Heart rate, RR, QT, and QTc intervals, and QT, QTc, and RR dispersion parameters for normal boys and girls
| Boys ( n = 200 ) mean age 12.3 (2.1) years | Girls ( n = 172 ) mean age 12.5 (2.3) years | p | Whole group ( n = 372 ) mean age 12.4 (2.6) years | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean (SD) | 95th Centile | Mean (SD) | 95th Centile | Mean (SD) | 95th Centile | ||||||
| HR (beats/min) | 89.1 (13.7) | 114 | 89.7 (13.3) | 115 | 0.66 | 89.4 (13.6) | 114 | ||||
| Mean RR (ms) | 680.3 (116.1) | 896.1 | 671.9 (104.3) | 838.6 | 0.47 | 676.9 (111.4) | 877.7 | ||||
| Mean QT (ms) | 324.3 (22.6) | 360.9 | 328.4 (26.1) | 366.1 | 0.10 | 325.9 (24.1) | 363.7 | ||||
| Mean QTc (ms) | 396.1 (20.2) | 432.2 | 402.6 (18.2) | 432.8 | 0.001 | 398.7 (19.7) | 432.4 | ||||
| QT max (ms) | 339.2 (23.2) | 380 | 343.4 (27.7) | 390 | 0.11 | 340.8 (25.2) | 380 | ||||
| QTc max (ms) | 420.7 (23.4) | 453.5 | 425.8 (18.8) | 462 | 0.026 | 422.7 (21.8) | 457.6 | ||||
| QTD (ms) | 29.8 (9.8) | 50 | 30.0 (10.9) | 50 | 0.90 | 29.9 (10.2) | 50 | ||||
| QTcD (ms) | 47.9 (16.9) | 80.4 | 46.5 (16.2) | 75 | 0.42 | 47.3 (16.6) | 79.7 | ||||
| QT-SD (ms) | 9.7 (3.1) | 15.5 | 10.0 (3.3) | 16.3 | 0.41 | 9.8 (3.2) | 15.6 | ||||
| QTc-SD (ms) | 15.5 (5.6) | 27.0 | 15.4 (5.5) | 26.4 | 0.93 | 15.5 (5.5) | 26.9 | ||||
| RRD (ms) | 96.9 (70.3) | 274 | 89.8 (64.4) | 320 | 0.32 | 94.1 (68.0) | 250 | ||||
| RR-SD (ms) | 39.8 (29.4) | 107.4 | 36.8 (26.5) | 93.7 | 0.31 | 38.6 (28.3) | 101.5 | ||||
HR, heart rate.