What views and measurements are obtained from a screening echocardiogram (echo) to evaluate sudden cardiac arrest (SCA) risk in young adults or athletes?

Screening Echocardiography for SCA Risk Assessment in Young Adults and Athletes

Screening echocardiography for sudden cardiac arrest (SCA) risk assessment in young adults and athletes should include specific views and measurements targeting structural heart conditions that may cause SCD, though it should be performed only after abnormal findings on initial screening with history, physical examination, and ECG.

Standard Views and Measurements in Screening Echocardiography

When echocardiography is indicated based on abnormal initial screening, the following views and measurements are typically obtained:

Left Ventricle Assessment

• Parasternal long-axis view: Measures interventricular septal thickness, posterior wall thickness, and left ventricular cavity dimensions 1, 2
• Parasternal short-axis views: Evaluates for asymmetric septal hypertrophy and other regional wall abnormalities
• Apical 4-chamber view: Assesses left ventricular size, function, and regional wall motion
• Left ventricular mass calculation: To identify hypertrophic cardiomyopathy (HCM)
• Systolic function measurements: Ejection fraction and fractional shortening

Right Ventricle Assessment

• RV size and function: To identify arrhythmogenic right ventricular cardiomyopathy (ARVC)
• RV wall thickness: To detect RV hypertrophy

Valvular Assessment

• Mitral valve morphology: To identify mitral valve prolapse
• Aortic valve morphology: To detect bicuspid aortic valve

Great Vessels

• Aortic root dimensions: To identify aortic dilation
• Coronary artery origins: When visible, to detect anomalous coronary arteries

Additional Measurements

• Atrial dimensions: To assess for atrial enlargement
• Doppler studies: To evaluate for diastolic dysfunction and valvular abnormalities
• Tissue Doppler imaging: For myocardial function assessment

Effectiveness and False Positive Rates

The effectiveness of screening echocardiography remains controversial:

• Detection rate: A study of 2,898 collegiate athletes found that focused 5-minute screening echocardiograms identified 3 athletes (0.1%) with serious cardiac abnormalities warranting sports restriction that were not detected by history and physical examination 3

• False positive concerns: Echocardiography can detect physiological adaptations in athletes ("athlete's heart") that may mimic pathological conditions, leading to unnecessary additional testing and sports restriction 2

• Cost-effectiveness: The European Society of Cardiology guidelines note that echocardiography is not recommended as a first-line screening tool due to cost considerations but should be used when initial screening (history, physical examination, and ECG) raises concerns 1

• Current recommendations: The American Heart Association and American College of Cardiology recommend echocardiography only after abnormal findings on history, physical examination, or ECG, rather than as a universal screening tool 1

Targeted Screening Approach

The American Academy of Pediatrics recommends a targeted approach to screening:

1. Initial screening with 4 key questions focused on:

   • History of fainting/seizures during exercise
   • Exercise-related chest pain or shortness of breath
   • Family history of sudden death before age 50
   • Family history of specific cardiac conditions 1

2. Physical examination and 12-lead ECG for those with positive responses 1

3. Echocardiography only when indicated by abnormal findings in steps 1 and 2 1

Emerging Recommendations

Some experts now advocate for at least two screening echocardiograms during an athlete's career 2:

• First during adolescence to detect congenital abnormalities
• Second at age 30-35 to evaluate for pathological cardiac remodeling and late-onset cardiomyopathies

Common Pitfalls and Caveats

• Overdiagnosis: Distinguishing physiological adaptations from pathological conditions requires expertise in sports cardiology
• Underdiagnosis: Some conditions like coronary artery anomalies and CPVT may not be detected by echocardiography
• Limited sensitivity: Echocardiography alone cannot detect electrical abnormalities like Long QT syndrome or Brugada syndrome
• Resource limitations: Universal echocardiographic screening would require significant healthcare resources and specialized interpretation

Conclusion for Clinical Practice

While echocardiography is a valuable tool for detecting structural heart conditions associated with SCA/SCD, its use as a universal screening tool is not currently recommended by major cardiovascular societies. Instead, a stepwise approach starting with history, physical examination, and ECG, with selective use of echocardiography for those with abnormal findings, represents the most evidence-based approach to screening young adults and athletes for SCA risk.