Characteristics | Athletes | Non-athletes | % Difference |
PR interval (ms) | 148 (142–154)* (10; 5671) (98%) | 139 (136–141) (4; 737) (41%) | 6.1 |
QRS duration (ms) | 86 (84–88) (11; 6938) (97%) | 83 (79–86) (6; 952) (97%) | 4 |
QTc duration (ms) | 396 (391–400) (11; 7018) (97%) | 386 (375–398) (6; 902) (97%) | 3 |
QRS axis* (°) | 70 (63.1–76.1) (8; 5476) (99%) | 70 (67.9–73.0) (4; 779) (60%) | 0 |
Group 1 ECG patterns | OR | ||
Sinus bradycardia (%) | 37.4 (17.6–59.7)† (11; 9745) (99%) | 19.2 (16.6 21.90) (3; 834) (0%) | 2.5 (2.1–3.0) |
Sinus arrhythmia (%) | 45.8 (35.7–56.0) (3; 2898) (95.9%) | ||
First-degree AV block (%) | 2.2 (0.8–4.2)† (8; 9488) (97%) | 0.4 (0.1–1.1) (3; 834) (26%) | 4.6 (1.7–12.4) |
Second-degree AV block (Morbitz type I) (%) | 0.2 (0.1–0.4) (3; 2898) (0%) | ||
Incomplete RBBB (%) | 25.8 (18.2–33.7)† (10; 9736) (97%) | 7.8 (4.2–12.4) (3; 834) (78%) | 4.3 (3.5–5.6) |
LVH (%) | 35.2 (26.0–45.0)† (11; 9745) (98%) | 24.1 (20.3–28.1) (3; 834) (41%) | 1.7 (1.5–2.0) |
ER (%) | 37.1 (25.6–49.2)† (10; 9736) (99.3%) | 29.2 (17.2–43.0) (3; 834) (93.9%) | 1.4 (1.2–1.7) |
Group 2 ECG patterns | Risk ratio | ||
TWI (≥1 mm) (%) | 6.7 (4.7–8.9) (7; 9372) (93.3%) | 5.9 (2.2–11.2) (3; 834) (86.7%) | 1.1 (0.8–1.5) |
Deep TWI (≥2 mm) (%) | 4.7 (2.3–8.1)† (7; 6514) (95.9%) | 0.3 (0.04–1.8) (2; 534) (60.3%) | 12.7 (3.1–50.7) |
Anterior (%) | 6.5 (2.9–11.3) (7; 9372) (98.4%) | 5.7 (2.2–10.6) (3; 834) (84.9%) | 1.2 (0.9–1.5) |
Extended anterior (%) | 1.4 (0.2–3.5) (4; 5391) (95.8%) | 0.9 (0.2–2.2) (2; 534) (24.1%) | 1.5 (0.6–3.6) |
Inferior (%) | 1.0 (0.3–2) (5; 7446) (93%) | 0.0 (3; 834) | NC |
Lateral (%) | 0.3 (0.05–0.6) (5; 7446) (80%) | 0.0 (3; 834) | NC |
Inferolateral (%) | 2.0 (1.0–3.3) (8; 9256) (93%) | 0.0 (3; 834) | NC |
ST segment depression (%) | 0.03 (0.003–0.08) (6; 7615) (0%) | 0.0 (3; 834) | NC |
Abnormal Q waves (%) | 0.1 (0.03–0.2) (10; 9902) (25%) | 0.0 (3; 834) | NC |
LAE (%) | 3.5 (0.4–9.5) (8; 5804) (98%) | ||
RAE (%) | 5.9 (0.9–14.8) (4; 2575) (98%) | ||
LAD (%) | 0.4 (0.1–0.9) (6; 5683) (75%) | ||
RAD (%) | 3.7 (0.1–11.8) (5; 4352) (98%) | ||
RVH (%) | 9.8 (7.0–13.0) (3; 2420) (81%) | ||
Ventricular pre-excitation (%) | 0.6 (0.2–1.1) (6; 7422) (79%) | ||
Complete RBBB (%) | 0.5 (0.3–0.7) (8; 9715) (55%) | 0.0 (3; 834) | NC |
Complete LBBB (%) | 0.1 (0.008–0.3) (7; 9499) (81%) | 0.0 (3; 834) | NC |
Long QT interval (%) | 0.6 (0.1–1.3) (9; 10247) (57%) | 0.0 (3; 834) | NC |
Short QT interval (%) | 0.4 (0.02–1.1) (4; 4108) (81%) | 0.0 (3; 834) | NC |
Brugada-like ER (%) | 0.2 (0.03–0.4) (5; 7079) (0%) |
Data are presented as mean or percentage (95% CI) (number of articles; number of participants) (heterogeneity).
*p≤0.05, significantly greater or more prevalent in athletes than non-athletes.
† p≤0.001, significantly greater or more prevalent in athletes than non-athletes.
AV, atrioventricular; anterior, V1–V3; ER, early repolarisation; extended anterior, V1–V4; inferior, leads II-aVF; inferolateral, leads II-aVF/V4-V6/I-aVL; lateral: V4-V6/I-aVL; LAE, left atrial enlargement; LAD, left axis deviation; LVH, left ventricular hypertrophy; NC, non-computable; RAD, right axis deviation; LBBB, left bundle branch block; RAE, right atrial enlargement; RBBB, right bundle branch block; TWI, T-wave inversion.