. Author manuscript; available in PMC: 2014 Mar 12.

Published in final edited form as: Eur Respir J. 2011 Oct 27;39(6):1449–1457. doi: 10.1183/09031936.00125011

TABLE 2.

Timing and pattern of breathing during graded exercise in patients with heart failure (HF) and control subjects

	V′_E 20 L·min⁻¹		V′_E 40 L·min⁻¹		V′_E 60 L·min⁻¹		V′_E 80 L·min⁻¹
	Control	HF	Control	HF	Control	HF	Control	HF
V_T L	1.07±0.04	1.03±0.06	1.73±0.05	1.59±0.07^*	2.27±0.05	2.02±0.11^*	2.63±0.10	2.19±0.16^*
f_R breaths·min⁻¹	20.8±0.9	21.9±1.2	23.4±0.7	25.5±1^*	27.0±0.9	30.0±1.4^*	30.8±1.3	34.9±1.9^*
t_I s	1.27±0.08	1.12±0.08	1.20±0.06	1.03±0.05^*	1.06±0.05	0.90±0.06^*	0.94±0.05	0.79±0.05^*
t_E s	1.75±0.09	1.76±0.13	1.42±0.03	1.39±0.06	1.21±0.03	1.15±0.04	1.04±0.04	0.90±0.06^*
t_I/t_tot	0.42±0.01	0.40±0.01	0.46±0.01	0.43±0.01^*	0.47±0.01	0.44±0.01^*	0.47±0.01	0.47±0.01
V_T/t_I L·s⁻¹	0.85±0.03	0.93±0.03	1.46±0.04	1.54±0.03	2.17±2.26	2.26±0.03	2.82±0.06	2.73±0.12
V_T/t_E L·s⁻¹	0.62±0.02	0.59±0.02	1.22±0.02	1.14±0.02^*	1.89±0.03	1.75±0.04^*	2.52±0.04	2.47±0.15

Data are presented as mean±SEM. V′_E: minute ventilation; V_T: tidal volume; f_R; respiratory frequency; t_I: inspiratory time; t_E: expiratory time; t_tot: total time of respiratory cycle.

p<0.05 compared with control group.