July 8, 2009

Hypertension Hampers Blood Flow to the Brain

Anger may make you red in the face, but new research shows that rush of blood may be cut off by high blood pressure -- posing a potential risk to the brain.

The University of Southern California and Cedars-Sinai Medical Center evaluated 30 healthy volunteers (19 to 60 years of age) and 28 patients with high blood pressure (38 to 64 years of age). Participants took part in numerous tasks provoking anger and mental stress involving reading and arithmetic. Researchers used ultrasound imaging to analyze carotid artery reactivity and brain blood flow in response to the mental stress.

In the healthy volunteers, mental stress caused vasodilatation and a net increase in brain blood flow. These results were absent in the patients with high blood pressure.

"Inappropriate vasoconstriction, or lack of dilation in response to mental stress in stable coronary heart disease, contributes to the genesis of myocardial ischemia and confers an increased risk in patients with coronary artery disease," Tasneem Naqvi, M.D., of the University of Southern California and Cedars-Sinai Medical Center, was quoted as saying. "It will be interesting to see whether the lack of mental-stress-induced dilation we found defines subjects at increased risk of future cerebral events."

SOURCE: BioMed Central's open access journal, Cardiovascular Ultrasound