Correlation Between Hemodynamic Characterizations of Cervical Arteries and Changes in Cerebral Microcirculation Under Dobutamine Stress: A Self- Controlled Study

Background Dobutamine, an inotropic agent, is known to enhance cardiac function. However, its concurrent effects on cervical artery hemodynamics and cerebral microcirculation, along with their potential correlation, remain unclear. This study aimed to investigate these relationships in healthy volunteers under dobutamine stress. Methods In this self-controlled study, vessel diameters, peak systolic velocity, end-diastolic velocity (EDV), mean flow velocity (MV), resistance index and pulsatility index of cervical arteries paramerers of 20 healthy volunteers were obtained via ultrasound. Whole cerebral blood flow (wCBF_ASL) and CBF_ROI were obtained by magnetic resonance imaging using arterial spin labeling before and during dobutamine stress tests. Blood flows (BF) of cervical arteries were calculated from the MV and the vessel diameter. Cerebral blood flow (CBF_US) is the total BF of the left and right internal carotid artery (ICA) and vertebrobasilar artery. Results Overall cerebral blood flow, measured by both CBF_US and wCBF_ASL, remained unchanged during dobutamine stress (P > 0.05). However, dobutamine induced significant reductions in CBF_ROI in specific regions, including the right middle temporal pole, left middle temporal pole, and left cerebellum (P < 0.05). Notably, changes in the MV of the right internal carotid artery (ICA-R) were positively correlated with CBF_ROI changes in the right middle temporal pole, whereas changes in EDV showed a negative correlation (P < 0.05). Conlusions Dobutamine administration can induce regional cerebral hypoperfusion despite stable global cerebral blood flow. Changes in cervical artery hemodynamic parameters, particularly in the internal carotid artery, are correlated with these regional perfusion deficits. Therefore, monitoring cervical artery dynamics may be crucial for identifying patients at risk of localized cerebral ischemia during dobutamine stress tests.