A federal appeals court on Wednesday revived an earlier patent-infringement ruling about pacemakers against St. Jude Medical Inc. (STJ), but limited the company's exposure to financial damages.

The U.S. Federal Circuit Court of Appeals, which handles patent appeals, sent the case back to the district court so a judge can award damages to Guidant Corp. and Cardiac Pacemakers Inc., which filed the suit against St. Jude in 1996. Guidant is now a unit of Boston Scientific Corp. (BSX).

Cardiac Pacemakers alleged in its original lawsuit that St. Jude infringed on its patent for a pacemaker, an electronic device implanted in someone's chest that gives pulses or shocks to the heart to help it beat. A jury in 2001 awarded Cardiac Pacemakers $140 million in royalties for patent infringement but another court overturned the ruling.

The court ruled Wednesday that the infringement applies only when the product was used in the U.S., not internationally. St. Jude said the product in question was infrequently used in the U.S. As a result, the company says damages will be immaterial.

-By Jared A. Favole, Dow Jones Newswires; 202-862-9207; jared.favole@dowjones.com