New Tests Can Detect Heart's Ails; Arrhythmia Research Tech; Fitchburg, Mass. Arthrt.com.(HEALTH & MEDICINE)(UNDER THE MICROSCOPE)

Byline: Amy Reeves

Arrhythmia Research Technology, or ART, has been around for 22 years. But the tiny firm has flown under Wall Street's radar.

Like many small medical companies, it was founded to take advantage of a new technology. In this case, signal-averaged electrocardiography, or SAECG.

SAECG picks up cardiac "late potentials" -- signs of an imminent heart attack that would escape a normal ECG.

ART's Predictor software analyzes SAECG readings. It picks up and amplifies the subtle electric signals from late potentials, and cuts out electrical "noise."

For many years Predictor ran on the old DOS standard, but recently the firm completed a conversion to the Windows format.

Relying on one technology is always a risky business, so in 1992 the company bought Micron Products Inc., a maker of snaps and sensors for ECG machines. The firm is the nation's largest supplier of silver chloride sensors for this purpose. During the Predictor conversion, ART closed its original Austin office and moved to Micron's home in Fitchburg, Mass.