Science / Medicine : Cocaine Slows Blood Flow to Heart

Tiny amounts of cocaine, smaller than those commonly given by doctors for anesthesia, can trigger a significant reduction in the flow of blood to the heart, a study shows.

Young, seemingly healthy cocaine abusers sometimes suffer chest pain or heart attacks, even though their heart arteries appear normal. Doctors have speculated that the drug causes spasms in blood vessels and temporarily chokes off the flow of blood to heart muscles.

“The importance of our findings was showing that this indeed happens,” said Dr. L. David Hillis. The study, conducted by Hillis and his colleagues at the University of Texas Southwestern Medical Center in Dallas, was published in last week’s New England Journal of Medicine.

In their experiment on 45 people, doctors tested cocaine’s effects on the heart when volunteers received doses that were about two-thirds the amount used for anesthesia. By contrast, people who abuse cocaine typically take six times this much.

“Even that small dose caused coronary blood flow to fall by about 15 to 20%,” Hillis said.

Hillis said that despite the finding, the medical use of cocaine as a anesthetic is safe. The volunteers showed no sign in their hearts of ischemia, or oxygen starvation.