Sudden Cardiac Death in Young Athletes: Practical Challenges and Diagnostic Dilemmas
The following are 10 points to remember from this state-of-the-art paper pertaining to sudden cardiac death (SCD) in young athletes:
1. Cross-sectional studies in the United States have demonstrated incidence rates of 2.3-4.4/100,000 per year for SCD in young athletes.
2. In athletes older than 35 years of age, 80% of SCD is due to atherosclerotic coronary artery disease.
3. The reported prevalence of hypertrophic cardiomyopathy (HCM) is 0.2% in the general population and 0.07%-0.08% in athletes. More than 90% of affected individuals have an abnormal resting electrocardiogram (ECG). Common ECG findings include T-wave inversion, pathological Q waves, ST-depression in >2 contiguous leads, and left bundle branch block.
4. Congenital coronary anomalies are an important cause of SCD in young patients, causing SCD in 12%-33% of athletes. Surgical intervention is almost always recommended for anomalous left coronary from the right sinus, while the management of anomalous right coronary artery from the left sinus is controversial. Exercise stress testing is poorly predictive for SCD in patients with congenital coronary anomalies.
5. Other potential causes of SCD with characteristic ECG findings include arrhythmogenic right ventricular cardiomyopathy (ARVC) and Brugada syndrome. The ECG in ARVC may demonstrate T-wave inversion in the right precordial leads. The type 1 ECG pattern in Brugada syndrome demonstrates partial right bundle branch block and downsloping ST-segment elevation in leads V1-V4.
6. In patients with Wolf-Parkinson-White syndrome, determining the electrical properties of the accessory pathway is important in establishing the risk of SCD. For this reason, referral to an electrophysiologist is recommended.
7. In the United States, the incidence of SCD in athletes due to long QT syndrome is 2%. Long QT syndrome should be considered when the QTc interval exceeds 440 ms in males or 460 ms in females. As athletes may exhibit slightly longer QT intervals as compared with the general population, restriction of athletes is recommended for males with a QTc exceeding 470 ms and females with a QTc exceeding 480 ms.
8. Myocarditis is not uncommon as a cause of SCD, accounting for up to 7% of SCD in young athletes.
9. It is important to distinguish between the athlete’s heart and HCM. Although the majority of individuals with HCM have a mean left ventricular wall thickness of 18-20 mm or greater, a male athlete with a wall thickness of 13-15 mm falls into a ‘grey zone.’ Diagnostic clues from HCM include symptoms, family history, ECG abnormalities (other than isolated voltage criteria for left ventricular hypertrophy), asymmetrical septal hypertrophy, peak VO2 <50 ml/kg/min, left atrial enlargement, and delayed enhancement on cardiac magnetic resonance imaging.
10. Preparticipation screening may play an important role in the identification of athletes at risk for SCD. While a screening protocol assessing symptoms, family history, and physical examination is nearly uniformly recommended, the use of ECG screening is controversial. ECG screening of athletes is recommended by the European Society of Cardiology, but not by the American Heart Association.
Clinical Topics: Arrhythmias and Clinical EP, Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Sports and Exercise Cardiology, Atherosclerotic Disease (CAD/PAD), EP Basic Science, Genetic Arrhythmic Conditions, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Congenital Heart Disease, CHD & Pediatrics and Arrhythmias, CHD & Pediatrics and Imaging, CHD & Pediatrics and Quality Improvement, Acute Heart Failure, Magnetic Resonance Imaging, Sports & Exercise and Congenital Heart Disease & Pediatric Cardiology, Sports & Exercise and Imaging
Keywords: Arrhythmogenic Right Ventricular Dysplasia, Brugada Syndrome, Athletes, Coronary Artery Disease, Wolff-Parkinson-White Syndrome, Cross-Sectional Studies, Cardiomyopathy, Hypertrophic, Long QT Syndrome, Heart Failure, Myocarditis, Magnetic Resonance Imaging, Death, Sudden, Cardiac
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