Research suggests widespread problems with St. Jude heart device

New research suggests a sometimes-lethal problem with a St. Jude Medical Inc. heart device could be widespread, though the full scope of the issue remains unknown.

The data, from a seven-hospital study, found that 67 of 712 of the devices -- wires, known as leads, that connect defibrillators to patients' hearts -- had failed as of the end of December. The findings, presented at a meeting of the Heart Rhythm Society in Boston, represent the first large study to evaluate the problem.

Researchers also examined X-ray images of 110 of those patients. In 25 percent of those cases, wires inside the defibrillator leads had visibly broken through their insulation, a hallmark problem of St. Jude's troubled Riata-series devices. Of those, nearly one-third also had electrical problems.

Defibrillators zap patients' irregular heartbeats back to a normal rhythm with a shock of electricity. If they fail to work, a patient could die. They can also jolt patients when the shock is not needed. Both problems were among the types of lead failures identified by researchers.

St. Jude stopped selling the Riata leads in 2010, and they were recalled in December.

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