'Black Box' For The Body

Tracking the risks and causes of a heart attack might make the difference between life and death for some. But sometimes, such as when there are other obligations to fulfill, heart patients can't be confined to a bed to monitor their status.

About 25 percent of Americans can expect to have a passing out spell at some point in their lives, and 3 percent of these cases result in hospitalization. As many as 50 percent of the patients who have an extensive and expensive evaluation for a passing out spell have no diagnosis and the problem becomes recurrent.

Early Show medical correspondent Dr. Emily Senay explains that until now, it was only possible to monitor a person's heartbeat outside of the doctor's office for a few days. But a new tiny device that's implanted under the skin is giving doctors a way to get continuous information about the heart's rhythm for more than a year.

"I was at work talking to somebody and [I] just passed out," says heart patient Richard Kleeman. "No warning, whatsoever."

Despite numerous tests, Kleeman's doctor could not find out the cause of his fainting spells.

"It was always on your mind that you could pass out," says Kleeman. "I could be driving, I could be doing anything and it was a big strain on the mind."

Passing out without warning can be caused by many things, but the most dangerous cause is from an abnormal heartbeat. It's often easy to miss the problem using most tests because it only occurs sporadically.

The new palm-size heart monitor implant, called a loop recorder, is similar to an airliner's "black box," but for humans. The device has an EKG in it and it is inserted under the skin through a small incision that's about an inch wide.

When Kleeman fainted again, his loop recorder caught the problem.

"This was the first time in two-and-a-half years we were able to make a diagnosis of what caused his problem and how to effectively treat it," says Greenberg.

The doctor gave Kleeman a pacemaker after his heart was shown to have stopped for 10 to 15 seconds.

Harry McAlpine has had a loop recorder for more than a year since he passed out. So far his doctors have found no problems.

"We don't know why I passed out," says McAlpine. "I hope they'll say that it's probably something that will never happen again and they'll take the recorder out if it happens again."

Compared with the dangers of a serious heart problem the risks of having the device implanted are low and include the small chance of infection.