Developments to Watch
Don't Take Off on an Empty Stomach
A snack and a beverage prior to boarding an airplane could do much more than just steady your nerves: It might also help prevent a heart attack or a loss of consciousness while in the air.
A study of 12 volunteers in a low-pressure chamber used to train pilots in Japan's air force found that those who hadn't eaten beforehand suffered a drop in blood pressure and a decrease in oxygen saturation in the brain and peripheral arteries. Eating and drinking before the tests boosted the heart's output and the blood flow to the brain, while oxygen levels in the brain and other organs also rose sharply.
Medical emergencies occur as often as once in every 800 flights, and more than half involve heart attack and loss of consciousness. The study, by Dr. Makoto Matsumura and colleagues at Saitama Medical School in Japan, was undertaken because of concern about the effects of low cabin pressure on airline passengers. Matsumura doesn't know exactly how much passengers might want to eat or drink before boarding their flights, as very heavy meals could strain the heart in people with heart disease. The volunteers in the study drank a 16-ounce soft drink and a modest lunch. Future studies will explore what effects different lunch menus have.Return to top
Perils of the Sporadic Workout
People who exercise only intermittently have an elevated risk of an exertion-induced heart attack--compared with those who exercise regularly, a study found. And in a separate report, researchers said that health clubs often failed to screen older members for heart disease and establish an emergency response plan, as recommended by the American Heart Assn.
The study of heart attack risks was based on data from health clubs. Researchers investigated 71 fatal heart attacks that occurred during a total of 182 million workouts by health club members. Almost half of the deaths occurred in those who exercised less than once a week.
The researchers emphasized that the mortality rate was low--one death in every 2.5 million workouts. Exercise is safe, and it remains an important way for people to lower their heart disease risks, said one of the study's authors, Barry A. Franklin, director of cardiac rehabilitation at William Beaumont Hospital in Royal Oak, Mich. But Franklin suggested that people should perhaps work out less vigorously if they don't exercise regularly.
In a separate study, researchers from the University of Massachusetts surveyed health clubs in Ohio and found that 28% failed to conduct screenings of members to identify potential heart risks. And nearly 60% of the clubs had no written medical-emergency response plans. Kyle J. McInnis, the study's principal author, said equipping gyms with automatic external defibrillators could save lives.Return to top
Bad Gums, Bad Heart? Could Be
One-third of those people who suffer heart attacks do not have the risk factors usually associated with such trouble: high blood pressure and high cholesterol. But several new studies add to the evidence that heart disease may be triggered by viruses or bacteria.
Dr. Efthymios Deliargyris of the University of North Carolina at Chapel Hill found, for example, that 85% of a small group of heart-attack victims also had severe gum disease, compared with 29% of a healthy control group. Researchers aren't sure how gum disease and heart disease are linked, but one possibility is that the diseased gums cause immune-system changes that can spur the formation of clots in coronary arteries.
In another study, Steve Kerrigan, of Dublin's Royal College of Surgeons in Ireland, found that an infection with H. pylori bacterium can encourage blood platelets to clump together--an important step in clot formation. And Dr. Deepak L. Bhatt of the Cleveland Clinic Foundation reported that a high white-cell count, an indication of infection, is also linked to elevated heart-disease risk. In yet another study, Dr. Jianhui Zhu and Dr. Stephen E. Epstein of the Cardiovascular Research Institute in Washington, looked at levels of antibodies to cytomegalovirus, which infects more than half of all U.S. adults by age 40. Levels of antibodies were highest in women whose arteries were narrowed and damaged by atherosclerosis, researchers found.Return to top