Cigarette smoke worsens heart attacks
By Janet Raloff
People at risk of heart attacks should avoid smoke-filled rooms, a new study suggests. Researchers have found that lab rats were far less likely to survive a heart attack if they had regularly breathed secondhand cigarette smoke during the previous week.
The finding “was a real shock to us,” notes cardiovascular physiologist Paul F. McDonagh of the University of Arizona Health Sciences Center in Tucson.
For a week, one of his colleagues exposed the rodents to smoke equivalent to that experienced by a person in a smoky bar for 3 hours a day, says McDonagh. Then the scientists temporarily clamped an artery of each rat, inducing heart attacks, and did the same to animals that had remained smokefree. Fully 80 percent of the smoke-exposed rats died within the hour and a half following the induced heart attack, but only 30 percent of the smokefree rodents died during that critical period.