Fridley-based Medtronic, Inc., on Monday received approval from the U.S. Food and Drug Administration (FDA) for a family of implantable defibrillators designed to deliver therapeutic shocks only when appropriate.

The Protecta portfolio of products includes cardioverter-defibrillators and cardiac resynchronization therapy defibrillators-which feature Medtronic's SmartShock technology.

Defibrillators are implanted in people's chests and deliver a shock to the heart when an irregular heartbeat is detected, but many patients experience a shock from the devices even when they don't need it. In fact, Medtronic cites studies that indicate that up to 20 percent of patients implanted with defibrillators may experience “inappropriate shocks.”

Medtronic says that a recent study-in which simulations of shocks were run through algorithms and patients were not physically implanted with defibrillators-projected that 98 percent of patients using the SmartShock technology will not experience inappropriate shocks one year following the implant, and 92 percent will be free of unneeded shocks five years after the implant.

“With recent studies showing that up to one in five patients may experience inappropriate shocks, this new technology can significantly mitigate that concern and will have a real-world impact on my patients' lives by improving quality of life,” Kent Volosin, a cardiologist at the University of Pennsylvania, said in a statement.

Medtronic will begin shipping the Protecta portfolio of products immediately. Medtronic says that its Protecta devices feature six new “Medtronic-exclusive algorithms” to deliver the proper shocks.

Little Canada-based St. Jude Medical, Inc., says that it too has developed technologies to reduce unnecessary shocks to patients. In a meeting with investors, Eric Fain, president of St. Jude's cardiac rhythm management division, said the company's ShockGuard technology has been successful in recent studies-indicating that 98.5 percent of patients using the technology would be free of inappropriate shocks one year after the device was implanted.

“And this data compares very favorably to that [which has] been published for Protecta,” Fain told investors. “We expect to be able to launch this worldwide in the middle of 2011.”

Medtronic is the second-largest publicly traded medical device manufacturer in Minnesota; the company reported $15.8 billion in its most recently completed fiscal year. St. Jude is the state's third-largest med-tech company.