How TENS Can Affect Different Types of Pacemakers

Living with a pacemaker opens the door to a more active, worry-free life for millions of people. Yet new questions often arise about the safety of everyday therapies—particularly when it comes to electrical pain relief devices like Transcutaneous Electrical Nerve Stimulation (TENS). For those counting on a pacemaker to keep their heart in rhythm, the idea of applying electrical currents elsewhere on their body may sound risky.

But how dangerous is TENS, really? Are all pacemaker types equally vulnerable? What does the latest medical evidence advise? And what can you use for pain relief instead—especially when you want a non-opioid, non-electrical solution?

This in-depth guide unpacks everything patients, caregivers, and clinicians need to know about TENS and pacemakers: from how these devices work, to the subtle interactions between different pacemaker models and electrical currents, to the very best alternatives available today.

Table of Contents

1. Introduction: Pacemakers, Pain, and Modern Dilemmas

2. How Pacemakers Work: A Short Tech & History Lesson

   • Synchronous/Demand Pacemakers

   • Asynchronous/Fixed-Rate Pacemakers

   • Dual-Chamber, Biventricular, and ICD Devices

3. How TENS Works: Mechanisms, Frequencies, and Placement

4. Electromagnetic Interference (EMI): The Core Problem

5. Scientific Evidence: TENS-Pacemaker Interactions by Device Type

   • Synchronous Pacemakers

   • Asynchronous Pacemakers

   • Dual-Chamber and Biventricular Devices

   • Implantable Cardioverter Defibrillators (ICDs)

6. Clinical Case Studies

7. What Influences Risk? (Placement, Frequency, Device Age, Sensitivity)

8. International Guidelines and Manufacturer Recommendations

9. Myths vs. Facts: TENS and Pacemaker Safety

10. Safe Pain Relief Alternatives: Three Proven Approaches

11. Practical Pain Management for Pacemaker Users

12. FAQs

13. Conclusion

1. Introduction: Pacemakers, Pain, and Modern Dilemmas

With nearly 3 million Americans relying on pacemakers—and more than 200,000 new devices implanted every year—cardiac pacing is one of the most successful interventions in modern medicine. But with longer life comes new challenges: orthopedic aches, chronic back pain, arthritis, and musculoskeletal injuries are common in the very population that depends on pacemakers.

The natural question for many: can I safely use popular pain relief methods, such as TENS units, without endangering my heart or device?

2. How Pacemakers Work: A Short Tech & History Lesson

Synchronous (Demand) Pacemakers

By far the most common type in modern medicine. These devices "listen" for natural heart activity via sensors and deliver a pulse only when needed. If a heartbeat is missed or falls below a preset rate, the device steps in.

• Atrial synchronous: focuses on the upper chambers.

• Ventricular synchronous: for main pumping chambers.

• Dual-chamber: coordinates both atrium and ventricle.

Sensitivity to external electrical signals makes these devices more vulnerable to interference.

Asynchronous Pacemakers

Rare today for permanent pacing. These fixed-rate devices do not sense the heart's activity; they simply pace at a preset rate regardless. Often used temporarily during certain surgeries or when sensing is unreliable.

Lack of sensing generally makes them more resistant to outside electrical interference.

Biventricular & Cardiac Resynchronization Devices

Used for heart failure, these pace both ventricles to improve coordination and cardiac output—relying on multi-site sensing.

Implantable Cardioverter Defibrillators (ICDs)

Provide both pacing and rapid, life-saving shocks for dangerous arrhythmias. Their highly sensitive circuitry detects even minimal arrhythmic signals—making them especially prone to electromagnetic interference (EMI).

3. How TENS Works: Mechanisms, Frequencies, and Placement

Transcutaneous Electrical Nerve Stimulation (TENS) uses battery-powered electrodes placed on the skin, typically near the site of pain. The device sends low-voltage electrical pulses to “confuse” or block pain signals traveling along nerve fibers.

• Frequencies: Common settings range from 2–100Hz.

• Current: Usually up to 40mA, but adjustable.

• Placement: Most often over painful areas, joints, or muscle groups—not uncommonly over the neck, back, or even upper chest.

The very currents that relieve pain are what raise safety fears for those with implanted cardiac devices.

4. Electromagnetic Interference (EMI): The Core Problem

Pacemakers and ICDs are designed to respond to minuscule electrical signals coming from the heart. TENS, conversely, introduces an external electrical current that travels through skin, muscle, and tissue.

If TENS pulses mimic the electrical pattern of a heartbeat, a pacemaker might:

• Fail to pace when needed (inhibition)

• Pace at the wrong time (triggering)

• Misinterpret the TENS as lethal arrhythmia (especially ICDs)

• Cause complete device malfunction

The possibility of EMI is the reason most experts and device manufacturers warn against TENS for those with pacemakers or recommend specialist supervision.

5. Scientific Evidence: TENS-Pacemaker Interactions by Device Type

Synchronous (Demand) Pacemakers

Most studies show synchronous pacemakers are at the highest risk of TENS interference. Key findings:

• TENS signals (especially at low frequencies or high currents) can be “read” by the pacemaker as actual cardiac signals, causing the device to withhold pacing when it is actually needed.pmc.ncbi.nlm.nih+1

• Clinical monitoring shows inhibition or mis-pacing in up to 80% of synchronous devices when TENS is applied to the chest, but risk drops if TENS is used on limbs or with rigorous cardiac monitoring.pmc.ncbi.nlm.nih

Asynchronous (Fixed-Rate) Pacemakers

These seldom-used devices (except for special short-term scenarios) lack the sensing function, so they generally do not respond to TENS. Studies confirm that TENS does not block, misfire, or otherwise disrupt asynchronous pacing, regardless of electrode placement.wjgnet+1

Dual-Chamber and Biventricular Devices

Their multi-site sensing can actually increase vulnerability: more leads, more circuits, and more “eyes” open to detecting stray currents. Dual-chamber pacemakers and biventricular devices have been shown in studies to be inhibited or to misfire in response to TENS applied near the chest, with risk proportional to current and proximity.academic.oup+2

Implantable Cardioverter Defibrillators (ICDs)

These lifesaving devices are arguably at greatest risk. Not only can TENS interfere with pacing, but in case studies and trials, TENS signals—especially over the upper body—have caused inappropriate ICD shocks when the device interprets TENS pulses as dangerous arrhythmias. Even modern ICDs with advanced filtering are not immune: “minor and intermittent electromagnetic interference” was detected in 16% of patients in the largest studies, sometimes resulting in noise reversion, pace inhibition, or false arrhythmia detections.academic.oup+1

6. Clinical Case Studies

• A 2023 trial of 107 patients with modern ICDs used TENS over the chest and neck. It found minor EMI in 16%—manifesting as noise, inhibition, or brief asynchrony. Higher currents and thoracic placement increased risk.academic.oup

• Other studies confirm that synchronous and dual-chamber pacemakers may be inhibited or mispaced, especially if TENS is used near the device or at specific low frequencies.academic.oup+1

• Case reports: Multiple ICD shocks have been triggered by TENS therapies applied to the neck, chest, or upper back—even in well-shielded devices.wjgnet

7. What Influences Risk?

Several factors make TENS more or less hazardous for people with pace-keeping devices:academic.oup+2

• Electrode Placement: The closer to the heart or leads, the higher the risk.

• Frequency and Current: Low frequencies (1–6Hz) and higher current increase risk of inhibition or misfiring.

• Lead Configuration: Unipolar leads carry more risk than newer bipolar designs.

• Device Manufacturer and Age: Newer devices tend to have better shielding and algorithms, but are not immune.

• Mode and Sensitivity: Sensitivity settings turned up too high (“listening” for faint signals) make devices more susceptible.

8. International Guidelines and Manufacturer Recommendations

The consensus of major clinical guidelines and pacemaker manufacturers:

• TENS is not recommended for most people with a pacemaker or ICD, particularly if:

  • Device is on a demand/sensing mode

  • Dual-chamber or biventricular system

  • Electrodes to be placed on or near the chest/neck

  • No history of successful, supervised trial

• If TENS must be considered:

  • Always consult a specialist

  • Supervise with real-time ECG and device interrogation

  • Use lowest effective current, place electrodes away from the device/leads (preferably on lower limbs), and avoid thoracic applicationsheart+2

9. Myths vs. Facts: TENS and Pacemaker Safety

Myth: “All TENS units are dangerous for all pacemakers.”
Fact: Asynchronous pacemakers are generally immune, but these are not often used permanently. All sensing/demand devices—including dual-chamber, biventricular, or ICDs—are potentially at risk, particularly with thoracic or high-current applications.pmc.ncbi.nlm.nih+1

Myth: “TENS is always safe on the arm or leg.”
Fact: While limb placements reduce risk, robust trials with large sample sizes are lacking. Clinicians recommend caution—even for peripheral applications—without specialist advice and device monitoring.pmc.ncbi.nlm.nih

Myth: “Modern pacemakers now block all interference.”
Fact: Improvements have reduced risk (e.g., better filtering and shielding), but device malfunction or inappropriate therapy remains a real possibility—especially with higher electrical settings, bad placement, or certain device models.academic.oup+1

Myth: “If you don’t feel anything wrong during TENS, your pacemaker wasn’t affected.”
Fact: Some disruptions are asymptomatic but still place patients at risk of dangerous rhythms or missed pacing.

10. Safe Pain Relief Alternatives: Three Proven Approaches

When TENS is off the table, it’s vital to know what is safe, effective, and doesn’t pose a hazard to your heart or pacemaker.

1. Topical Comfrey Patches

Comfrey root extract is a plant-based remedy validated in multiple randomized clinical trials for reducing pain, swelling, and bruising from musculoskeletal injuries, sprains, and arthritis. In patch form, it’s easy to apply, non-systemic, and has no known interactions with cardiac devices.swordhealth

Try: Comfrey Patches

2. Professional Massage Therapy

Hands-on physical therapy—including Swedish, deep tissue, myofascial release or trigger point massage—can greatly reduce pain, improve flexibility, and support recovery without any electrical or electromagnetic components. Certified therapists can tailor methods for cardiac patients.

Find a therapist near you, or use trusted massage directories.

3. H-Wave® Device Stimulation

The H-Wave® system uses a unique waveform and different frequency range than TENS. Patient and clinician studies suggest more profound pain relief and reduced inflammation, with a different (and usually safer) risk profile for pacemaker users. However, consult your cardiologist before using H-Wave or any electrical device—device and method matter.

Learn more: H-Wave® Device Therapy

11. Practical Pain Management for Pacemaker Users

• Always inform every provider (physicians, physical therapists, acupuncturists) about your pacemaker.

• Any electrical device—including TENS, EMS, and muscle stimulators—should be used only after cardiac device consultation and, ideally, device-specialist supervision.

• For most pain conditions, begin with non-electrical treatments: topical herbal remedies, massage, supervised exercise, heat/cold therapy, physical therapy, acupuncture (without electrical stimulation).

• Keep learning: subscribe to evidence-based pain management newsletters like modernpainrelief.org.

12. Frequently Asked Questions (FAQ)

Can I use TENS on my back or leg if my pacemaker is in my chest?
Some studies suggest that limb applications are lower risk, but due to the variability in devices and human anatomy, no setting is truly guaranteed safe without specialist guidance and in-person device monitoring.academic.oup+1

Can I use EMS (Electrical Muscle Stimulation) instead?
EMS units have a different design and output, but many carry the same EMI risks as TENS—especially when used on or near the torso. Again, always consult your device team.droracle+1

Do microwave ovens, wireless electronics, or massage chairs impact my pacemaker?
These common household devices generally do not cause clinically meaningful interference, but all electrical/magnetic items should be kept at least 6 inches away from the device itself.bostonscientific+1

What about acupuncture with electrical stimulation?
Electroacupuncture may carry similar risks to TENS if applied near the chest or with high currents. Traditional needle-only acupuncture is typically safe.

Will future “leadless” pacemakers be immune?
While leadless designs may reduce some risks, external EMI concerns will remain for all pacemakers that rely on electrical sensing.

13. Conclusion

For anyone with a pacemaker—especially those with modern sensing devices, dual-chamber, biventricular models, or ICDs—TENS therapy is not a safe pain relief option unless cleared and supervised by a device specialist. Asynchronous pacemakers present less risk, but are rare for long-term use.

The safest course: discuss all therapies, especially electrical options, with your cardiac and pain specialists. Non-electrical options like topical comfrey patches (comfreypatches.com/products/comfrey-patches), professional massage, and (with caution and supervision) H-Wave® can effectively manage pain—without compromising your heart’s safety.