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, cervical artery hemodynamic parameters, including vessel diameters, peak systolic velocity, end-diastolic velocity (EDV), mean flow velocity (MV), resistance index and pulsatility index of cervical arteries parameters of 20 healthy volunteers were obtained via ultrasound. Whole-brain cerebral blood flow (wCBF_ASL) and cerebral blood flow in regions of interest (CBF_ROI) were obtained by magnetic resonance imaging using arterial spin labeling before and during the dobutamine stress test. Blood flow (BF) in the cervical arteries were calculated from the MV and the vessel diameter. Ultrasound-derived cerebral blood flow (CBF_US) was defined as the sum of the BF from the left and right internal carotid arteries (ICA) and the 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, linear regression analysis revealed that the change in EDV of the right internal carotid artery (ICA-R) was a significant positive predictor of the CBF change in the right middle temporal pole (B = 0.32, p = 0.042).

CONCLUSIONS

Dobutamine administration can induce regional cerebral hypoperfusion despite stable global cerebral blood flow. Alterations in ICA hemodynamic parameters are correlated with these regional perfusion deficits. These findings suggest that monitoring cervical artery hemodynamics during dobutamine administration may offer insights into regional cerebral perfusion changes, and could potentially be explored as a complementary tool for risk stratification in patients undergoing dobutamine stress tests.