. 2017 Sep 15;313(6):H1155–H1161. doi: 10.1152/ajpheart.00287.2017

Table 1.

Cardiorespiratory and cerebrovascular variables at baseline and during both low (5 μg·kg⁻¹·min⁻¹) and high doses (15 μg·kg⁻¹·min⁻¹) of dobutamine

	Baseline		Low Dose		High Dose
	Value	n	Value	n	Value	n	PValue
Hemodynamics
HR, beats/min	62.000 ± 11.000		64.000 ± 12.000		95.000 ± 20.000^*^†		<0.001
SBP, mmHg	116.000 ± 9.000		141.000 ± 14.000^*		182.000 ± 22.000^*^†		<0.001
DBP, mmHg	65.000 ± 7.000		65.000 ± 6.000		60.000 ± 5.000		0.105
MAP, mmHg	82.000 ± 6.000		91.000 ± 6.000^*		101.000 ± 8.000^*^†		<0.001
CO, l/min	6.800 ± 1.900		8.500 ± 1.800^*		10.000 ± 1.400^*^†		<0.001
$P E T_{C O_{2}}$ , mmHg	48.300 ± 2.700		44.400 ± 3.800^*		43.600 ± 2.400^*^†		<0.001
TVC, l·min⁻¹·mmHg⁻¹	0.082 ± 0.017		0.095 ± 0.021^*		0.099 ± 0.011^*
Cerebral blood flow
ICA
Blood flow, ml/min	317.000 ± 61.000		290.000 ± 50.000^*		300.000 ± 51.000^*		0.002
Diameter, cm	0.490 ± 0.050		0.480 ± 0.000		0.480 ± 0.050		0.299
Velocity, cm/s	28.000 ± 5.000		27.000 ± 6.000		28.000 ± 6.000		0.804
Conductance, ml·min⁻¹·mmHg⁻¹	3.850 ± 0.630		3.200 ± 0.480^*		2.970 ± 0.340^*^†		<0.001
ECA
Blood flow, ml/min	115.000 ± 39.000		137.000 ± 45.000^*		179.000 ± 61.000^*^†		<0.001
Diameter, cm	0.380 ± 0.070		0.380 ± 0.070		0.400 ± 0.070^*^†		0.008
Velocity, cm/s	16.000 ± 3.000		19.000 ± 3.000^*		23.000 ± 6.000^*^†		<0.001
Conductance, ml·min⁻¹·mmHg⁻¹	1.390 ± 0.550		1.480 ± 0.540		1.720 ± 0.620^*^†		0.009
CCA
Blood flow, ml/min	471.000 ± 113.000		460.000 ± 104.000		470.000 ± 102.000		0.694
Diameter, cm	0.590 ± 0.070		0.600 ± 0.080		0.570 ± 0.070		0.123
Velocity, cm/s	29.000 ± 5.000		27.000 ± 5.000		31.000 ± 7.000^†		0.039
Conductance, ml·min⁻¹·mmHg⁻¹	5.770 ± 1.030	12	5.010 ± 0.890^*	10	4.730 ± 0.940^*	8	0.007
Calculated CCA
Blood flow, ml/min	429.000 ± 74.000		423.000 ± 69.000		475.000 ± 194.000^*^†		<0.001
Conductance, ml·min⁻¹·mmHg⁻¹	5.250 ± 0.880		4.680 ± 0.730^*		4.690 ± 0.750^*		0.003
Cardiac function
EDV, ml	104.000 ± 34.000		111.000 ± 34.000		100.000 ± 43.000		0.634
ESV, ml	39.000 ± 15.000		26.000 ± 8.000^*		20.000 ± 12.000^*		<0.001
EF, %	63.000 ± 4.000	10	76.000 ± 6.000^*	10	82.000 ± 6.000^*^†	9	<0.001
S′(s), cm/s	8.100 ± 0.700	11	11.700 ± 1.700^*	11	16.600 ± 3.700^*^†	11	<0.001
S′(l), cm/s	11.000 ± 1.400	11	15.700 ± 2.400^*	11	21.400 ± 4.600^*^†	11	<0.001

Data are means ± SD; n = 12 (if the number of subjects lacked, the actual number of subjects is shown at each measurement value). HR, heart rate; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; CO, cardiac output; $P E T_{C O_{2}}$ , end-tidal carbon dioxide pressure; TVC, total vascular conductance; ICA, internal carotid artery; ECA, external carotid artery; CCA, common carotid artery; calculated CCA, value obtained by summing measured ICA and ECA blood flows; EDV, left ventricular end-diastolic volume ; ESV, left ventricular end-systolic volume; EF, ejection fraction; S′(s), peak septal mitral annular tissue systolic velocity; S′(l), peak lateral mitral annular tissue systolic velocity.

Different from baseline (P < 0.05);

^†

different from the low dose of dobutamine (P < 0.05).