A device that automatically detects early symptoms of congestive heart failure (search) has been implanted in a patient in the United States for the first time.

The device is designed to allow patients to get treatment earlier and stay healthier.

When fluid levels around the heart get too high, they can interfere with a normal heartbeat and cause death. The device implanted Monday in 70-year-old Antonio Comandari of Miami monitors the amount of fluid in the chest (search). If there is a buildup, doctors can prescribe medication to reduce it.

The InSync Sentry device, built by Medtronic Inc. of Fridley, Minn., is about the size of a cigarette lighter and transmits radio signals that can yield a computer readout on the heart.

The device costs about $30,000, lasts five to seven years and should be available for widespread use by February, said Comandari's physician, said Dr. Alberto Interian, chief cardiologist at Jackson Memorial Hospital.

It was approved by the Food and Drug Administration last month. About 400,000 Americans are candidates to receive the device, Interian said.

"More and more we're seeing patients who are living with severe congestive heart failure, where four or five years ago they'd be dead. Devices like this are improving the quality of life," he said.

Dr. Ann Bolger, a cardiologist with the American Heat Association, said the device could be helpful in catching problems quickly and helping people avoid hospitalization.

"The new part of this is basically implanting a remote sensor in the patient's body," Bolger said. "That is the very exciting part of this."

The device also works as a defibrillator (search) to jump-start hearts and make them beat in a normal rhythm.

Comandari has had three heart attacks and thought the fourth was coming last week when he felt dizzy and collapsed in bed. On Dec. 9, he was admitted with congestive heart failure.

"I'm happy because I was chosen to get a new life," he said.