These failures may result from a defective battery, fractured lead, software or programming error, inadequate warning, or another device malfunction. Determining what happened requires more than reviewing the patient’s outcome. Device interrogation data, stored electrograms, battery and lead records, programming history, medical records, recall information, and the device itself may be essential to proving whether a preventable cardiac-device failure caused the injury.

Pacemaker Recalls Show How Device Failures Can Develop

In March 2026, Boston Scientific initiated an expanded correction involving ACCOLADE-family pacemakers and cardiac resynchronization therapy pacemakers. The FDA classified the action as a Class I recall, the agency’s most serious recall category.

The action followed earlier concerns involving battery performance and the potential for certain devices to enter an irreversible “Safety Mode.” According to the FDA’s safety communication on ACCOLADE pacemakers, Safety Mode can change how the pacemaker senses and paces the heart and, in some patients, may interrupt effective pacing. Boston Scientific’s 2026 action expanded the affected device population and made updated software available to address the issue.

The ACCOLADE history illustrates why identifying the exact model, serial number, battery history, device alerts, and software status can matter after an unexplained cardiac event. A patient may have had an implanted device for years before a manufacturer warning, software correction, or recall provides additional information about the potential failure mechanism.

Pacemaker litigation has also followed these developments. In June 2026, a proposed Canadian class action involving Boston Scientific pacemakers was filed alleging that battery defects in certain devices caused or increased the risk of premature failure and replacement. Those allegations have not been established as findings of liability, but the case illustrates how regulatory actions, product testing, manufacturer knowledge, and individual device performance can converge in cardiac-device litigation.

Defibrillators have presented different failure risks. The FDA previously announced a Class I recall involving certain Medtronic ICDs and CRT-D devices that could deliver reduced or no energy when high-voltage therapy was required. A reduced-energy shock or failure to shock can leave a life-threatening arrhythmia untreated.

These recalls do not establish that every covered device is defective or that a recalled device caused a particular patient’s injury. They do show why a serious pacemaker or ICD failure requires investigation of the specific device, its components, programming, performance data, recall history, and the cardiac event itself.

What Happens When a Pacemaker Fails?

A pacemaker monitors the heart’s electrical activity and delivers electrical impulses when necessary to maintain an appropriate rhythm. For some patients, particularly those who are pacemaker-dependent, reliable pacing is critical.

A pacemaker failure can occur when the device fails to deliver a pacing impulse when it should, fails to properly detect the patient’s heart rhythm, or cannot deliver sufficient electrical energy to stimulate the heart.

Potential failure mechanisms include:

• Premature battery depletion or battery malfunction
• Fractured, damaged, or displaced leads
• Lead insulation failure
• Electrical connection problems
• Software or firmware malfunction
• Failure to sense the patient’s cardiac activity correctly
• Inappropriate inhibition of pacing
• Manufacturing defects
• Programming problems
• Problems communicating with remote monitoring systems

Pacemaker malfunction can produce symptoms such as dizziness, fainting, shortness of breath, palpitations, weakness, or loss of consciousness. The National Heart, Lung, and Blood Institute advises patients with implanted cardiac devices to report concerning symptoms and device-related problems to their healthcare providers.

For a patient who relies heavily on the device, an interruption in pacing can become a medical emergency.

What Happens When an Implantable Defibrillator Fails?

An implantable cardioverter defibrillator continuously monitors the heart for potentially fatal rhythms such as ventricular tachycardia or ventricular fibrillation. When the device detects a qualifying rhythm, it can deliver electrical therapy intended to restore a safer rhythm.

An ICD failure may involve two very different problems.

The first is failure to provide treatment when treatment is required. The ICD may fail to detect a dangerous rhythm or may detect it but fail to deliver adequate electrical energy.

The second is inappropriate therapy, including shocks delivered when the patient’s rhythm does not require them.

ICD problems can involve:

• Failure to recognize a dangerous arrhythmia
• Low-energy or absent shock delivery
• Lead fracture or displacement
• Abnormal electrical resistance
• Battery problems
• Capacitor or pulse-generator malfunction
• Software errors
• Sensing abnormalities
• Incorrect programming
• Inappropriate shocks

The FDA has previously classified recalls involving ICDs as Class I recalls when device problems could cause serious injury or death. One Medtronic recall involved certain ICDs and cardiac resynchronization therapy defibrillators that could deliver reduced or no energy during high-voltage therapy.

That distinction matters. A defibrillator can appear functional during everyday life but still fail during the exact cardiac event it was implanted to treat.

Battery and Power-System Problems Can Turn Into Cardiac Device Failures

Battery and power-system problems can affect whether a pacemaker or defibrillator can deliver therapy when needed. These failures may develop gradually due to premature battery depletion or arise from defects in internal circuitry, capacitors, or other components that control power delivery.

Potential consequences can include:

• Loss or reduction of pacing
• Inability to deliver a full defibrillation shock
• Unexpected changes in device function
• Premature device replacement
• Emergency revision surgery
• Loss of therapy before the device reaches its expected replacement date

In a suspected failure case, battery history, voltage trends, device alerts, interrogation reports, and manufacturer testing may help determine whether the problem originated in the power system or another component.

Because implanted cardiac devices are sealed systems, a significant internal failure often cannot be corrected without replacing part or all of the device. That makes early preservation of device data and any explanted hardware especially important when a serious injury or death follows an unexpected loss of function.

Cardiac Leads Can Be Just as Important as the Pacemaker or Defibrillator

The pulse generator receives and delivers electrical information through leads connected to the heart. A pacemaker or ICD can therefore malfunction even when the generator itself is operating properly.

Lead problems can include fracture, insulation damage, displacement, connector problems, or abnormal electrical signals.

A damaged lead can prevent a pacemaker from delivering effective pacing. In an ICD, lead failure can prevent the device from accurately detecting a dangerous rhythm or delivering appropriate therapy. Sensing abnormalities can also cause inappropriate treatment.

FDA recall records also show that defibrillator leads themselves have been subject to Class I recalls, reinforcing the need for an investigation to identify every implanted component rather than focusing only on the main pulse generator.

How Can You Tell Whether a Cardiac Device Actually Failed?

A serious cardiac event after pacemaker or ICD implantation does not automatically establish that the device malfunctioned.

The key question is whether objective evidence shows that the device failed to perform as designed, programmed, or represented and whether that failure contributed to the patient’s injury.

Relevant evidence can include:

• Device interrogation reports
• Stored electrograms and rhythm information
• Remote monitoring data
• Battery status and voltage history
• Lead impedance measurements
• Device alerts
• Programming records
• Implant and revision records
• Device model and serial numbers
• Unique Device Identifier information
• Manufacturer communications
• FDA recalls and safety communications
• Emergency medical records
• ECG and telemetry data
• Records showing the patient’s underlying cardiac rhythm at the time of the event

This evidence can help determine whether the problem involved the pulse generator, battery, leads, programming, sensing system, monitoring process, or another cause.

Preserving an Explanted Pacemaker, ICD, or Lead Can Be Critical

One of the most important issues after suspected cardiac device failure is preserving the actual product.

If surgeons remove or replace a pacemaker, ICD, pulse generator, or lead, the removed components may contain evidence that cannot be recreated later. Patients and families should focus first on appropriate medical treatment, but the device should be preserved when possible rather than destroyed or returned without documentation.

Important evidence can include:

1. The explanted pulse generator
2. Removed leads and connectors
3. Device identification cards
4. Implant labels and serial numbers
5. Packaging and manufacturer records
6. Device interrogation reports
7. Remote monitoring records
8. Recall or correction notices
9. Communications between the manufacturer and healthcare providers
10. Medical records from the original implantation through the failure and revision

The FDA’s Unique Device Identifier system can also help identify the exact device involved.

This type of evidence preservation is a central part of a sophisticated medical device product liability investigation.

Who May Be Responsible for a Pacemaker or Defibrillator Failure?

Responsibility depends on why the device failed.

The device manufacturer

A manufacturer may face a product liability claim when evidence supports a defective design, a manufacturing defect, an inadequate warning, a software problem, a battery defect, a defective lead, or another product-related failure.

Manufacturers may also possess internal testing, complaint, failure analysis, quality control, and post-market surveillance information relevant to determining whether similar failures occurred.

Healthcare providers

Not every cardiac device case is solely a product case.

A physician, hospital, cardiac electrophysiology practice, or another provider may also require an investigation if the evidence suggests problems with implantation, programming, follow-up, monitoring, or response to device warnings.

Those questions may implicate medical malpractice in addition to product liability.

Multiple responsible parties

Some cases involve both.

For example, a manufacturer may have issued a warning about a device problem while a provider’s records show that an alert was not addressed. A lead may have malfunctioned while remote monitoring data documented developing abnormalities. A defective component may also have been implanted or programmed in a way that contributed to the outcome.

A complete investigation should examine the entire sequence rather than assuming either the manufacturer or the medical provider was solely responsible.

Does an FDA Recall Mean Someone Has a Pacemaker or Defibrillator Lawsuit?

No. A recall alone does not prove that a particular device caused an injury.

FDA medical device reports and recall information can identify safety concerns, but they must be evaluated alongside device- and patient-specific evidence. The FDA expressly cautions that adverse-event reports by themselves do not establish causation or event rates.

A stronger investigation connects the specific device and failure mode to the patient’s cardiac event through interrogation data, medical records, product history, expert analysis, and other objective evidence.

What Injuries Can Result From a Pacemaker or ICD Failure?

Depending on the patient’s underlying condition and the type of malfunction, cardiac-device failure can contribute to:

• Dangerous bradycardia
• Ventricular tachycardia or ventricular fibrillation
• Syncope or loss of consciousness
• Cardiac arrest
• Hypoxic brain injury following prolonged loss of circulation
• Falls or traumatic injuries caused by sudden fainting
• Emergency hospitalization
• Emergency device revision or replacement
• Additional surgical complications
• Worsening heart failure
• Death

The injury analysis must still establish causation. A patient with serious preexisting cardiac disease can experience a cardiac emergency even when an implanted device functions properly. That is why these cases often require close analysis by cardiac electrophysiology, biomedical engineering, product, and other appropriate experts.

When Should a Pacemaker or Defibrillator Failure Be Investigated?

A legal investigation may be warranted when a patient suffers a catastrophic injury or death, and there is evidence suggesting that an implanted cardiac device failed to provide the therapy it was supposed to deliver.

Potential warning signs include:

• Device interrogation identifies abnormal performance
• The device failed to pace during a documented period of bradycardia
• An ICD did not shock during a qualifying dangerous rhythm
• A delivered shock had insufficient energy
• A lead fractured, displaced, or malfunctioned
• Battery depletion occurred earlier than expected
• The device unexpectedly entered a limited operating mode
• The patient required emergency revision or replacement
• The manufacturer issued a recall, correction, or safety notice involving the same model
• Remote monitoring produced alerts before the injury
• Records show unresolved warnings about device performance

Not every one of these facts establishes liability; they are reasons to investigate further.

Cardiac Device Failure Cases Require the Product and the Medicine to Be Reconstructed Together

Pacemaker and defibrillator cases cannot be resolved by asking only whether the patient experienced a poor cardiac outcome. The investigation must determine what rhythm occurred, what the implanted device detected, what therapy it attempted to deliver, whether the device and leads performed properly, and whether another action could have prevented the injury.

McEldrew Purtell handles complex medical device and implant claims involving catastrophic injury and wrongful death. These cases may require a coordinated review of the product, device data, medical records, FDA history, manufacturer information, and medical care related to the failure.

Talk to McEldrew Purtell About a Serious Cardiac Device Failure

If you or someone in your family suffered catastrophic injury or a death after a pacemaker, implantable cardioverter defibrillator, CRT device, or cardiac lead failed to work as expected, McEldrew Purtell can investigate whether a defective medical device, inadequate warning, monitoring failure, medical negligence, or a combination of failures contributed to the outcome.

Contact McEldrew Purtell for a free consultation to discuss what happened and the evidence that may need to be preserved.