Medtronic Inc. has won U.S. approval for a new generation of implantable defibrillators designed to cut back on inappropriate shocks delivered by the devices, the company said on Monday.

A defibrillator is designed to shock a dangerously irregular heartbeat back to its normal rhythm.
According to Medtronic, studies estimate up to 20 percent of patients with implantable defibrillators may experience inappropriate shocks, due to a benign arrhythmia or electrical noise sensed by the device.

Findings from a study based on a statistical model showed that 98 percent of patients using devices with its SmartShock technology will be free of inappropriate shocks one year after implant and 92 percent will be free after five years, Medtronic said. The company said it will begin shipping the Protecta line of products immediately.