• Blood pressure;
  • Hypotension;
  • Cerebral blood flow;
  • Attention;
  • Midodrine;
  • Doppler sonography


Previous research has demonstrated reduced cognitive performance and diminished cerebral blood flow in the case of chronic hypotension. We investigated whether these deficits can be reduced by pharmacological blood pressure elevation. Effects of the sympathomimetic midodrine were examined in 50 hypotensive individuals based on a randomized, placebo-controlled double-blind design. A paper–pencil test assessing performance in selective attention was presented. By means of transcranial Doppler sonography, blood flow velocities were recorded in both middle cerebral arteries at rest and during the execution of a cued reaction time task. The administration of midodrine led to an increase in blood flow velocities at rest as well as enhanced attentional performance. The degree of rise in flow velocities was positively correlated with performance enhancement. The increase in flow velocities observed during the execution of the reaction time task was stronger following drug administration.