ECG characteristics of paediatric athletes: impact of age
| Characteristics | ≥14 years | <14 years | % Difference |
| PR interval (ms) | 151 (140–162) (4; 1985) (99%) | 142 (137–147) (4; 89) (58%) | 6 |
| QRS duration (ms) | 92 (91–93)* (4; 1991) (59%) | 74 (70–82) (3; 77) (88%) | 9 |
| QTc duration (ms) | 377 (354–400) (5; 4205) (99%) | 394 (375–412) (3; 77) (6%) | −5 |
| QRS axis* (°) | 76 (73–78) (4; 2816) (89%) | 74.7 (61.4–88.0) (2; 63) (75%) | 2 |
| Group 1 ECG patterns | OR | ||
| Sinus bradycardia (%) | 61.3 (46.3–75.3)
†
(5; 4205) (98%) | 18.8 (12.1–26.7) (2; 109) (0%) | 6.6 (4.1–10.7) |
| LVH (%) | 48.0 (36.4–59.5)
†
(5; 4205) (98%) | 20.7 (9.3–35.1) (2; 109) (30%) | 3.4 (2.2–5.5) |
| Group 2 ECG patterns | Risk ratio | ||
| TWI (≥1 mm) (%) | 6.9 (3.7–10.9)
†
(6; 5051) (96%) | 5.4 (0.2–16.9) (2; 1272) (92%) | 1.3 (1.0–1.7) |
| Anterior (%) | 5.4 (1.4–11.8) (7; 6575) (98%) | 6.7 (4.4–9.4)‡ (3; 2516) (78%) | 1.2 (1.0–1.5) |
| Extended anterior (%) | 1.7 (0.4–4.0)* (4; 3823) (94%) | 0.5 (0.1–3.0) (2; 1257) (68%) | 3.1 (1.4–6.6) |
| Inferolateral (%) | 2.5 (1.0–4.6)† (5; 3710) (89%) | 0.1 (0.01–0.4) (2; 1272) (0%) | 15.8 (3.9–63.9) |
Data are presented as mean or percentage (95% CI) (number of articles; number of participants) (heterogeneity).
*p≤0.01, significantly greater or more prevalent in athletes≥14 years than in athletes <14 years.
† p≤0.001, significantly greater or more prevalent in athletes≥14 years than in athletes <14 years.
‡ ≤0.05, significantly greater or more prevalent in athletes<14 years than in athletes ≥14 years.
Anterior: V1–V3; extended anterior: V1–V4; inferolateral: leads II-aVF/V4-V6/I-aVL; NC, non-computable; LVH, left ventricular hypertrophy; TWI, T-wave inversion.