Table 1

Demographic and clinical characteristics of athletes with or without TWI

CharacteristicsOverall
n=2261
Normal T waves n=2125TWI
n=136
p Value
Age, years, mean±SD112.4±2.6 (8–18)12.9±2.3 (8–18)11±3.5 (8–16)<0.0001
Age groups, n (%)
 8–10 years599 (26.5)524 (24.6)75 (55.1)<0.0001
 11–13 years857 (37.9)812 (38.2)45 (33.1)<0.0001
 14–16 years689 (30.5)675 (31.8)14 (10.3)<0.0001
 17–18 years116 (5.1)114 (5.4)2 (1.5)<0.0001
Male gender, n (%)2261 (100.0)2125 (100.0)136 (100.0)
Caucasian ethnicity, n (%)2261 (100.0)2125 (100.0)136 (100.0)
Height, cm, mean±SD157±16 (114–196)157.7±14.4 (114–196)149.2±25 (124–187)<0.0001
Weight, kg, mean±SD50±15 (20–100)51±14 (20–100)44.5±3.5 (24–90)<0.0001
Body surface area, m2, mean±SD1.5±0.3 (0.8–2.27)1.5±0.3 (0.8–2.27)1.35±0.4 (0.9–2.13)<0.0001
Body mass index, mean±SD1.6±0.2 (11.4–19.6)1.58±0.1 (11.4–19.6)1.49±3.5 (12.4–18.7)<0.0001
Systolic blood pressure, mm Hg, mean±SD110±11 (85–140)109.1±12.5 (85–140)103.7±22.3 (85–135)0.926
Diastolic blood pressure, mm Hg, mean±SD69±7 (50–90)67.8±8.9 (50–90)67.5±12.6 (50–85)0.617
Total training time, h/week, mean±SD7.3±1.7 (3–15)7.4±1.2 (3–15)7±1.1 (6–12)<0.0001
Medical history abnormalities, n (%)†26 (1.1)26 (100)0 (0)0.184
 Presyncope8 (0.4)8 (31)0 (0)
 Syncope7 (0.3)7 (27)0 (0)
 Palpitations5 (0.2)5 (19)0 (0)
 Exertional chest pain4 (0.2)4 (15)0 (0)
 Excessive exertional dyspnoea and fatigue2 (0.1)2 (8)0 (0)
Physical examination abnormalities, n (%)‡18 (0.8)15 (83)3 (17)0.886
 Heart murmurs ≥2/614 (0.6)12 (80)2 (67)
 Split second heart sound13 (0.6)13 (86)0 (0)
 Mid- or end-systolic clicks5 (0.2)5 (33)0 (0)
 Others§5 (0.2)4 (27)1 (33)
  • Data ranges are presented in parentheses.

  • †The sum of subpercentages is not equal to 1.1 because of approximations.

  • ‡More than one abnormality could be present in the same patient.

  • §Includes fourth sound (two cases), pectus excavatum (two cases) and reinforced second sound (one case).

  • TWI, T wave inversion.