Medtronic Pacemaker Lawsuit Alleges Azure Heart Device Required Removal Surgery

Lawsuit claims Medtronic pacemaker began malfunctioning within weeks of implantation, resulting in interference with the device’s ability to accurately detect and regulate heartbeats.

A Connecticut woman has filed a product liability lawsuit against Medtronic, alleging that a defective Azure dual-chamber pacemaker caused dangerous heart rhythm problems and abnormal electrical signals, ultimately requiring invasive surgery to remove and replace the device.

The complaint (PDF) was brought by Sandra Mizenko in Connecticut Superior Court on January 5, naming Medtronic Inc., Hartford Hospital and Hartford Healthcare Corporation as Defendants. Medtronic had the case removed to the U.S. District Court for the District of Connecticut on February 6.

Medtronic Azure pacemakers are classified by the U.S. Food and Drug Administration as Class III medical devices that are designed to send electrical impulses to the heart when it beats too slowly or irregularly.

According to the complaint, Mizenko underwent surgery to insert an Azure pacemaker in October 2023 at Hartford Hospital. However, within weeks of implantation Mizenko allegedly began experiencing serious complications linked to the device’s performance, including “atrial lead noise” and “double sensing,” both of which can interfere with the device’s ability to accurately detect and regulate heartbeats.

As a result of these malfunctions, Mizenko allegedly developed sinus node dysfunction, a condition in which the heart’s natural pacemaker fails to generate proper electrical signals, leading to symptoms such as dizziness, fatigue, fainting and abnormal heart rhythms.

The complaint further alleges that testing revealed dangerously high lead impedances exceeding 3,000 ohms, prompting the device to switch from bipolar to unipolar pacing. Lead impedance refers to the resistance encountered by electrical signals traveling through pacemaker leads that connect the device to the heart. Abnormally high impedance levels, such as those experienced by Mizenko, can indicate lead malfunction or poor electrical conduction, increasing the risk that pacing signals will not be delivered properly when needed.

Due to these issues, Mizenko alleges she was forced to undergo a second, invasive surgery in December 2023 to have the Azure pacemaker removed and replaced with a different device. The lawsuit claims the removal procedure caused additional pain, emotional distress and anxiety, with some of the injuries being permanent in nature.

“As a direct and proximate result of the foregoing, Plaintiff Sandra Mizenko has and will continue to suffer pain, mental anguish, frustration and anxiety over the fact that she required a second surgery.”

— Sandra Mizenko v. Medtronic Inc. et al

Mizenko alleges Medtronic violated the Connecticut Products Liability Act by selling an Azure pacemaker that was defectively designed and unreasonably dangerous, while failing to adequately warn physicians and patients about risks tied to atrial lead noise, double sensing and related complications. She claims Medtronic knew or should have known the device could malfunction in this manner but failed to take corrective action or provide sufficient warnings.

Her complaint seeks compensatory damages for medical expenses, pain and suffering and other losses associated with the implantation and removal of the pacemaker.

Pacemaker Injury Lawsuits and Recalls

This is not the first case that has been filed over Medtronic pacemakers in recent months. At the end of last year, an Oklahoma man’s lawsuit argued that StarFix leads in his father’s Medtronic pacemaker did not detach properly during removal surgery, tearing a vein in the heart, which resulted in brain damage and death.

In addition to the issues faced by Medtronic devices, Boston Scientific has also issued at least two pacemaker recalls over the past year, due to serious injury risks.

In October 2025, federal regulators indicated that some Boston Scientific Accolade and Accolade Proponent pacemakers may suddenly switch into Safety Mode, a limited-function state that could put patients at risk of serious injury or death.

A prior Boston Scientific pacemaker recall was announced in February 2025, after it was found that certain models of pacemakers manufactured by the company may need early replacement due to a similar malfunction of the Safety Mode, which resulted in at least 832 injuries and two deaths.

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