Medical-device makers Guidant ( GDT), St. Jude ( STJ) and Medtronic ( MDT) all received subpoenas from the Justice Department, which says it wants a range of information about the companies' heart devices.

Both Guidant and St. Jude Medical say they've received subpoenas from the U.S. Attorney's Office in Boston requesting documents on their practices regarding pacemakers, implanted cardiac defibrillators and related products.

Additionally, the U.S. Attorney in Minneapolis has asked for documents specifically pertaining to Guidant's Ventak Prizm 2 and Contak Renewal 1 and 2 devices. Older models of the Ventak Prizm and Contak Renewal devices were the subject of recalls earlier this year.

Medtronic said it received a subpoena from the U.S. Attorney's Office in Massachusetts requesting information on pacemakers, defibrillators and monitoring equipment, along with training and compliance materials relating to fraud and antikickback laws.

All three companies say they intend to cooperate fully with authorities.

Last week, health care giant Johnson & Johnson ( JNJ) said it would "consider alternatives" under its merger agreement with Guidant, which is worth $76 a share. The deal is expected to close by the end of October, pending a decision by the Federal Trade Commission.

Some analysts and investors have speculated J&J might lower its bid for Guidant in the wake of that company's product recalls, but the takeover price hasn't been changed.

Guidant shares were trading at $62.40 Wednesday, down $2.30, or nearly 4%. St. Jude shares were 3 cents lower at $48.24, and Medtronic fell 49 cents to $56.48.