Narrator: This is Science Today. Everyone knows that the human heart makes two sounds while pumping blood, but a weakened heart may actually make a third sound, which can be accurately detected by a device called a phonocardiogram. But medical professor Andrew Michaels of the University of California , San Francisco says they found that experienced doctors have a good chance of hearing it, too.
Michaels: We also looked at if the physician thought there was a third heart sound, did this correlate with weakened heart muscle based on the cardiac catheterization and ultrasound of the heart, and it did.
Narrator: Finding this third sound could mean early detection of certain serious heart conditions.
Michaels: There's three main causes of weakened heart muscle. The first is coronary artery disease, or blockages in the heart arteries that supply oxygen to the heart muscle. The second main cause is weakening of the heart muscle itself, usually due to a viral syndrome. And the third main cause is an abnormal valve problem that causes too much stress on the heart.
Narrator: For Science Today, I'm Larissa Branin.