MONDAY, Aug. 22, 2005 (HealthDay News) -- Heart failure, the organ's inability to pump blood properly, is as much a matter of the brain as the heart, a new study suggests.
The research, which describes the brain damage seen in people with heart failure, was done by Ronald L. Harper, distinguished professor of neurobiology at the University of California, Los Angeles, and Mary A. Woo, an associate professor of nursing at UCLA. It appears in the August issue of the Journal of Cardiac Failure.
"We got together to do imaging studies," Harper said. "Our first paper in 2003 showed that heart-failure patients have a great deal of brain injury -- tissue loss in the regions of the brain that control blood pressure and heart rate."
Those areas are also damaged in people with depression, Woo said, noting that many people with heart failure are also chronically depressed.
While the 2003 scans showed damage to the brain, they did not determine whether the damaged areas were working correctly. The new study, which compared brain scans of six people with heart failure and 16 people without the condition, showed that the damage reduced the ability of the brain centers to do their work properly, Harper said.
It's not possible now to tell in detail the roles played by brain damage and heart damage in the physical problems experienced in heart failure, such as difficulty walking and the extreme fatigue that can occur with even moderate physical activity, Harper said.
The question now becomes which comes first -- "whether the brain damage causes heart failure or the heart failure causes the brain damage," Woo said.
But there's another possibility, Harper said. "We think that part of the injury may come from sleep problems. Half of heart failure patients have severe sleep disorders such as sleep apnea," he said.
Sleep apnea is consists of episodes during which breathing stops for 10 seconds or more. It can be associated with heart attack, stroke and heart failure. Scans done by Harper have shown damage to the same areas of the brain affected in heart failure in people with sleep apnea.
Whatever the cause-and-effect relationship, "the really important thing is for clinicians to realize that the brain is being affected, and that clinicians need to be evaluating brain function in heart-failure patients," Woo said.
You can learn more about heart failure from the American Heart Association.