Washington, Nov 16 - Scientists have figured out the link between Alzhemier's disease and chronic heart failure, two leading causes of death.

A team of US, Canadian and Italian bio-chemists and cardiologists, led by Johns Hopkins researchers, identified three changes in the chemical make-up of a key structural protein, called desmin, in dog's heart muscle cells.

The changes led to the formation of debris-like protein clusters, desmin, in heart muscle, similar to amyloid plaques seen in the brain tissue of Alzheimer's patients.

The protein alterations, which were reversed by surgically repairing the heart, occurred at the onset of heart failure. Symptoms may include fatigue, shortness of breath and enlargement of the heart.

"Our study leads us to believe that desmin plays a key role in heart failure," says lead study investigator and protein biochemist Giulio Agnetti, post doctoral fellow at Hopkins.

"Now we have a chemical target to research further and help us investigate what could be the underlying biological cause of heart failure and if it is like Alzheimer's, an amyloid-related disease," he said.

Further experiments by Hopkins scientists found the same chemical modifications to desmin in the heart muscle in four people already diagnosed with the disease, said a Hopkin's release.

Misshaped desmin proteins and amyloid-like debris had been previously reported in 2005 in mice genetically altered to develop chronic heart failure, providing the first biological link between the two chronic diseases.

Studies since have also reported desmin changes in failing animal hearts, but none detailed what the chemical changes were or how they might affect organ function. (IANS)