Narrator: This is Science Today. The human heart may typically make two sounds, but weakened hearts can actually produce a third sound. This third heartbeat, called an S3, has long been known to be a common indicator of possible heart problems. Dr. Andrew Michaels of the University of California , San Francisco explains.
Michaels: When a physician hears this third heart sound, it signifies weakening of the heart muscle. And this has been something that's been taught to medical students and training physicians for the last hundred years.
Narrator: Michaels led a study that demonstrated that experienced physicians are better able to hear this third sound using just a stethoscope. He says this simpler method has its advantages.
Michaels: We do have fancier ways to image the heart with an echocardiogram or going to the cardiac cath lab or doing some other imaging of the heart, but those tests are not readily and immediately available. Some of them are invasive, and they're all expensive.
Narrator: For Science Today, I'm Larissa Branin.