What is the diagnosis and management of athlete's heart (athletic heart syndrome)?

Diagnosis and Management of Athlete's Heart (Athletic Heart Syndrome)

Athlete's heart is a benign physiological adaptation to regular intense exercise that requires careful differentiation from pathological conditions but typically requires no specific treatment beyond appropriate monitoring and screening. 1

Diagnostic Features of Athlete's Heart

Clinical Presentation

• Often asymptomatic with incidental findings on routine examination
• Normal or enhanced exercise capacity
• Absence of cardiac symptoms (no exertional chest pain, syncope, or disproportionate dyspnea)
• Negative family history for sudden cardiac death or cardiomyopathies

Physical Examination Findings

• Sinus bradycardia (resting heart rate often 40-60 bpm)
• Regular rhythm with possible early repolarization
• Possible soft systolic murmur (flow murmur)
• Normal blood pressure or controlled hypertension

ECG Findings

• Sinus bradycardia
• First-degree AV block
• Early repolarization
• Voltage criteria for LV hypertrophy
• These training-related ECG changes should be distinguished from pathological findings such as:
  • ST-segment depression
  • T-wave inversion
  • Pathologic Q waves
  • Major conduction defects
  • Ventricular pre-excitation
  • Long/short QT interval 2

Echocardiographic Features

• Symmetric left ventricular hypertrophy (typically <12mm in Caucasians)
• Balanced chamber enlargement (all chambers proportionally enlarged)
• Normal or enhanced diastolic function
• LV cavity enlargement (end-diastolic diameter >54mm)
• Relative wall thickness between 0.30-0.45 2
• Normal global longitudinal strain 1

Differential Diagnosis Algorithm

Step 1: Initial Evaluation

• 12-lead ECG
• Detailed personal and family history
• Physical examination
• Echocardiography 1

Step 2: Gray Zone Evaluation (When Initial Findings Are Concerning)

For LV wall thickness in the gray zone (13-16mm):

• Findings favoring athlete's heart:

  • Enlarged LV cavity (>54mm)
  • Normal LV geometry
  • Normal diastolic function (septal e' velocity >8.0 cm/s)
  • Symmetric wall thickening (difference <2mm between segments)
  • Regression of hypertrophy after 3 months of detraining 2

• Findings favoring HCM:

  • Family history of sudden cardiac death/HCM
  • Major ECG abnormalities
  • Normal or reduced LV cavity size (<54mm)
  • Abnormal LV geometry or segmental hypertrophy
  • LV outflow tract obstruction
  • Abnormal diastolic function 2

Step 3: Advanced Imaging (When Diagnosis Remains Uncertain)

• Cardiac MRI with late gadolinium enhancement (LGE)
  • Absence of LGE favors athlete's heart
  • Presence of LGE suggests pathology 2
• Exercise echocardiography
  • Normal augmentation of systolic function with exercise favors athlete's heart
  • Absence of significant improvement (<15% increase in EF) suggests pathology 2

Right Ventricular Assessment

Distinguishing physiologic RV adaptation from arrhythmogenic cardiomyopathy (AC):

• Findings favoring athlete's heart:

  • Proportional enlargement of all chambers
  • Absence of regional wall motion abnormalities
  • Normal RV function (RVFAC >33%, RVEF >40%)
  • Normal RV function during exercise 2

• Findings favoring AC:

  • Family history of sudden cardiac death/AC
  • Anterior T-wave inversion on ECG
  • Ventricular arrhythmias with LBBB morphology
  • Regional wall motion abnormalities
  • Global RV dysfunction 2

Management Approach

For Confirmed Athlete's Heart

• No specific treatment required
• Continued participation in sports is permitted
• Regular cardiovascular screening as per athletic protocols

For Uncertain Diagnosis

• Consider temporary detraining (3 months)
  • Regression of LV hypertrophy suggests athlete's heart
  • Persistence suggests pathology 2
• Follow-up imaging studies annually
• Consider genetic testing if family history is positive

For Concerning Features

• Athletes with concerning features (exertional syncope, chest pain, arrhythmias) require comprehensive evaluation before clearance for sports 1
• Athletes with confirmed pathology (HCM, AC, coronary anomalies) should be managed according to disease-specific guidelines 1

Special Considerations

Ethnic Differences

• Black athletes exhibit more pronounced LV hypertrophy (up to 16mm) compared to white athletes (up to 15mm)
• Higher prevalence of ECG anomalies in black athletes (up to 40%)
• T-wave inversions in V1-V4 with ST-segment elevation may be normal variant in black athletes 2

Gender Differences

• Female athletes typically show less pronounced cardiac remodeling
• Upper limit of LV wall thickness is 11mm in white females and 13mm in black females 2

Monitoring Athletes in the Gray Zone

• Athletes with repolarization abnormalities without structural heart disease should undergo regular follow-up imaging
• Annual echocardiography is typically sufficient 2

Common Pitfalls to Avoid

1. Overdiagnosis of pathology in healthy athletes
2. Missing underlying pathology by attributing all findings to athletic adaptation
3. Failure to consider ethnic and gender differences in cardiac adaptation
4. Inadequate follow-up of borderline cases
5. Overlooking red flags such as exertional syncope, chest pain, or arrhythmias 1