The Effect of Dobutamine without and with L‐Arginine on Arterial Compliance in Heart Failure Patients

Abstract

The effect of dobutamine on carotid and brachial arteries compliance and the association of L-arginine as a potential nitric oxide pathway restorer were evaluated in patients with heart failure. Twenty-seven outpatients participated. Drugs used for the treatment of heart failure were withheld at least 24 hours before the study. The carotid and brachial artery diameters and hemodynamic variables were evaluated by ultrasonography and Doppler in baseline conditions, with dobutamine, with flow-mediated dilatation (FMD), and with placebo or L-arginine alone and associated with dobutamine. There was a significant increase in carotid peak blood flow with dobutamine when compared with that at baseline (P = 0.0001) or with L-arginine or placebo (P = 0.0001 and P = 0.0001, respectively), with increase of the cardiac index (P = 0.0001). Dobutamine did not increase carotid arterial compliance. FMD significantly increased the brachial peak blood flow (P = 0.0022) and the artery diameter (P = 0.0001). Dobutamine did not change the brachial artery diameter. Brachial peak blood flow was increased with dobutamine alone or associated with placebo or L-arginine comparing with L-arginine or placebo alone (P = 0.0168 and P = 0.0140, respectively), but was not increased compared with that at baseline. L-arginine infusion was not associated with changes in carotid, brachial, or in the cardiac index. We concluded that dobutamine increased carotid peak blood flow in patients with heart failure, although without changing the arterial compliance. The FMD of brachial artery was maintained, while brachial artery response to dobutamine infusion was less reliable. The carotid artery may be under the direct influence of the heart, while the brachial artery may be under predominant local control.