. 2011 May 2;301(1):H173–H179. doi: 10.1152/ajpheart.01211.2010

Table 2.

Ventilatory and cardiovascular measures for peripheral and central chemoreflex sensitivity in HUT70

	Central Chemoreflex				Peripheral Chemoreflex
	Eucapneic normoxia		Hyperoxic hypercapnia		Eucapneic hyperoxia		Eucapneic hypoxia
HUT70	Controls	POTS	Controls	POTS	Controls	POTS	Controls	POTS
Arterial oxygen saturation, %	97.5 ± 0.6	97.2 ± 0.2	99.2 ± 0.6	98.9 ± 0.2	98.9 ± 0.6	98.7 ± 0.6	80.8 ± 2.3^*	84.7 ± 1.4^*^†
Minute ventilation, l/min	4.6 ± 8.8	8.8 ± 1.2^†	26.8 ± 3.3^*	13.6 ± 2.3^*^†	6.5 ± 0.4	10.1 ± 1.9	7.6 ± 1.1^*	11.1 ± 0.9^*^†
Respiratory rate, beats/min	16.7 ± 1.1	18.6 ± 1.4	21.4 ± 1.2^*	17.6 ± 1.9	14.3 ± 1.4	14.9 ± 1.2	13.5 ± 0.6	15.5 ± 0.9
ETCO₂, Torr	41.2 ± 1.2	34.4 ± 1.8^†	60.2 ± 1.7^*	55.1 ± 2.5^*	42.6 ± 1.6	42.9 ± 1.6	40.1 ± 1.4	41.3 ± 2.3
Heart rate, beats/min	82.8 ± 3.9	101.5 ± 5.4^†^‡	84.9 ± 4.2	100.9 ± 4.5	76.8 ± 4.9	94.5 ± 6.5	85.9 ± 4.2	102.9 ± 4.5^†^‡
Systolic arterial pressure, mmHg	118.8 ± 3.9	114.1 ± 2.5	141.4 ± 10.9^*	133.6 ± 3.9^*	115.3 ± 7.1	120.2 ± 4.5	119.5 ± 5.2	121.8 ± 3.6
Diastolic arterial pressure, mmHg	67.3 ± 3.8	64.3 ± 2.5	73.5 ± 4.5^*	73.4 ± 2.7^*	62.7 ± 3.8	64.2 ± 2.6	66.8 ± 2.6	70.5 ± 3.1
Mean arterial pressure, mmHg	86.2 ± 3.4	81.8 ± 2.4	99.5 ± 6.4^*	94.7 ± 2.9^*	82.6 ± 5.3	88.9 ± 3.3	85.3 ± 3.1	89.2 ± 3.1
Cardiac output, l/min	4.3 ± 0.3.1	4.9 ± 0.3	6.2 ± 0.3^*	5.5 ± 0.3	4.9 ± 0.3	4.3 ± 0.4	5.1 ± 0.5	4.9 ± 0.4
TPR, mmHg·l⁻¹·min⁻¹	21.1 ± 1.4	17.9 ± 1.3^‡	16.7 ± 1.3	17.9 ± 1.7	18.3 ± 2.1	23.1 ± 2.4^‡	17.6 ± 1.6	20.4 ± 1.9
Stroke volume, ml	52.1 ± 4.1^‡	57.1 ± 3.1	74.1 ± 3.1^*	57.1 ± 5.1	63.1 ± 7.1^‡	47.1 ± 06^‡	63.1 ± 7.1^*	47.1 ± 4.1^‡

Values are means ± SE. HUT70, head-up tilt at 70° position.

P < 0.05 compared with eucapneic normoxia;

^†

P < 0.05 compared with controls;

^‡

compared with supine (Table 1).