Effect of dopamine on middle cerebral artery blood flow: A single case study

We present a single case study. on neurovascular dopamine effect in a patient with a circumscribed isolated hemodynamic relevant stenosis of the left intracranial internal carotid artery. After percutaneous transluminal angioplasty, angiography showed a restenosis and spasm. To improve cardiac output and to prevent hemodynamic reinfarction continously dopamine (4-7 μg/kg body weight/min) was infused. Transcranial Doppler sonography (TCD) of the affected left middle cerebral artery. (MCA) revealed a constant mean flow velocity (MFV) of 70 cm/sec despite hemodynamic changes due to dopamine. The Pulsatility Index (PI) was constantly low (0.4), suggesting a maximal vasodilation of the ipsilateral resistance vessels. In contrast, during dopamine infusion the MFV of the healthy right side increased from 42 cm/sec to 56 cm/sec and the PI decreased from 0.95 to 0.84. These recordings suggest that cerebral blood supply is augmented by dopamine infusion: firstly, due to an improved cardiac output and secondly, due to slight vasodilation of the cerebral resistance vessels.