Table 2

Heart rate measures and frequency domain measures of heart rate variability by group

NormalAsthma
AirSO2AirSO2
Maximum heart rate beats·min−194.2 (89.8–98.6)96.6 (90.3–102.9)97.8 (91.5–104.3)94.0 (87.3–100.7)
Minimum heart rate beats·min−155.42 (52.1–58.7)53.3 (49.9–56.8)53.8 (50.5–57.2)54.8 (51.6–57.9)
Total power ms24825 (2461–7189)6555 (3188–9922)a3825 (2593–5057)2804 (2265–3343)
High frequency power ms21708 (518–2898)2672 (872–4472)1141 (407–1875)602 (333–871)
Low frequency power ms21401 (657–2145)1837 (806–2868)1502 (903–2101)930 (741–1119)
  • Data are presented as means (95% confidence interval). SO2: sulphur dioxide. a: p<0.05 by paired t-test, air versus SO2 in normal subjects.