Table 4.
Hemodynamic responses to α-adrenergic antagonist (phentolamine) administration at rest
| BL | Prop (5 mg) | Phentolamine (2.25 mg) | |
|---|---|---|---|
| Control | |||
| Leg blood flow, ml/min | 234 ± 26 | 230 ± 27 | 477 ± 60# |
| Leg vascular conductance, ml·min−1·mmHg−1 | 2.7 ± 0.3 | 2.7 ± 0.3 | 5.7 ± 0.6# |
| Leg perfusion pressure, mmHg | 87 ± 3 | 86 ± 4 | 84 ± 4 |
| CFA diameter | |||
| cm | 1.02 ± 0.06 | 1.03 ± 0.05 | 1.05 ± 0.05 |
| %Δ | 1.1 ± 1.1 | 1.7 ± 1.2 | |
| HR, beats/min | 56 ± 3 | 54 ± 2 | 58 ± 3 |
| HFrEF | |||
| Leg blood flow, ml/min | 212 ± 24 | 557 ± 66# | |
| Leg vascular conductance, ml·min−1·mmHg−1 | 2.8 ± 0.3 | 7.4 ± 1.0*# | |
| Leg perfusion pressure, mmHg | 79 ± 4 | 77 ± 4 | |
| CFA diameter | |||
| cm | 0.88 ± 0.05 | 0.91 ± 0.06# | |
| %Δ | 4.1 ± 0.9*# | ||
| HR, beats/min | 67 ± 3* | 67 ± 3* |
Values are means ± SE. In controls, propranolol was administered immediately before phentolamine infusion (0.225 ml/min for 10 min) to minimize β-adrenergic effects. CFA, common femoral artery; HR, heart rate; HFrEF, heart failure with reduced ejection fraction.
*
P < 0.05 vs. control;
#
P < 0.05 vs. preinfusion.