HBOT With a Pacemaker, ICD, or Implant: Is It Safe?

If you have a pacemaker, an implantable cardioverter-defibrillator (ICD), or another implanted device, the question of whether you can safely sit inside a pressurized hyperbaric chamber is reasonable and important. The short version is that having an implant does not automatically rule out hyperbaric oxygen therapy (HBOT), but it does add a screening step that a responsible clinic should never skip. This article walks through what the pressure actually does to a device, what the manufacturers and published trials say, and the exact questions that separate a safe treatment from a careless one.

Why an Implant Raises the Question at All

Hyperbaric oxygen therapy works by putting your whole body inside a sealed chamber and raising the pressure well above normal sea-level pressure. Most medical HBOT happens at 2.0 to 2.5 atmospheres absolute (ATA), which is roughly the pressure a scuba diver feels at 33 to 50 feet underwater. While you sit at that pressure, you breathe close to 100% oxygen. The combination dissolves far more oxygen into your blood and tissues than normal breathing ever could.

A pacemaker or ICD is a small sealed electronic device that lives under your skin, usually below the collarbone. It contains a battery, a circuit board, and a housing (the "can") that is built to keep body fluid out. When the chamber pressurizes, that pressure pushes inward on everything inside, including the device. Two separate worries follow from that. First, can the pressure physically crush, deform, or damage the device? Second, can the pressure change how the device behaves while you are inside, for example by altering its pacing rate or its ability to deliver a shock? Both questions have answers, and the answers have gotten better over the past decade.

The reason the worry exists at all is partly historical. For years, many hyperbaric programs simply listed pacemakers and ICDs as a flat "no" on their intake forms, because the early devices were less robust and there was little testing to prove otherwise. Caution made sense when nobody had measured what actually happened. The devices have since been redesigned and stress-tested, and the published record has caught up, so the blanket ban has softened into a verification step. That history is worth knowing, because some clinics still run on the old rule and may turn you away when a phone call to the manufacturer would have cleared you. Knowing the difference between an outdated reflex and a genuine safety limit puts you in a better position to ask the right question.

It helps to understand the broader rules of the chamber too. For a fuller picture of how the pressure cycle works and who should be cautious, see our guide on HBOT contraindications and when it's genuinely dangerous and the companion piece on compression and decompression and what actually happens in HBOT.

The One-Line Answer Clinicians Use

In standard hyperbaric medicine teaching, there is exactly one absolute contraindication to HBOT, and it is not an implanted device. It is an untreated pneumothorax, a collapsed lung with trapped air, because changing the pressure can turn it into a life-threatening tension pneumothorax during the ascent back to surface pressure. Intraocular gas (a gas bubble placed in the eye during certain surgeries) is treated as an absolute bar for anything short of a life-saving emergency. Everything else, including pacemakers and ICDs, falls into the category of relative contraindications, according to the standard reference used in clinical training (StatPearls, HBOT Contraindications).

A relative contraindication does not mean "no." It means "stop, check, and verify before you proceed." For an implanted device, that verification is a specific, concrete step: confirm with the device manufacturer that this exact model has been pressure-tested to at least the treatment pressure the clinic plans to use (StatPearls, Hyperbaric Patient Selection).

What the Pressure Actually Does to a Device

Modern pacemakers and ICDs are sealed, rigid devices, and they hold up to chamber pressure far better than most people assume. The numbers below come from manufacturer testing and the published engineering review, and they explain why a 2.0 to 2.5 ATA treatment sits comfortably inside the safety zone for current devices.

Medtronic, one of the largest device makers, has reported that its implantable pacemakers should operate normally up to roughly 2.5 ATA. Rate-responsive pacing (the feature that speeds your heart rate up when you move) may begin to diminish at pressures above about 3 ATA, and the device itself does not begin to significantly deform until pressures approach 5 ATA (Operation of Implantable Cardiac Devices in Hyperbaric Conditions, IntechOpen). In other words, the standard medical HBOT pressure of 2.0 to 2.5 ATA is below the point where Medtronic devices are expected to behave differently at all.

Boston Scientific has published similar laboratory pressure-test data for its devices. In testing, its EMBLEM subcutaneous ICD generators functioned as designed through more than 300 pressure cycles up to 3.0 ATA, and its RESONATE and ACCOLADE generators functioned through more than 1,000 cycles up to 5.0 ATA. Boston Scientific names 2.5 ATA as the maximum pressure it recommends for hyperbaric chamber therapy and is careful to state that publishing this test data is not an endorsement of HBOT. Either way, the medical treatment range is inside what these devices have survived in the lab.

Here is how the key pressure thresholds line up against everyday treatment pressures.

The takeaway from the table is plain: the gap between a real treatment pressure (about 2.4 ATA at most) and the pressure where a modern device starts to misbehave (3 ATA and up) is a genuine safety margin, not a coin flip.

What the Published Evidence Shows

Engineering specs are reassuring, but they are not the same as watching what happens to real patients and real devices. The evidence here is small but consistent, and it has shifted the field toward greater confidence.

A 2023 laboratory study published in Europace tested 22 explanted ICDs of various brands and models under hyperbaric pressure. The devices were split into two groups: one exposed to a single dive to an absolute pressure of 4000 hPa (about 3.9 ATA) and one exposed to 30 repeated dives at that pressure. Across all of them, the researchers found no mechanical distortion, no inappropriate firing of anti-tachycardia therapy, and no failure of the programmed pacing or shock settings. Their conclusion was that dry hyperbaric exposure appears harmless to ICDs tested outside the body, and that this may justify reconsidering the long-standing idea that an ICD is an absolute bar to emergency HBOT (Guenneugues et al., Europace, 2023, PMID 37208302).

A 2024 report in the Journal of Arrhythmia looked at the patient side. It followed cardiac implantable electronic device (CIED) recipients who actually underwent HBOT within the pressure range specified by their device manufacturers (around 2.5 ATA). It found no impact on device parameters and no abnormal device operation during therapy, and noted that major manufacturers had no case reports of CIED problems tied to HBOT to date (Goto et al., Journal of Arrhythmia, 2024, PMID 39139862).

Honest grading matters here. These are reassuring signals, not a large randomized trial. The Europace work was done on devices outside the body in a dry chamber, and the patient series are small. A dry, explanted device on a test bench is not perfectly identical to a device implanted in living tissue, where the surrounding fluid and the lead wires running to the heart add small variables that a bench test cannot fully reproduce. The patient series, meanwhile, count their subjects in the dozens, not the thousands, which is enough to flag an obvious danger but not enough to rule out a rare one. No regulator or professional society has issued a blanket statement declaring implanted devices universally safe in the chamber, and the manufacturers themselves are careful to publish pressure data without endorsing HBOT.

So what the evidence supports is a clear and useful statement: for current-generation pacemakers and ICDs treated at standard pressures with manufacturer confirmation, there are no reported device failures and a sound mechanistic reason to expect none. What the evidence does not support is skipping the manufacturer check, assuming an old or obscure device is automatically fine, or treating at pressures above the range the device was tested for. The strength of the data is "low-quality but consistent and reassuring," and that is exactly why the manufacturer verification step still belongs in the process rather than being waved away.

The Heart Itself Can Matter More Than the Device

For many patients, the bigger HBOT question is not the hardware but the heart that prompted the implant. People get pacemakers and ICDs for arrhythmias and, in some cases, for heart failure with a weak pump. Heart function deserves its own look before treatment.

Breathing high-pressure oxygen causes blood vessels to tighten, which raises the load the heart pumps against (afterload) and can lower cardiac output. In a heart that is already weak, that shift can, in rare cases, tip someone into fluid backing up in the lungs (flash pulmonary edema). Because of this, congestive heart failure with a left ventricular ejection fraction below about 35% is listed as a relative contraindication, and clinicians are advised to evaluate cardiac function before elective HBOT (StatPearls, Hyperbaric Patient Selection).

The real-world data offers some reassurance for milder cases. A 2024 retrospective cohort study in PLOS One reviewed 23 heart failure patients who underwent elective HBOT, including patients with both preserved and reduced ejection fraction. Most (21 of 23) completed treatment without complications, but two developed symptoms of HBOT-related heart failure exacerbation (pulmonary edema) that were managed and, in one case, required hospital admission. The authors concluded that heart failure patients, including those with preserved ejection fraction, can receive HBOT safely after their heart failure therapy and fluid status are optimized, while noting that the overall evidence base for elective HBOT in heart failure remains limited (Schiavo et al., PLOS One, 2024, PMID 38330042). The practical message: if your device is there because of a weak heart, your ejection fraction and fluid status are part of the safety conversation, separate from the pressure rating of the device.

A Practical Pre-Treatment Checklist

A good clinic handles the implant question with a short, specific process rather than a shrug or a blanket "no." The table below maps what should happen for each common situation.

Notice the difference between elective and emergency care. For wellness or off-label elective HBOT, there is no reason to rush past an unverified device, and the safe move is to delay until the rating is confirmed. For a true emergency like severe carbon monoxide poisoning or gas gangrene, the calculus changes, the published evidence increasingly supports treating, and clinicians weigh the small device risk against a much larger threat to life (StatPearls, HBOT Contraindications).

The single most useful thing you can do before any appointment is bring your device card. Every pacemaker and ICD patient is issued a wallet card at implantation that lists the manufacturer, the exact model name, and the serial number. That card lets the clinic make the manufacturer call in minutes instead of guessing or canceling. If you have lost it, your implanting cardiologist's office can pull the information from your records, and the clinic can also interrogate the device with a programmer to read out the model. Walking in without that information is the most common reason an otherwise eligible patient gets delayed. A second small but real point: tell the clinic about every implant, not just the heart device. Spinal cord stimulators, drug-delivery pumps, cochlear implants, and even some neurostimulators each have their own pressure considerations, and the technician needs the full list to clear you safely.

If you are still in the research phase, our 15 questions to ask before starting hyperbaric oxygen therapy covers the device question alongside the other things a careful patient should raise.

Soft Chambers, Home Use, and Why the Setting Changes the Risk

The implant question interacts with where you get treated. A hospital or accredited outpatient hyperbaric unit has staff who interrogate devices, monitor your heart rhythm during the dive, and follow written protocols if anything looks off. A home soft-shell chamber or a low-pressure "wellness" pod usually has none of that.

At the low pressures of soft chambers (about 1.3 ATA), the mechanical risk to a modern device is essentially nil because that pressure is far below any device threshold. The problem is the surrounding safety system, not the pressure. The FDA has cleared hyperbaric chambers only for specific medical indications and warns that fires and explosions have happened in chambers operated outside accredited facilities, which is why it recommends treatment under a doctor's care at an accredited site. A person with an implant who self-treats at home loses the monitoring, the manufacturer verification, and the trained staff who would catch a problem. The device is unlikely to be the thing that goes wrong, but the absence of oversight is the real hazard. For more on this trade-off, see mild HBOT vs medical HBOT and why 1.3 ATA is controversial.

Alternatives and What "Not a Candidate" Really Means

If a manufacturer cannot confirm your device's pressure rating, or if your cardiac status makes the chamber a poor idea, that is not a dead end. The condition you hoped to treat with HBOT often has other options, and the right next step depends on why you wanted HBOT in the first place.

For a non-healing diabetic foot wound, advanced wound-care centers offer debridement, offloading, specialized dressings, and topical oxygen approaches that do not require pressurizing your whole body. For recovery, performance, or general wellness goals, the evidence behind HBOT is thinner to begin with, and the honest answer is that skipping it costs you little proven benefit. The key is to match the alternative to the actual problem rather than treating HBOT as the only path. A frank look at what else exists is in our overview of the best alternatives to hyperbaric oxygen therapy.

It is also worth separating "my device can't be confirmed" from "I'm not a candidate at all." The first is often solvable with a phone call to the manufacturer or a device interrogation. The second is a clinical judgment that weighs your whole picture. A clinic that says no should be able to tell you which of the two it is and why.

Who This Is For and Who Should Be Cautious

You are likely in a reasonable position to proceed, after proper checks, if you have a current-generation pacemaker or ICD, your clinic confirms the model tolerates the planned pressure, your cardiac function is stable, and you are treating at an accredited facility with monitoring. The published record for devices treated this way shows no failures.

You should be more cautious, and may need to wait or decline, if your device is old or its pressure rating cannot be verified, if you have heart failure with a low ejection fraction, if you have any condition that is itself a contraindication (an untreated pneumothorax, intraocular gas), or if your only available option is an unsupervised home chamber. In every one of those cases, the safe answer is to slow down and get the specific question answered rather than guessing. The recognized clinical indications and the framework for who qualifies are maintained by the field's professional body (UHMS Indications for HBOT), and a broader survey of current research and device safety is available through PubMed's literature on cardiac implantable devices and HBOT.

Frequently Asked Questions

Can I have HBOT if I have a pacemaker?

In most cases yes, but only after a specific check. A pacemaker is a relative contraindication, not an absolute one. Before treatment, the clinic should confirm with the device manufacturer that your exact model has been pressure-tested to at least the treatment pressure they plan to use, which for standard medical HBOT is about 2.0 to 2.5 ATA. Current-generation devices generally clear that bar with room to spare.

Will the chamber pressure damage my ICD or stop it from working?

For modern devices at standard treatment pressures, the evidence says no. Manufacturer testing shows devices operate normally up to about 2.5 ATA, with deformation only appearing near 5 ATA, far above any clinical protocol. A laboratory study of 22 explanted ICDs found no mechanical or functional failures even after repeated dives near 3.9 ATA. The main caveats are very old devices and pressures above 3 ATA, which are not used in routine therapy.

What's the difference between a relative and an absolute contraindication?

An absolute contraindication means HBOT should not be done, period; in standard teaching the only true one is an untreated collapsed lung (pneumothorax). A relative contraindication, which is where pacemakers and implants sit, means you can usually still be treated but only after specific precautions, such as verifying the device's pressure rating and arranging monitoring. The distinction is the difference between "never" and "check first."

Does it matter if my pacemaker is also for heart failure?

Yes, but the concern shifts from the device to the heart. Breathing high-pressure oxygen tightens blood vessels and can raise the load on a weak heart, so heart failure with an ejection fraction below about 35% is treated as a relative contraindication on its own. If your device is there because of a weak pump, expect your clinic to evaluate your cardiac function and fluid status, not just the device's pressure rating.

Is it safe to use a home or soft-shell chamber with an implant?

The low pressure of a soft chamber (around 1.3 ATA) poses essentially no mechanical risk to a modern device, but the setting is the problem. Home chambers lack the device interrogation, heart-rhythm monitoring, and trained staff that a hospital provides, and the FDA warns that fires have occurred in chambers operated outside accredited facilities. With an implant and an underlying heart condition, that loss of oversight is the real hazard, so an accredited medical facility is the safer choice.

This article is for general education and is not medical advice. Decisions about hyperbaric oxygen therapy with a pacemaker, ICD, or any implanted device should be made with your physician and the hyperbaric medical team, who can verify your specific device and health status.