Fatal Family History Worries Young Man

ANSWER
The ECG shows normal sinus rhythm and left ventricular hypertrophy (LVH). LVH is indicated by high voltages in limb leads I and III (sum of R and S waves in leads I and III ≥ 25 mm) or in precordial leads V₁, V₅, and/or V₆ (sum of V₁ and either V₅ or V₆ ≥ 35 mm).

Subsequent work-up, including echocardiography and genetic testing, revealed a familial LVH.