Computational and Mathematical Methods in Medicine

Research Article

Assessment of Baroreflex Sensitivity Using Time-Frequency Analysis during Postural Change and Hypercapnia

Table 3

Physiological parameters and baroreflex sensitivity estimates during postural change between squatting and standing in hypercapnia with hypoxia.


Parameter	Cycle 1			Cycle 2
Parameter	Squatting	Standing	Value	Squatting	Standing	Value

EtCO₂ (mm Hg)	47 (43–49)	47 (43–48)	ns	48 (45–51)	48 (45–51)	ns
RR (breaths/min)	11 (9–14)	13 (10–15)	ns	12 (11–16)	14 (11–17)	ns
MAP (mm Hg)	108 (95–118)	106 (95–119)	ns	112 (101–123)	106 (97–119)	0.008
PP (mm Hg)	75 (66–83)	82 (72–93)	<10⁻⁴	77 (68–89)	81 (73–94)	0.006
HR (bmp)	83 (73–88)	81 (71–88)	ns	78 (63–87)	79 (72–91)	0.02
LF BRS (ms/mm Hg)	9.7 (5.4–14.2)	7.9 (6.2–11.6)	ns	7.7 (5.6–13.4)	7.8 (5.1–14.7)	ns
HF BRS (ms/mm Hg)	8.9 (5.4–13.7)	7.1 (5.4–8.8)	0.006	13.4 (7.9–19.4)	7.5 (6.0–9.9)	0.002

Values are presented as median (first quartile–third quartile). EtCO₂: mean end-tidal carbon dioxide level, RR: mean respiration rate, MAP: mean arterial blood pressure, PP: pulse pressure, HR: heart rate, LF BRS: baroreflex sensitivity in low-frequency range, HF BRS: baroreflex sensitivity in high-frequency range, and ns: difference not statistically significant.