Is there a way to prevent the permanent, often disabling, damage to the heart and brain that occur from a heart attack or stroke? Mark Payne, M.D., assistant professor of pediatrics at Wake Forest University Baptist Medical Center, hopes that research he''ll conduct with a $600,000 grant from the National Institutes of Health will lead to an answer.
When heart and brain cells are temporarily deprived of oxygen, they produce chemicals when blood flow is restored that cause their own death. In adults, the temporary lack of oxygen to the cells is usually the result of a blood clot blocking the major vessels to the heart or brain. In children, it can sometimes happen after heart surgery.
Payne, a pediatric cardiologist, says that in about 5 percent of children undergoing heart surgery, blood flow is interrupted because the heart won''t restart on its own after being stopped for surgery. Or, a child''s condition may be unstable after surgery and the heart can stop.
When blood flow is restored to the cells, such as when someone is given cardiopulmonary resuscitation or a clot-busting drug, the cells begin to produce chemicals, called free radicals, that can cause them to die in a matter of days. From earlier research, Payne believes that this reaction may happen because of damage to the cells'' mitochondria, the part that makes energy for the cell.
"The mitochondria''s job is to make energy, so when it runs out of oxygen and fuel it begins to generate the free radicals," says Payne. "This cell death may happen over a matter of days. That''s why someone who has had CPR may appear to be fine at first, and then several days later may have signs of brain damage."
When a significant number of cells die in the heart, the heart can''t keep up with the body''s demands. When it happens in the brain, memory, speech or movement problems result.
With the research grant, Payne will further study cell injury and death to learn more about the process. He''ll also evaluate drugs that may have the potential to protect the mitochondria. Studies in individual cells and in animals have shown that certain drugs bind to the mitochondria and may prevent them from being damaged.
Payne''s research focuses on children, but could benefit adults as well. The three-year research project could lead to drugs that children could take a few days before surgery to protect their hearts and brains. Another possibility is that adults who are at high risk for stroke or heart attack could take the protective drugs.
"You can''t stop the stroke itself, but you may be able to protect the brain or heart tissue," said Payne.
Contacts: Karen Richardson, (336) 716-4453 or Jim Steele, (336) 716-3487.