The conventional wisdom has always been that the heart cannot generate new muscle cells so you die with the same heart you were born with.

However, back in 2001, experiments seemed to indicate that human heart muscle cells regenerate after a heart attack. Now another research study has revealed that heart muscle cells are renewed even without a heart attack. A big surprise.

The study revealed that when you're 25, about 1 percent of your heart muscle cells are replaced every year. Unfortunately, this declines to about half that rate by the time you're 75. Calculations suggest that about half of your heart's muscle cells are normally replaced over a lifetime.

The excitement around these findings is the suggestion that science might be able to develop methods or drugs to accelerate or induce heart muscle regeneration. Certainly this is an important finding considering about four hundred fifty thousand people die from heart attacks every year in the U.S.

Heart attacks, or myocardial infarction occur when the blood supply to a part of the heart is interrupted causing some heart cells to die. Most often the heart attack is caused by a blockage in one of the coronary arteries which results from atherosclerotic plaque.

The plague is an accumulation of lipids like cholesterol and white blood cells on the artery wall which can accumulate for years. Eventually, an area of plaque can break apart, causing a blood clot to form on the surface of the plaque.

If the clot becomes large enough, it can block the flow of oxygen-rich blood to the part of the heart muscle originally fed by the blocked artery. Those muscle cells can die and be replaced by scar tissue which impairs the heart.

If scientists actually found a way to regrow muscle cells in the damaged areas, many lives could be saved.