22. Pediatric Sports Cardiology and Athlete ECG Screening
Pre-participation cardiovascular screening in young athletes aims to identify structural and electrical substrates capable of precipitating Exercise-Induced Sudden Cardiac Arrest (SCA).
1. International Consensus Criteria for Pediatric Athlete ECGs
| Normal Training-Related Findings (Physiological "Athlete's Heart") | Abnormal ECG Findings Requiring Comprehensive Cardiovascular Workup |
|---|---|
| 1. Increased QRS voltage for LVH (isolated voltage criteria without strain). | 1. T-Wave Inversions: $\ge 1\text{ mm}$ deep in $\ge 2$ contiguous leads (excluding $V_1-V_3$ in children $<16$ yr). |
| 2. Incomplete Right Bundle Branch Block (IRBBB). | 2. ST-Segment Depression: $\ge 0.5\text{ mm}$ in $\ge 2$ contiguous leads. |
| 3. Early Repolarization Pattern (J-point elevation with concave ST elevation). | 3. Pathological Q Waves: Depth $>3-4\text{ mm}$ or duration $\ge 40\text{ ms}$ in $\ge 2$ leads. |
| 4. Sinus Bradycardia (resting HR $\ge 30-40\text{ bpm}$) & Sinus Arrhythmia. | 4. Complete Left Bundle Branch Block (LBBB) or IVCD $\ge 140\text{ ms}$. |
| 5. First-Degree AV Block & Mobitz Type I Wenckebach during rest/sleep. | 5. Ventricular Pre-Excitation (short PR + delta wave). |
| 6. Juvenile T-Wave Inversions in $V_1 - V_3$ in athletes $<16$ years of age. | 6. Prolonged $QTc$: $\ge 470\text{ ms}$ (males) or $\ge 480\text{ ms}$ (females); Short $QTc < 330\text{ ms}$. |
| 7. Type 1 Brugada Pattern & Epsilon Waves. |
2. Commotio Cordis
- Mechanism: Sudden blunt, non-penetrating mechanical impact to the precordium directly over the heart during the vulnerable $15-30\text{ ms}$ window on the upslope of the T wave (Phase 3 repolarization).
- Outcome: Immediate induction of Ventricular Fibrillation (VF) without structural cardiac damage.
- Emergency Resuscitation: Immediate CPR and Automated External Defibrillator (AED) shock within $<3\text{ minutes}$ achieves survival rates $>70\%$.