Screening for Sudden Cardiac Death in Athletes and Low-Risk Patients Cameron Smith

Epidemiology The exact incidence of SCD in athletes remains unclear. Overall incidence is between 1:50,000 and 1:100,000 per year in young athletes 1 A total of 1866 athletes who died suddenly (or survived cardiac arrest), 19+/-6 years of age, were identified throughout the United States from 1980 to 2006 in 38 diverse sports 2

Epidemiology NCAA Data 2015

Most common cause of athlete death The majority of SCD events in athletes are due to malignant arrhythmias, usually sustained VT or VF. The most common cardiac causes were hypertrophic cardiomyopathy (36%) and congenital coronary artery anomalies (17%). 2 Other major causes include arrhythmogenic right ventricular cardiomyopathy (ARVC) especially in international populations. 3

Other causes of Cardiac death Recommendations and Considerations Related to Preparticipation Screening for Cardiovascular Abnormalities in Competitive Athletes: 2007 Update, Volume: 115, Issue: 12, Pages: 1643-1655, DOI: (10.1161/CIRCULATIONAHA.107.181423)

Other causes of Cardiac death 2003-2013 NCAA 6

Other causes of Cardiac death The most common anomaly associated with SCD is a coronary that courses between the aorta and pulmonary artery

Other causes of Cardiac death

Who should you screen with EKG? The USPSTF recommends against screening with resting or exercise ECG to prevent cardiovascular disease events in asymptomatic adults at low risk

Screening Algorithm

Who should you suspect? History of heart murmur 4 Exertional symptoms 4 Symptoms of Marfan Syndrome Family History of SCD Syncope Further evaluation should be considered for persons with heart or lung disease, bleeding disorders, musculoskeletal problems, history of concussion, or other neurologic disorders.

Who should you suspect? Upwards of approximately 30% of athletes with SCD have been reported to have had symptoms such as chest pain, shortness of breath, performance decline, palpitations, pre-syncope, or syncope leading up to the event

Hypertrophic Cardiomyopathy Autosomal Dominant Mutation in the Cardiac Sarcomere – β-Myosin Heavy Chain Prevalence is 1:500 in adults Histology shows disorganized pattern of hypertrophied myocytes in disarray with replacement fibrosis

Hypertrophic Cardiomyopathy Commonly asymptomatic Patients may report symptoms of DOE, SOB, orthopnea, PND, chest pain, palpitations, pre-syncope/syncope, fatigue, or edema Physical Exam Crescendo-Decrescendo Systolic Murmur best heart at apex and LLSB Murmur intensifies with Valsalva and standing Murmur decreases with handgrip, leg-lift, and squatting

Hypertrophic Cardiomyopathy ECG Findings 90% will have abnormal findings No pathognomonic signs Most often will show prominent abnormal Q waves, P wave abnormalities, left axis deviation, and deeply inverted T waves Echo Findings Increased LV wall thickness in the absence of another cause LVH (particularly asymmetrical LVH) Increased LVOT gradient Systolic anterior motion of the mitral valve leaflets

ECG is reproduced from Hansen & Merchant (2007). 

Hypertrophic Cardiomyopathy Diagnosis Using Echo/CMR – LV wall thickening >15mm anywhere in the LV without any other identifiable cause (HTN, AS, Athlete’s Heart) Suggest doing cardiovascular magnetic resonance in all patients with suspected or diagnosed HCM to most reliably assess LV morphology, including maximal LV wall thickness

Hypertrophic Cardiomyopathy Treatment and Prognosis Patients with symptoms of HF should be treated with Beta Blockers Non-dihydropyridine CCB (Verapamil/Diltiazem) Disopyramide Avoid vasodilators or diuretics, which may worsen LVOT obstruction Asymptomatic patients generally do not need Rx

References 1. Landry CH, Allan KS, Connelly KA, et al. Sudden Cardiac Arrest during Participation in Competitive Sports. N Engl J Med 2017; 377:1943. 2. 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 Mar 3;119(8):1085–92. 3. Wasfy MM, Hutter AM, Weiner RB. Sudden Cardiac Death in Athletes. Methodist Debakey Cardiovasc J. 2016 Apr-Jun;12(2):76-80. doi: 10.14797/mdcj-12-2-76. 4.https://www.aafp.org/afp/2015/0901/p371.html 5.https://www.aafp.org/afp/2018/0915/od1.html 6. Maron BJ, Douglas PS, Graham TP, Nishimura RA, Thompson PD. Task Force 1: preparticipation screening and diagnosis of cardiovascular disease in athletes. J Am Coll Cardiol. 2005 Apr 19;45(8):1322–6 7. Marijon E, Uy-Evanado A, Reinier K, Teodorescu C, Narayanan K, Jouven X, Gunson K, Jui J, Chugh SS Circulation. 2015 Apr 21; 131(16):1384-91. 8. Harmon KG, Asif IM, Maleszewski JJ et al. Incidence, Cause, and Comparative Frequency of Sudden Cardiac Death in National Collegiate Athletic Association Athletes: A Decade in Review. Circulation. 2015 Jul 7;132(1):10–9. 9. http://www.msdlatinamerica.com/ebooks/RadiologyReviewManual/sid990079.html 10. Maron M. Hypertrophic cardiomyopathy: Clinical manifestations, diagnosis, and evaluation. Up to Date. 2019 May 08. 11. Robinson A, Kramer C. Imaging in Hypertrophic Cardiomyopathy. American College of Cardiology. 2018 Apr 24. 12. http://www.msdlatinamerica.com/ebooks/RadiologyReviewManual/sid990079.html