Defibrillators save lives by maintaining regular heartbeats in patients with conditions such as ventricular fibrillation. One of the most widely used defibrillators in the United States is the Medtronic defibrillator, a device surgically implanted into the body of a patient to monitor the rhythm of the heart, correcting the rhythm if the heart begins to beat too fast. The part of the defibrillator that connects to the heart is a lead wire.
The lead wire in 90 percent of Medtronic’s defibrillators since 2004 was the Sprint Fidelis lead wire, placed inside of some 268,000 patients, according to the Wall Street Journal. Within the first few years of use, patients with Medtronic defibrillators that contained the Sprint Fidelis lead wires ended up in hospitals with broken lead wires. When this lead wire breaks, it is possible that the lead wire will emit a large and painful shock and the broken lead wire can prevent the defibrillator from sending an essential, lifesaving jolt to the heart.
Defibrillator lead fractures typically occur near the generator, at fixation points (such as the point of venous entry), and at sharp bends in the lead, and these breaks are rare.
Researchers at Medtronic developed the Sprint Fidelis lead wire to replace the Sprint Quattro. The new wire was much thinner than the older version, and not thoroughly tested in humans before becoming widely available on the market. While Medtronic has not disclosed the precise mechanism of how these Sprint Fidelis lead fracture failures occurred, it appears that the defect is due to the small diameter of the coil and conductors in the lead. Because of this, the lead is subject to stress damage both during and after implanting the defibrillator. A lead fracture occurs when the conductor is critically overstressed. It quickly became clear that this ultra-thin design was not as resilient as the previous model, as patients from across the country began coming to their doctors with fractured Sprint Fidelis lead wires.
Deaths and Injuries
Doctors connected the Sprint Fidelis to five deaths and more than 1,000 more patients suffered a wide range of side effects from the dangerous leads. The only solution for the problem of fractured lead wires is a surgery to replace the lead wire which is not a simple task, as the procedure can tear the tissue of the blood vessels and heart. Due to these hazards, doctors and the U.S. Food and Drug Administration (FDA) recommend that patients with these defibrillators not have the surgery to remove the faulty wire unless they were broken, leaving approximately 235,000 patients with defibrillators with defective lead wires still inside their chests, but not fractured. In a letter to patients in 2007, Medtronic informed patients that those with a Sprint Fidelis lead wire “…are more likely to experience complications from removal than from a problem with a Sprint Fidelis lead,” leaving patients and their doctors faced with a complicated decision.
Because of the issues with the leads, Medtronic stopped producing and selling them. Five people died because of fractures in their Sprint Fidelis leads, leading to unnecessary electrical discharges or defective sensing and capturing of electrical cardiac impulses. The FDA investigated the situation, and found that more patients were affected than the company originally thought.
Recall of Medtronic Defibrillator
Beginning in October 2007, Medtronic recalled the Sprint Fidelis leads, model numbers 6930, 6931, 6948 and 6949, and requested that doctors closely monitor their patients with these leads implanted. As a result, Medtronic put out a voluntary recall of these unsound leads to limit the further latent harm for patients.
Many injured patients retained lawyers to help them understand their legal rights and seek restitution from Medtronic. At the time of this writing, Medtronic has not yet settled any of the pending lawsuits nor have they settled any of the defective lead cases.
- Steiner RM, Morse DP, Tegtmeyer CJ. Pacemaker lead pseudo-fracture. Radiology 1982;143:793.
- Weissman JL, Kanel KT. Ligature causing pseudofracture of a cardiac pacemaker lead. AJR 1996;166:464-465.