Table 4.

Effect of low-dose dopamine infusion on normoxic, steady-state, systemic hemodynamics

	Saline	1 μg·kg−1·min−1	2 μg·kg−1·min−1	3 μg·kg−1·min−1	4 μg·kg−1·min−1	Effect of Dose
Heart rate (beat/min)
All	62 ± 2	62 ± 2	63 ± 2	64 ± 2	64 ± 2	0.150
High HVR	63 ± 3	63 ± 3	64 ± 3	65 ± 3	65 ± 3	0.505
Low HVR	61 ± 2	62 ± 2	62 ± 2	63 ± 2	64 ± 2	0.197
Mean blood pressure (mmHg)
All	96 ± 2	95 ± 2	93 ± 2	91 ± 1*†	93 ± 1	0.005
High HVR	94 ± 3	95 ± 2	93 ± 2	92 ± 2	93 ± 2	0.550
Low HVR	97 ± 2	94 ± 2	93 ± 2	90 ± 2*	92 ± 1	0.009
Total peripheral resistance [mmHg/(liters/min)]
All	15.3 ± 0.7	14.6 ± 0.6*	14.0 ± 0.5*†	13.8 ± 0.5*†	13.6 ± 0.7*†‡§	<0.001
High HVR	14.3 ± 1.1	14.2 ± 1.0	13.8 ± 1.8	13.2 ± 0.9	13.7 ± 1.0	0.376
Low HVR	16.0 ± 0.8	15.0 ± 0.7*	14.2 ± 0.6*	14.2 ± 0.5*	13.5 ± 0.4*†‡§	<0.001
Cardiac output (liters/min)
All	6.6 ± 0.2	6.7 ± 0.2	6.8 ± 0.2	6.8 ± 0.2	7.1 ± 0.2*†	0.006
High HVR	7.0 ± 0.4	7.0 ± 0.4	7.0 ± 0.4	7.3 ± 0.4	7.2 ± 0.4	0.459
Low HVR	6.3 ± 0.2	6.5 ± 0.2*	6.7 ± 0.1*	6.5 ± 0.2*	7.0 ± 0.2*†‡§	0.003
Stroke volume (ml)
All	113 ± 5	114 ± 4	112 ± 3	110 ± 3	114 ± 4	0.135
High HVR	122 ± 8	122 ± 7	116 ± 6	117 ± 5	120 ± 6	0.123
Low HVR	106 ± 5	107 ± 4	109 ± 4	105 ± 4	110 ± 4	0.072

Data reported as means ± SE, n = 30 unless otherwise noted (high n = 13, low n = 17).

^*P < 0.05 vs. saline,

^†P < 0.05 vs. 1 μg·kg⁻¹·min⁻¹,

^‡P < 0.05 vs. 2 μg·kg⁻¹·min⁻¹,

^§P < 0.05 vs. 3 μg·kg⁻¹·min⁻¹.

Numbers in bold represent statistical significance.