• Etiology
    • Physiologic adaptation to training (Endurance → Eccentric; Resistance → Concentric).
    • ↑ Vagal tone, ↓ Sympathetic tone.
  • Clinical Features
    • Asymptomatic.
    • Sinus Bradycardia (< 50 bpm).
    • S3 and Systolic ejection murmur are common/normal.
  • Diagnostics
    • ECG: Sinus bradycardia, LVH voltage criteria, 1st degree AV block.
    • Echo: Symmetric wall thickening (< 15mm), Normal diastolic function, Dilated LV cavity.
  • Ddx: Athlete’s vs. Hypertrophic Cardiomyopathy (HCM)
    • Morphology: Athlete’s = Symmetric; HCM = Asymmetric septal hypertrophy.
    • Cavity Size: Athlete’s = Dilated; HCM = Small.
    • Deconditioning Trial: Cessation of training results in regression of LVH in Athlete’s heart (unchanged in HCM).
  • Management
    • Reassurance (benign). No restrictions.