. Author manuscript; available in PMC: 2016 Sep 9.

Published in final edited form as: Am J Physiol Regul Integr Comp Physiol. 2010 Apr 21;299(1):R80–R91. doi: 10.1152/ajpregu.00246.2009

Table 1.

Cardiorespiratory, MSNA, and HRV responses during 5 min of SB and CB at rest

Breathing Condition	P_{ET_CO₂}, mmHg	V_T, liters	RR, breaths/min	V̇_E, l/min	HR, beats/min	MAP, mmHg	MSNA		HRV
Breathing Condition	P_{ET_CO₂}, mmHg	V_T, liters	RR, breaths/min	V̇_E, l/min	HR, beats/min	MAP, mmHg	Burst Incidence, burts/100 heartbeats	Total Activity, arbitrary units	LF, ms²	HF, ms²	HF, nu	LF/HF
SB	44.2 (3.8)	0.78 (0.19)	12.5 (3.4)	8.8 (2.1)	62 (9)	86 (9)	19.7 (4.9)	24.1 (11.1)	3,420 (2,229)	2,835 (1,995)	43.6 (20.2)	2.0 (2.1)
CB	45.2 (3.8)	0.80 (0.14)	20.3 (0.4)^†	16.1 (2.9)^†	63 (9)	89 (8)^*	18.8 (6.6)	25.5 (13.5)	1,327 (1,193)^*	2,375 (1,974)	55.6 (17.6)	0.80 (0.86)

Values are means (SD); (n = 12). Responses were measured during spontaneous (SB) and controlled breathing (CB) at rest. P_{ET_CO₂}, end-tidal CO₂ partial pressure; VT, tidal volume; RR, respiratory rate; V̇_E, minute ventilation; HR, heart rate; MAP, mean arterial pressure; MSNA, muscle sympathetic nerve activity; HRV, heart rate variability [ms², absolute power of low- (LF) or high-frequency (HF) HRV; nu, normalized units].

P < 0.05;

^†

P < 0.01, significantly different from SB condition.