June 14 (Bloomberg) -- An experimental device to predict when a person may suffer a heart attack might be available in the U.S. next year, its Australian makers said.

HD Medical Group Ltd. said it will test its wireless device, which is able to detect heart noises that can signal an impending attack, on as many as 500 patients in a clinical trial at Melbourne's Alfred Hospital starting next month. Results of the trial may be available by the end of the year, with an application for approval to the U.S. Food and Drug Administration possible in early 2008, the company's managing director Jay Jethwa said in a telephone interview today.

Heart disease is the world's biggest cause of death and the U.S. government spends about $400 billion each year treating it, Jethwa said.

``In terms of being able to rapidly screen populations, this might be the answer we've been looking for,'' said Henry Krum, chairman of medical therapeutics at Monash University, who will lead the trial. ``It's simple, it's cheap, it's not particularly operator-dependent.''

The device works by sending and receiving low-voltage radio waves to and from the heart, similar to the way fishermen use sonar waves to locate fish, Jethwa said. It's a combination of the company's proprietary ViScope instrument and technology licensed from Australia's Commonwealth Scientific and Research Organization in December last year.

Heart Signals

Researchers are still trying to figure out what the signals the device gets back from the heart mean, Krum said.

``Whether it's the motion of the heart itself, whether it's the pressure that is generated within the heart, or whether it's the waveforms of the vessels that leave the heart, is still not entirely clear,'' he said.

The device, which hasn't been named yet, is better than a stethoscope because it doesn't depend on the user's hearing, and filters out ``ambient noise,'' Jethwa said.

Unlike echocardiography, or ECG machines, which monitor the heart's electrical activity, the device picks up the mechanical activity of the heart. It will also be cheaper and easier to use than ECG equipment, Jethwa said.

ViScope is a ``visual stethoscope'' that displays a patient's heart sounds on a liquid crystal display screen. A clinical trial of the device at the University of California San Francisco produced ``favorable initial results'' which the company will present at the American Society of Echocardiography's scientific sessions next week, Jethwa said.

To contact the reporter on this story: Simeon Bennett in Singapore at sbennett9@bloomberg.net.

Last Updated: June 14, 2007 06:44 EDT