Experts estimate one-third of sudden cardiac deaths happen at night when people are sleeping.
But doctors at Vanderbilt said heart patients can still get a safe, sound sleep without surgery or implants by wearing a device called a LifeVest.
The device will warn sleeping heart patients when something is wrong.
"In the event you heart goes into a dangerous or life-threatening rhythm, it can warn you. And if all else fails, deliver a therapy to get rid of that abnormal rhythm," said Dr. John McPherson of Vanderbilt University School of Medicine.
When the alarm senses an irregular heartbeat, the LifeVest can send shock pulses into the patient's chest that are 75 percent as strong as defibrillators.
Doctors say the vest snuggly fits under the patient's clothing and doesn't restrict movement.
"It's something you can learn to wear and put on yourself in a matter of minutes. It really allows you to have the freedom to walk around and move without any significant limitations," said McPherson.
The LifeVest is meant to help out people who have suffered heart attacks in the past or patients waiting on a defibrillator.
"This can be used as a bridge or insurance policy until they can get permanent therapy," said McPherson.
Only five minutes after cardiac arrest, patients may have permanent brain damage or die, but the monitor on the LifeVest responds instantly and may be the key to saving more lives.
The ZOLL Medical Corporation, which markets the product, says it has been prescribed to more than 75,000 patients.
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