsonWhite electrocardiogram. Pacing Clin Electrophysiol. 1997;20(8 pt 2):2082-2086. 17. Goldenberg I, Zareba W, Moss AJ. Long QT syndrome. Curr Probl Cardiol. 2008;33:629-694. 18. Priori SG, Schwartz PJ, Napolitano C, et al. Risk stratification in the long-QT syndrome. N Engl J Med. 2003;348:1866-1874. 19. Brugada J, Brugada R, Antzelevitch C, Towbin J, Nademanee K, Brugada P. Long-term follow-up of individuals with the electrocardiographic pattern of right bundle-branch block and ST-segment elevation in precordial leads V1 to V3. Circulation. 2002;105:73-78. 20. American Academy of Family Physicians, American Academy of Pediatrics, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine. Preparticipation Physical Evaluation. 4th ed. Washington, DC: American Academy of Pediatrics; 2010.
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