Researchers discover type of "fuel" that the heart uses can contribute to the severity of heart failures

Jul 21 2005

Researchers have determined how metabolic pathways differ between healthy and failing hearts. Normally, a heart derives its energy from a balance of fatty acids and carbohydrates, specifically glucose.

But Dr. Gary Lopaschuk, a pharmacologist and professor in the University of Alberta Department of Pediatrics, and his colleagues in the U.S. and Italy have found that during the early stages of heart failure, the heart uses too much fatty acid and not enough carbohydrate; and then, later on, the heart doesn't use enough fat.

Lopaschuk thinks that better treatments for heart failure patients may be available now that they have discovered that the type of "fuel" that the heart uses can contribute to the severity of heart failures. There are existing drugs that can make the heart more productive, but they don't remedy the fact that the heart is still inefficient because a lot of oxygen is necessary for it to drive the same amount of contractile activity.

"Many forms of heart diseases have many pharmacological therapeutic approaches to treat it. But heart failure is a difficult one. If you're diagnosed with heart failure, your five-year prognosis isn't that good. There's a high likelihood of mortality. So there's a major push to find new approaches to treat heart failure," Lopaschuk said.

"Heart failure is not a situation where the heart completely fails, it is a condition in which the heart fails to provide even itself with enough blood under certain conditions," Lopaschuk added.

Heart failure can be brought on by heart attack, congenital heart defects, viral infections, hypertension and more. Because of this, Lopaschuk, an expert in regulatory pathways involved in energy metabolism in the heart, worked with his colleagues to find out how metabolic pathways differ between healthy and failing hearts.

"The heart has a huge need for energy. Everyone talks about the brain having a high energy demand, which it does, but the main energy user is the heart itself. Even though it pumps blood and oxygen around the rest of the body, the heart itself also consumes a huge amount of the oxygen that it takes in. And it's not unreasonable--it beats 24 hours a day," Lopaschuk said.