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Case 011: Pre-Sports Physical with Abnormal ECG

Presentation

A 16-year-old male presents for pre-participation sports physical for varsity basketball. He denies any symptoms - no chest pain, syncope, palpitations, or dyspnea. He exercises regularly without limitation.

Family History: Grandfather died suddenly at age 45 - cause unknown. Father alive and well.

Physical Exam: Normal - no murmur at rest

ECG (obtained as part of screening): - Sinus rhythm, 62 bpm - LVH by voltage criteria - Deep T-wave inversions in V1-V4 and inferior leads - No delta wave

Clinical Reasoning

Question 1: Is this ECG normal for an athlete?

Answer **NO - This is ABNORMAL and requires further evaluation** **Normal athlete ECG adaptations:** - Sinus bradycardia - Voltage criteria for LVH alone - Early repolarization - Incomplete RBBB **ABNORMAL findings requiring workup:** - **T-wave inversions** (beyond V1-V2) - Pathologic Q waves - ST depression - QTc prolongation - Epsilon waves This athlete has deep T-wave inversions in V1-V4 and inferior leads - highly concerning for HCM.

Question 2: What is the differential diagnosis?

Answer **Concerning for cardiomyopathy:** 1. **Hypertrophic cardiomyopathy (HCM)** - most likely given pattern 2. **Arrhythmogenic cardiomyopathy (ACM/ARVC)** 3. **LV noncompaction** Family history of sudden death at 45 significantly increases concern. T-wave inversions in this distribution are NOT explained by athletic training.

Workup

Echocardiogram: - Asymmetric septal hypertrophy: 18mm (Z-score +4.5) - Normal LV cavity size - Normal systolic function (EF 65%) - No LVOT obstruction at rest - No SAM of mitral valve

Question 3: What is the diagnosis?

Answer **Hypertrophic Cardiomyopathy (HCM)** Diagnostic criteria met: - Wall thickness ≥15mm in adults (or Z-score ≥2 in children) - In absence of loading conditions explaining hypertrophy This patient: 18mm septal thickness with Z-score +4.5 confirms HCM.

Question 4: What additional testing is indicated?

Answer **Complete HCM evaluation:** 1. **Cardiac MRI** - Confirms extent of hypertrophy - Late gadolinium enhancement (LGE) = fibrosis = arrhythmia risk - Rules out phenocopies 2. **Holter monitor** - NSVT detection 3. **Exercise stress test** - Blood pressure response - Exercise-induced arrhythmias 4. **Genetic testing** - Confirms diagnosis - Family screening guidance - Prognostic information (some mutations higher risk) 5. **Family screening** - First-degree relatives need echo + ECG

Risk Stratification

Additional findings: - CMR: LGE present in septum (15% of LV mass) - Holter: No NSVT - Exercise test: Normal BP response, no arrhythmias - Family history: Sudden death at age 45 (unknown cause)

Question 5: What is his SCD risk?

Answer **Use HCM Risk-SCD Calculator or Pediatric HCM Risk Score (Norrish model)** **Risk factors present:** - Unexplained syncope: No - Family history SCD: Yes (grandfather) - NSVT: No - Maximal LV thickness: 18mm - LA diameter: Would need measurement - LVOT gradient: None - LGE on CMR: Yes (15%) **Norrish pediatric model factors:** - Unexplained syncope - NSVT - Maximal LV thickness Z-score - LA diameter Z-score - LVOT gradient Given family history + LGE, this patient warrants careful counseling about risk.

Question 6: Can he play basketball?

Answer **2025 Guidelines: Shared decision-making approach** Per current guidelines: - Previously: Blanket restriction from competitive sports - Now: **Shared decision-making** allowed for lower-risk patients **Discussion points:** - His individual risk factors - Family history is concerning - LGE present (associated with arrhythmia risk) - Would need comprehensive counseling - If participating: Ensure AED access, emergency plan **This patient has multiple concerning features:** - Family history of SCD - LGE on CMR Most experts would recommend **against competitive basketball** in this case, but final decision involves patient/family after full informed consent.

Management Plan

Question 7: What treatment should be initiated?

Answer **Medical therapy:** 1. **Beta-blocker** (metoprolol or atenolol) - First-line for symptoms - May reduce LVOT gradient (if develops) - Controversial for prevention in asymptomatic 2. **Avoid dehydration** - can worsen gradient 3. **Activity modification** - per shared decision-making discussion 4. **ICD consideration** - Would calculate 5-year risk score - If ≥6% 5-year risk: discuss ICD - If ≥4% with additional concerns: individualize 5. **Genetic testing and family screening** 6. **Avoid QT-prolonging drugs** (some HCM patients have associated channelopathy)

Teaching Points

  1. T-wave inversions beyond V1-V2 are ABNORMAL in athletes
  2. Family history of sudden death <50 always warrants evaluation
  3. HCM is the #1 cause of SCD in young athletes
  4. CMR with LGE helps risk stratify
  5. 2025: Shared decision-making replaces blanket restrictions
  6. First-degree relatives need screening (echo + ECG)