Medtronic, the medical devices manufacturer, announced today that the malfunctioning of a key part of one of its heart defibrillation systems may have led to five patient deaths.

Normally the system, designed for patients at risk for cardiac arrest, delivers a jolt to reset the heart when it detects abnormal rhythms. The company found that in some cases, certain models of the leads that monitor the heart can fracture, leading to unnecessary shocks.

Medtronic is now asking doctors not to install these wires – the Sprint Fidelis model – any longer, but the company, along with the FDA, says that the estimated 268,000 patients who do have them in place do not need to have them removed. The risks associated with removing and replacing the leads are greater than those associated with leaving the potentially faulty wires in place. Instead, doctors can reprogram the system so that it will warn the patient if his or her leads go haywire. Think that’s making any of those patients feel better? Me neither.—Gregory Mone