Fixing hearts one cell at a time by replacing damaged tissue with new.

Byline: Tracy Wheeler

AKRON, Ohio _ When a heart attack strikes, a roadblock in an artery brings blood to a halt, depriving the body's most essential muscle of oxygen. In less than a minute, areas of the heart begin to die and turn to scar tissue.

Once scarred, the heart stays that way, leaving the surviving areas to take on a heavier load.

But what if it didn't have to be that way?

What if that scar tissue could be replaced with working muscle? And what if new blood vessels could grow to restore the stifled blood flow that led to the heart attack in the first place?

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Research being presented at this month's annual meeting of the American Heart Association in Chicago is slowly turning these questions from ``What if?'' into ``How soon?''

In hospitals around the world, ailing hearts are growing new muscle after being injected with cells taken from the patient's bone marrow or from muscles in the arms or legs. And new blood vessels are building detours around blocked arteries after damaged hearts are infused with the patient's skin cells or with cells harvested from donated umbilical cord blood.

``It's a really important step,'' said Dr. Patrick McCarthy, a cardiac surgeon at the…