Carbon Monoxide Can Damage the Heart
Poisoning victims had higher long-term cardiovascular death rates, study found
TUESDAY, Jan. 24, 2006 (HealthDay News) -- Carbon monoxide can damage the brain, but new research suggests poisoning with the colorless, odorless gas can also cause serious harm to the heart.
Patients hospitalized for carbon monoxide poisoning are at a significantly increased risk of dying over the next seven years, especially from heart conditions, according to a report in the Jan. 25 issue of the Journal of the American Medical Association.
"All of the focus in carbon monoxide poisoning has been on the neurological complications," said study co-author Dr. Timothy D. Henry, director of research at the Minneapolis Heart Institute Foundation. "In this group of patients, we found that 40 percent had cardiovascular damage, as well."
Carbon monoxide is produced by the incomplete combustion of any fuel containing carbon, such as wood, gasoline, oil or coal. It combines with hemoglobin in the blood, reducing the flow of oxygen. Symptoms of carbon monoxide poisoning resemble those of the flu -- headache, dizziness, nausea.
About 40,000 Americans seek emergency room treatment for carbon monoxide poisoning each year. The incidence is higher in the winter, when people are more likely to be indoors, where the deadly gas can accumulate.
Henry and his colleagues tracked the health of 230 adults treated for moderate to severe carbon monoxide poisoning at a regional medical center. In addition to the usual procedure, they also ran tests for blood levels of troponin, a protein produced by damaged heart tissue.
The tests showed heart damage in nearly a third of the cases.
"A lot of these people were young, and they did not have a lot of heart disease," Henry said. "Only 5 percent of them died acutely [in the hospital], of bad burns and the like. Over the next seven years, the death rate in the group was three times higher than what you would expect from a normal population. The death rate for those with heart damage was 40 percent, compared to 15 percent if they had no heart damage at the beginning."
The risk of heart damage probably is not as high for people who experience mild carbon monoxide poisoning, Henry added. "It might not be that serious for people who are treated in the emergency room and go home," he said. "The people in our study had to be hospitalized. Still, you don't know if there is heart damage if you don't look for it."
And emergency room personnel generally don't look for it, Henry said. The message for them from this study is that, "just as these patients can have damage to the brain, they can have damage to the heart," he noted.
The first step is for emergency room personnel to be aware of the problem, Henry said. For moderate to severe cases of carbon monoxide poisoning, an electrocardiogram and a troponin test should be done to look for possible heart damage.
If heart damage is found, the patient should be followed and treated accordingly, Henry said. "We have therapies for decreased heart muscle function, such as beta blockers and ACE inhibitor drugs," he said. "Carbon monoxide poisoning has implications for heart function, so we have to take this seriously."
The report breaks new ground, said David G. Penney, a professor of physiology at Wayne State University, who has studied carbon monoxide extensively.
"We know that a certain fraction of people have acute [immediate] cardiac effects, but the fact that it has a long-term effect on increasing mortality is new," he said.
One slight drawback is that the study was not the carefully controlled trial that is the gold standard of medical research, Penney said. "But those studies are not easy to do. We can't knowingly expose people to carbon monoxide."
Find out more about preventing carbon monoxide poisoning at the U.S. Consumer Product Safety Commission.