Table 2.

Respiratory and hemodynamic responses to loading and unloading at rest

	Healthy					HFREF
	S	L1	L2	UL1	UL2	S	L1	L2	UL1	UL2
Peak inspiratory ITP (cmH₂O)	−3.7 ± 1.6 ^* ^†	−5.3 ± 1.5	−9.9 ± 6.4	−0.5 ± 4.2	1.2 ± 3.8	−3.7 ± 2.0 ^* ^†	−4.9 ± 1.9	−7.5 ± 1.8	−1.0 ± 1.7	2.3 ± 2.3
Peak expiratory ITP (cmH₂O)	2.1 ± 3.7 ^*	1.9 ± 3.4	2.0 ± 3.4	3.6 ± 2.9	3.3 ± 2.6	3.6 ± 2.0 ^*	3.6 ± 2.2	3.7 ± 2.1	4.1 ± 1.9	4.2 ± 2.5
Pdi (cmH₂O)	6.7 ± 5.3 ^* ^†	8.3 ± 5.0	12.8 ± 9.9	1.9 ± 6.2	0.1 ± 6.0	5.5 ± 5.1 ^* ^†	6.6 ± 4.71	9.2 ± 4.9	2.9 ± 6.2	−0.7 ± 6.0
Tidal volume (L)	1.33 ± 0.30 ^*	1.39 ± 0.30	1.44 ± 0.33	1.64 ± 0.65	1.73 ± 0.77	1.29 ± 0.12 ^*	1.39 ± 0.19	1.40 ± 0.30	1.79 ± 0.54	1.74 ± 0.74
RR (breath/min)	14.9 ± 3.3 ^* ^†	14.3 ± 4.1	11.6 ± 5.4	14.8 ± 5.8	17.1 ± 7.0	15.1 ± 4.1 ^* ^†	12.9 ± 3.6	12.6 ± 4.6	15.1 ± 4.8	7.5 ± 5.1
MAP (mmHg)	100 ± 11 ^†	101 ± 11	103 ± 12	99 ± 12	100 ± 12	78 ± 11 ^†	79 ± 12	80 ± 12	76 ± 8	76 ± 7
SVR (dyn·s/cm⁵)	1409 ± 342	1414 ± 346	1395 ± 360	1434 ± 301	1406 ± 359	930 ± 350	920 ± 352	900 ± 383	926 ± 363	935 ± 358

main effect for unloading,

^†

main effect for loading, HFREF: Heart failure and reduced ejection fraction, ITP: intrathoracic pressure, Pdi: transdiaphragmatic pressure, RR: respiratory rate, MAP: mean arterial pressure, SVR: systemic vascular resistance