Updated July 19, 2026.
A heart device battery is smaller than the average snack bar, but its job description is enormous: keep monitoring the heart, deliver precisely timed electrical impulses, communicate with medical equipment, and do all of that reliably for years. That is why a battery-related recall involving implanted pacemakers and cardiac resynchronization therapy pacemakers deserves attention without causing unnecessary panic.
The current action centers on Boston Scientific’s ACCOLADE family of pacemakers and CRT-P devices. A battery manufacturing issue can cause high internal battery impedance, particularly later in a device’s service life. Under certain high-power conditions, such as device interrogation or wireless telemetry, the battery may temporarily underpower the system and trigger an irreversible operating state known as Safety Mode.
The word “recall” sounds as though every patient should race to an operating room before breakfast. That is not what regulators or heart-rhythm specialists are recommending. This recall primarily involves a software correction, closer monitoring, identification of higher-risk patients, and replacement when specific warning signs appear. Patients should not ignore the notice, but they also should not assume their device has already failed.
What Heart Devices Are Included in the Recall?
The affected product family includes multiple Boston Scientific pacemakers sold under the ACCOLADE, PROPONENT, ESSENTIO, and ALTRUA 2 names. It also includes VISIONIST and VALITUDE cardiac resynchronization therapy pacemakers, commonly called CRT-P devices.
Specific models include single-chamber, dual-chamber, standard-life, and extended-life pacemakers. The March 2026 correction expanded the advisory population to include all serialized dual-chamber extended-life pacemakers and CRT-P devices in the ACCOLADE family. Certain standard-life devices are also included based on their use-by dates and individual model and serial numbers.
The FDA recall database lists approximately 685,776 units distributed worldwide under the 2026 correction. That number represents devices in commerce, not confirmed battery failures. Most affected devices are not expected to experience the malfunction, and a device’s presence on an advisory list does not mean it has stopped working.
How Patients Can Identify Their Device
Patients should locate their implant identification card, which usually lists the manufacturer, model, and serial number. A cardiologist, electrophysiologist, or device clinic can also retrieve this information from medical records or during device interrogation.
Do not rely only on the brand name printed on a card. Two pacemakers with similar names may have different model numbers, manufacturing dates, firmware versions, or battery histories. The device clinic is the best place to confirm whether a particular implant is included and what action is appropriate.
What Went Wrong With the Batteries?
The problem is more complicated than a battery simply “running out early.” Some battery cathodes were produced using a processing technique that could leave a higher concentration of lithium salts. As the device ages, those materials may contribute to increased internal battery impedance.
Impedance is resistance to electrical flow. Imagine trying to drink through an increasingly narrow straw. The drink is still there, but delivering it quickly becomes more difficult. Similarly, a high-impedance battery may appear to have remaining energy but struggle when the device suddenly requires more power.
Higher-power operations can include communication with an in-clinic programmer, wireless telemetry, or remote-monitoring activity. During one of these operations, the battery voltage may temporarily drop. The pacemaker can respond by resetting itself. If three power-on resets occur within 48 hours, the device may permanently enter Safety Mode.
Why Safety Mode Can Still Be Dangerous
Safety Mode is an intentional backup feature designed to keep basic pacing available after the device detects a serious component problem. Unfortunately, “basic” is the important word. The settings are fixed and cannot be customized for the individual patient’s heart condition.
In the affected devices, Safety Mode changes pacing to a single-chamber configuration with fixed settings. It also uses unipolar sensing and pacing. For some patients, especially those who depend heavily or completely on their pacemaker, these settings may not provide reliable or comfortable support.
Possible consequences include interrupted pacing, pauses, an unusually slow heartbeat, fainting, skeletal muscle stimulation, phrenic nerve stimulation that may feel like twitching or hiccups, and worsening heart failure. Unipolar sensing may also detect muscle activity as though it were heart activity, potentially causing the pacemaker to withhold a needed pulse.
Safety Mode also consumes more power, so an earlier battery-life estimate may no longer be dependable after the mode is activated. A device that enters Safety Mode generally requires replacement rather than simple reprogramming.
Reported Injuries and Deaths
According to the FDA’s May 2026 correction notice, Boston Scientific had reported four deaths and 2,557 serious injuries associated with the issue as of March 18, 2026. Regulatory reports describe events associated with a device problem; they do not automatically establish that the battery issue directly caused every reported outcome.
The Heart Rhythm Society reported that three patients experienced Safety Mode activation related to high battery impedance, developed syncope requiring hospitalization, and later died. Another patient died following a device-replacement procedure. These outcomes explain why the correction is classified as the most serious type of recall, even though the failure remains uncommon across the overall device population.
What Is the Brady SMR6 Software Correction?
Boston Scientific introduced an earlier update, Brady Software Maintenance Release 5, or SMR5, in August 2025. It was designed to detect elevated battery impedance, generate a warning, and disable certain wireless telemetry functions before those functions could place enough demand on the battery to trigger Safety Mode.
However, clinicians later identified unintended behaviors. Wireless telemetry was not disabled in every scenario, and the presence of a magnet could cause a false-positive battery test. In some cases, the system could mistakenly disable wireless communication or display a misleading monitoring message.
The newer Brady SMR6 update, released as programmer software version 2.05, is intended to correct those problems. It improves the handling of telemetry wake-ups and resolves the magnet-related false-positive behavior identified with SMR5.
The update is installed during an in-person device interrogation using an updated LATITUDE Model 3300 programmer. It is not a smartphone update, a home download, or something a patient can install by pressing buttons on the bedside monitor.
All ACCOLADE-family pacemakers and CRT-P devices covered by the correction should be evaluated for the SMR6 upgrade. A firmware number shown on the clinical follow-up report can help the device team determine whether SMR5 or SMR6 has already been installed.
What Patients Should Do Now
1. Keep Every Device-Clinic Appointment
Patients should continue their normal medical care and attend scheduled device checks. Missing a follow-up because the pacemaker “feels fine” is not a reliable strategy. Pacemakers are wonderfully quiet when working correctly, and many technical problems can be detected before the patient notices symptoms.
Routine interrogation allows clinicians to review remaining battery longevity, voltage behavior, impedance, pacing dependence, lead performance, alerts, recorded rhythms, and firmware status. Pacemaker batteries commonly last many years, often roughly 8 to 15 years depending on the model, settings, and amount of pacing required. The advisory concerns abnormal battery behavior, not ordinary end-of-life depletion.
2. Confirm That Remote Monitoring Is Connected
Remote monitoring can transmit device information to the medical team and help identify alerts or loss of communication. Patients should keep their communicator plugged in, positioned as instructed, and connected to the required cellular or internet service.
Remote monitoring is valuable, but it is not an emergency response system and may not be watched every minute. Under SMR6, certain devices with disabled wireless telemetry may appear on a “Patient Not Monitored” list after a delay rather than generating an immediate remote-monitoring-disabled alert. Patients should follow their clinic’s instructions instead of assuming silence means everything is perfect.
3. Do Not Request Automatic Surgery Without an Evaluation
Current recommendations do not support replacing every affected pacemaker as a precaution. Generator replacement is generally less complex than the original implant, but it remains a surgical procedure with possible risks, including bleeding, infection, anesthesia complications, damage to existing leads, and problems affecting pacing-dependent patients during the exchange.
Boston Scientific and the Heart Rhythm Society state that preventive replacement before confirmed high battery impedance is generally not recommended under the current ACCOLADE advisory. Replacement is recommended when high impedance causes specific telemetry disablement, when the device enters Safety Mode, or when the treating team determines that an individual patient’s risk justifies intervention.
4. Take New Symptoms Seriously
Patients should contact their heart-device team promptly for new lightheadedness, near-fainting, unusual fatigue, palpitations, persistent twitching, unexplained hiccup-like sensations, shortness of breath, swelling, reduced exercise tolerance, or a return of symptoms that existed before pacemaker implantation.
Call 911 for fainting, severe breathing difficulty, prolonged chest pain, confusion, or other signs of a medical emergency. Do not drive yourself to the hospital after losing consciousness or developing severe symptoms. A pacemaker problem is only one possible explanation, and other heart emergencies must also be ruled out.
How Doctors Decide Between Monitoring and Replacement
Management is based on more than the device’s name. Clinicians consider whether the patient is pacemaker-dependent, the underlying rhythm problem, the presence of heart failure, the type of pacemaker, remaining battery longevity, remote-monitoring reliability, previous alerts, surgical risk, and access to urgent medical care.
Patients at higher risk from Safety Mode who have not received the relevant software update may need a prompt in-person appointment when four years or less of estimated longevity remains. Other patients may continue with standard annual visits, with checks becoming more frequent when the device reaches its one-year-remaining battery indicator.
For some pacemaker-dependent patients with certain extended-life or CRT-P models, limited remaining longevity, no dependable remote monitoring, and a need for wanded telemetry, clinicians must also account for a residual risk that an in-clinic interrogation could itself trigger Safety Mode. Device teams have detailed workflow recommendations for handling these higher-risk situations safely.
This is shared decision-making in its most practical form. The patient brings personal priorities, symptoms, travel limitations, and concerns. The clinician brings interrogation data, procedural experience, and an understanding of the person’s dependence on the device. The best answer is individualized, not copied from an alarming social-media post written in capital letters.
What Pacemaker Generator Replacement Usually Involves
People often call the procedure a “battery change,” but clinicians usually replace the entire pulse generator containing the battery and electronic circuitry. The existing leads may remain in place if testing shows that they are functioning properly.
The physician reopens the pocket beneath the skin, disconnects the old generator, inspects and tests the leads, attaches the replacement generator, and closes the incision. Many replacements are performed as outpatient procedures or require only a brief hospital stay.
A pacemaker-dependent patient may temporarily need additional pacing support while the generator is disconnected. Recovery is often easier than after the first implantation because new leads usually are not placed, although individual experiences vary.
Experiences Patients and Families May Encounter
The following scenarios are composites based on commonly reported clinical situations and are not descriptions of one identifiable patient.
The Recall Letter Arrives
For many patients, the hardest moment is not a symptom but an envelope. A letter arrives containing words such as “urgent,” “battery,” and “serious injury.” The recipient reads the first paragraph, skips to the worst sentence, and understandably wonders whether the pacemaker might stop before dinner.
A more productive next step is to find the device card and call the device clinic. The clinic may already have a list of affected patients and can review the model, serial number, latest transmission, firmware, estimated longevity, and pacing percentage. One person may need an appointment within days, while another may safely wait until a scheduled visit. The same recall notice can lead to different plans because the patients are not interchangeable parts.
The Remote Monitor Suddenly Matters More
Before a recall, a bedside communicator can feel like an odd electronic houseguest that never contributes to the electric bill conversation. After a recall, patients often become much more interested in whether it is connected.
A caregiver may check the power cord, reposition the unit, or call the clinic after noticing a warning light. The device team may confirm that transmissions are arriving normally, request a manual transmission, or schedule an in-person interrogation because the updated firmware cannot be installed remotely.
That interaction can be reassuring, but it may also produce new questions. Does the clinic review data overnight? What happens during travel? Will the monitor work in another country? Patients benefit from writing these questions down rather than relying on memory during a five-minute telephone call fueled by adrenaline.
The In-Clinic Software Visit
During an update appointment, a technician or clinician places a programming wand near the implant or establishes communication with the device. The patient may feel nothing while the system reviews settings, tests the battery, checks the leads, and installs new firmware.
The team may explain that the battery has adequate projected longevity and no evidence of high impedance. In that situation, the plan may be continued monitoring rather than replacement. For someone who arrived expecting immediate surgery, “go home and keep the monitor connected” can sound almost suspiciously uneventful. Uneventful, however, is an excellent result in a cardiology clinic.
When Replacement Becomes the Safer Choice
Another patient may receive a battery alert, experience telemetry disablement, or enter Safety Mode. The clinician then discusses generator replacement, including how urgently it should occur and whether hospitalization is needed.
Patients commonly worry that replacement means repeating the entire original operation. Learning that the existing leads can often remain in place may reduce anxiety. A pacing-dependent patient may require extra precautions, but the procedure is familiar territory for an experienced electrophysiology team.
After replacement, many patients describe relief mixed with irritation: relief that the risk has been addressed, irritation that a device expected to last longer required another procedure. Both reactions are reasonable. A successful outcome does not erase the inconvenience, uncertainty, time away from work, transportation challenges, or stress experienced by family members.
The Caregiver’s Experience
Caregivers often become unofficial project managers. They locate identification cards, charge phones, confirm appointments, organize medications, monitor symptoms, and listen for explanations while the patient processes the emotional weight of the situation.
A simple written plan can help: whom to call during office hours, which symptoms require emergency care, whether remote monitoring is active, when the next interrogation is scheduled, and what firmware or battery findings were documented. Clear instructions transform a frightening recall into a manageable sequence of actions.
Conclusion
The recall involving faulty batteries in heart devices is serious, but it is not a signal for every pacemaker patient to seek immediate surgery. The central problem involves high internal battery impedance in Boston Scientific ACCOLADE-family pacemakers and CRT-P devices. Under higher-power conditions, affected batteries may underpower the system and trigger irreversible Safety Mode.
The practical response is identification, software correction, reliable remote or in-person monitoring, prompt evaluation of symptoms, and individualized replacement decisions. Patients should keep their implant cards accessible, attend every scheduled device check, confirm that remote monitoring is connected, and discuss the SMR6 update with their heart-device clinic.
Medical note: This article provides general educational information and is not a substitute for advice from a cardiologist or electrophysiologist. Patients should not change device settings, disconnect monitoring equipment, or postpone recommended care based on online information. Call 911 for fainting, severe shortness of breath, prolonged chest pain, or other emergency symptoms.
