Can You Have ESWL With a Pacemaker or During Pregnancy? When Shock Waves Are Avoided or Adapted

The urologist has just said the word “lithotripsy,” and the patient in the chair reaches, almost without thinking, for the small firm bump under the skin below his left collarbone. He has had the pacemaker for six years. He barely notices it anymore. Now he is wondering whether a machine that shatters stones with sound could also confuse a machine that keeps his heart in rhythm.

Two rooms down, a woman who is 22 weeks pregnant is asking a different version of the same question. Her flank pain has a name now, a small stone in the ureter, and she wants the least invasive fix. She has read that ESWL is non-surgical. Why, then, is her care team steering her away from it?

ESWL with pacemaker questions and ESWL in pregnancy questions get lumped together online, but the answers pull in opposite directions. One is usually a matter of planning. The other is a firm no. Here is what the evidence actually says about both.

How ESWL actually works: shock waves aimed at a stone, not at you

Extracorporeal shock wave lithotripsy, shortened to ESWL, is a way of breaking a kidney or ureteral stone into small fragments using pressure waves generated outside the body. “Extracorporeal” simply means “outside the body.” No cut is made.

The patient lies on a table, sometimes on a soft water-filled cushion. The team uses X-ray or ultrasound to locate the stone precisely, then lines the stone up with the focal point of the shock wave source. Each pulse travels through skin, fat and muscle with very little effect on those soft tissues, because they have a density close to water. When the wave hits the stone, which is far denser, the sudden change in density creates stress at the stone’s surface. Repeated pulses open cracks, and the stone crumbles into pieces small enough to travel down the ureter and out in the urine.

A session typically lasts about 45 minutes to an hour, according to MedlinePlus, and is usually done with sedation or a light general anesthetic so the patient stays still and comfortable. The sound is a rhythmic thump, not unlike someone tapping a table.

Two details matter for the questions in this article. First, the shock waves are mechanical energy, not electrical current, but the machine that creates them is electrical and the waves themselves can deliver a physical jolt to anything in or near the focal zone. Second, many lithotripters are timed to the patient’s heartbeat, firing only during a safe part of the cardiac cycle. That timing system is where a pacemaker enters the conversation.

Can you have ESWL with a pacemaker? The honest answer is usually yes, with preparation

For decades, an implanted pacemaker appeared on lists of reasons not to do ESWL. The concern was straightforward: a device designed to sense and pace the heart electrically might misread the shock waves, the machine’s electromagnetic field, or both. Early case reports described pacemakers switching into backup modes or generator casings being damaged when they sat close to the treatment zone.

Modern practice has shifted. The American Heart Association lists extracorporeal shock wave lithotripsy among medical procedures that can interfere with pacemakers and implantable defibrillators, but it frames the issue as something to discuss with the cardiologist and manage, not as a blanket prohibition. Most contemporary devices are shielded against the kind of interference a lithotripter produces, and the pulse generator in the chest sits far from a kidney.

So the realistic answer to “can you have ESWL with a pacemaker” is: often yes, but only after the urology and cardiology teams have looked at the specific device, where it is implanted, how dependent the patient is on it, and whether it has features that need temporary adjustment. The decision is individual and rests with those clinicians.

The situations that still give teams pause are a generator implanted in the abdomen rather than the chest, an implantable cardioverter-defibrillator (ICD) rather than a simple pacemaker, and a patient whose heart has no reliable rhythm of its own without the device. None of these automatically rules out treatment, but each raises the level of planning and monitoring required, and in some cases a different stone treatment is simpler and safer.

Why a pacemaker and a shock wave can interfere with each other

A pacemaker has two jobs: it listens for the heart’s own electrical signals through its leads, and it fires a small pulse when the heart is too slow. Both jobs can be disturbed by an ESWL machine, for different reasons.

The first problem is misreading. Shock waves striking the body create mechanical vibration, and some lithotripters generate electromagnetic noise when they discharge. A pacemaker that mistakes this noise for a heartbeat may stop pacing when it should, a phenomenon called inhibition. One that mistakes noise for a dangerous rhythm, in the case of an ICD, may deliver an unnecessary shock. Devices with rate-response features, which speed up pacing when they detect body movement or vibration, can also be fooled by the rhythmic pounding of the treatment.

The second problem is physical damage. If the shock wave focal zone passes close to the generator itself, the pressure pulse can damage the electronics or the sealed casing. This is why abdominally placed generators, which sit closer to the kidneys, carry more risk than the usual chest placement.

The third issue runs the other way. Many lithotripters use the patient’s electrocardiogram to time each shock to the heart’s refractory period, the brief window when the heart cannot be triggered into an abnormal beat. A paced rhythm has a slightly different electrical signature than a natural one. Teams need to confirm the machine is reading the paced beats correctly, or switch to a fixed firing rate under close monitoring.

Each of these mechanisms is manageable when it is anticipated. The danger lies in not knowing a device is there, which is why the pre-procedure history matters so much.

Is lithotripsy safe for heart patients more broadly?

Pacemakers are only one part of the heart-health picture. People with coronary stents, prior heart attacks, heart failure, atrial fibrillation or valve disease ask whether ESWL adds risk, and the answer depends less on the shock waves than on what surrounds them.

The shock waves themselves are not cardiotoxic. A coronary stent is a metal mesh far from the treatment zone and is not affected. A repaired or replaced valve is likewise well outside the focal area. The cardiac questions that matter are the same ones asked before any procedure requiring sedation or anesthesia: how stable is the heart rhythm, how well is the heart pumping, and can the patient safely lie flat for an hour?

Anticoagulation is the issue that most often changes plans. ESWL causes small tears in kidney tissue, and some bruising or bleeding around the kidney is expected. In someone taking a blood thinner, that bleeding can be more significant. MedlinePlus and Mayo Clinic both list bleeding disorders and uncontrolled anticoagulation among the reasons ESWL may be avoided. Many heart patients take anticoagulants or antiplatelet drugs for good reason, such as a recent stent or atrial fibrillation, and stopping them carries its own hazards.

The prescribing cardiologist, not the urologist alone, decides whether a medicine can be paused, for how long, and whether a bridging plan is needed. Sometimes the safer route is a treatment that does not depend on stopping the medicine at all, such as ureteroscopy with laser fragmentation. Arrhythmias during ESWL are uncommon and usually brief, but continuous rhythm monitoring is standard for anyone with known heart disease.

What happens on the day when a pacemaker is in place

Planning usually begins well before the treatment room. The urology team asks for the device type, manufacturer, model, implant date and the location of the generator. A device interrogation, meaning a check of the pacemaker’s settings and battery using a bedside programmer, is often arranged in the days beforehand to document how the device is behaving.

On the day itself, several safeguards are typical:

• Continuous electrocardiogram monitoring throughout, watched by someone who can recognize pacing failure or noise.
• Temporary reprogramming for selected devices. Rate-response features may be switched off so vibration does not drive the heart rate up. For ICDs, the shock-delivering function is often suspended for the duration, with external defibrillation available.
• Confirmation that the shock wave focal point is well away from the generator, particularly if the device sits in the abdomen.
• A pulse oximeter and blood pressure monitoring as part of routine sedation care.

Cardiology or a device technician may be present or on call. After the last shock, the device is interrogated again to confirm that settings are back to normal and nothing has changed unexpectedly.

The patient experience is largely the same as for anyone else: arriving fasted, receiving sedation, lying still while the machine works, and resting afterward until fully awake. The extra layer is invisible from the table but real in the planning notes. Anyone with a pacemaker who is scheduled for ESWL and has not been asked about the device should raise it before the appointment, not on the day.

Why lithotripsy during pregnancy is avoided

Here the answer changes completely. Pregnancy is listed by MedlinePlus, Mayo Clinic and Cleveland Clinic as a reason not to perform ESWL. Unlike the pacemaker question, this is not a matter of adjusting settings.

Three concerns drive the decision. The first is the shock wave itself. The focal zone for a lower ureteral stone sits close to the pelvis, and the effect of repeated pressure pulses on a developing fetus, the placenta and the uterus has never been shown to be safe. Animal data and the physics of the treatment are enough for guideline bodies to treat it as unacceptable.

The second is imaging. ESWL relies on fluoroscopy, a form of continuous X-ray, to target the stone. Pregnancy calls for minimizing ionizing radiation, and while ultrasound-only targeting exists, it does not remove the first concern.

The third is anesthesia and positioning. Lying flat for an hour under sedation in the second or third trimester can reduce blood flow through the large vein returning to the heart, and it exposes the fetus to anesthetic drugs when alternatives are available.

None of this means a pregnant patient with a stone is stuck. Kidney stones in pregnancy are managed conservatively first, with hydration, pain control chosen for pregnancy, and watchful waiting, since many stones pass on their own. If the stone will not move, causes infection, or blocks the kidney, options include a ureteral stent (a thin tube holding the ureter open), a nephrostomy tube draining the kidney through the back, or ureteroscopy with a fine scope. Timing and choice belong to the obstetric and urology teams working together.

What are the contraindications for shockwave lithotripsy? A plain-language table

“Contraindication” is the medical word for a reason a treatment should not be given. Some are absolute, meaning the treatment is not offered. Others are relative, meaning it may still be appropriate once the concern is addressed. The following table summarizes the situations that appear consistently across MedlinePlus, Mayo Clinic, Cleveland Clinic and NHS guidance.

Situation	Usual status	Why it matters
Pregnancy	Absolute	Shock waves and X-ray near the fetus; other treatments used
Untreated urinary infection	Absolute until treated	Fragmenting an infected stone can spread bacteria into the blood
Uncontrolled bleeding disorder or anticoagulation	Relative	Kidney bruising and bleeding are expected effects
Pacemaker or ICD	Relative	Interference and timing issues; managed with device check and monitoring
Aortic or renal artery aneurysm near the stone	Relative to absolute	Shock waves could stress a weakened vessel wall
Obstruction below the stone	Relative	Fragments have nowhere to go
Very large or very hard stones	Relative	Poorer fragmentation; other methods often preferred
Uncontrolled high blood pressure	Relative	Raises bleeding risk during treatment

Body habitus deserves a mention without judgment. Shock waves lose energy over distance, and when the skin-to-stone distance is long, fragmentation is less effective and targeting is harder. That is a physics problem, not a personal one, and it is one reason ureteroscopy is sometimes suggested instead.

Stone size is the most common practical limit. NHS guidance describes ESWL as suitable for stones up to about 2 cm, with larger stones usually directed to other approaches.

Who ESWL is usually for, and who is usually asked to wait

The ideal ESWL candidate has a single stone in the kidney or upper ureter, under roughly 2 cm across, made of a material that shatters well, with a clear path below it for fragments to leave. Stones of calcium oxalate dihydrate and uric acid tend to break easily; cystine stones and some calcium oxalate monohydrate stones are notoriously stubborn, and a CT scan can sometimes predict this from the stone’s density.

Because the treatment needs no incision and is done as a day case, it appeals to people who want to avoid a general anesthetic or a scope, and to those for whom a hospital stay is difficult. Children with kidney stones are also treated with ESWL, with equipment and energy adjusted for their size.

Those usually asked to wait, rather than told no, include:

• Anyone with a urinary infection, until it has been treated and urine cultures are clear.
• People on anticoagulants, until the prescribing clinician has advised whether pausing is safe.
• Patients with uncontrolled blood pressure, until it is better managed.
• Pacemaker or ICD patients, until the device check and cardiology input are complete.

Sometimes waiting changes the plan altogether. A stone that has not moved in several weeks despite good hydration, a kidney that is becoming blocked, or pain that cannot be managed at home may push the team toward ureteroscopy instead, because it treats the stone in a single visit without depending on fragments passing later.

For pregnant patients, “wait” often means waiting until after delivery for definitive stone treatment, with a temporary drain or stent if the kidney needs protecting in the meantime. The urologist and obstetrician set that timing together.

What the alternatives look like when shock waves are off the table

When ESWL is not appropriate, three main routes remain, each with a different balance of invasiveness and certainty.

Ureteroscopy involves passing a very thin, flexible telescope through the urethra and bladder and up the ureter to the stone, with no external cut. A laser fiber breaks the stone into dust or small pieces, which can be removed with a tiny basket or left to pass. It works on stones that are too hard for shock waves, on stones low in the ureter, and in people who cannot stop blood thinners, because bleeding risk is lower than with ESWL. A general anesthetic is usual, and a temporary stent is often left in for a few days. For pregnant patients who need definitive treatment, ureteroscopy is generally the preferred active option.

Percutaneous nephrolithotomy, usually shortened to PCNL, uses a small incision in the back to reach the kidney directly. It is reserved for large or complex stones, typically those over 2 cm or filling the kidney’s collecting system, according to Mayo Clinic. It requires a hospital stay and carries more bleeding risk, so it is not a first choice for the situations discussed here.

Drainage without stone removal is the third route. A ureteral stent placed from below, or a nephrostomy tube placed through the back under local anesthetic, relieves the blockage and buys time. In pregnancy this is often the bridge to treatment after delivery.

Observation is a legitimate fourth option for small stones without infection or obstruction. Many stones under a few millimeters pass on their own with time and fluids, and the team may suggest a period of watching with follow-up imaging before committing to any procedure.

What the days and weeks after ESWL usually look like

The first day is about waking up and passing urine. Most people go home the same day and can return to ordinary activity within one to two days, according to MedlinePlus. Blood in the urine is expected, often for a day or two, sometimes longer, and it typically fades from pink to clear. Bruising over the flank where the shock waves entered is common and looks alarming for the amount of discomfort it causes.

The following one to two weeks are when fragments move. This is the part many people are not warned about clearly: fragmenting a stone does not remove it. The pieces still have to travel down the ureter, and each one can cause a wave of colicky pain as it goes. Pain medicine and plenty of fluids are the usual advice, along with straining urine so fragments can be caught for analysis. Knowing the stone type guides prevention later.

MedlinePlus notes that fragments may continue to pass for up to four to eight weeks, and a follow-up X-ray or ultrasound is usually arranged to confirm the kidney is clear. If fragments remain, a second ESWL session or a different treatment may be discussed.

For pacemaker patients, the recovery timeline is the same as for anyone else. The device has usually been interrogated before leaving the treatment area, and no special restrictions apply afterward. It is reasonable to ask whether an extra device check is wanted at the next routine cardiology visit, though this is a matter of local practice rather than a universal requirement.

Not everyone follows this arc. Some pass a handful of gritty fragments and feel fine within days; others have a slower, more uncomfortable few weeks. Both are within the expected range.

What people often get wrong about ESWL, pacemakers and pregnancy

“A pacemaker means ESWL is impossible.” This was closer to true a generation ago and persists on older websites. Current AHA guidance lists ESWL as a procedure that can interfere with cardiac devices and should be discussed with the cardiologist, which is different from forbidding it. Most chest-implanted pacemakers can be safely managed through treatment with monitoring and, where needed, temporary reprogramming.

“Shock waves are electrical, so they will shock the pacemaker.” The waves are pressure waves, not current. The interference risk comes from electromagnetic noise from the machine, from vibration fooling movement sensors, and from timing mismatches, all of which are addressed in planning.

“ESWL is non-invasive, so it must be fine in pregnancy.” Non-invasive describes the skin, not the fetus. Every major source lists pregnancy as a reason not to perform ESWL, and there is no adjustment that makes it acceptable.

“A pacemaker can improve kidney function.” A pacemaker treats a slow or unreliable heart rhythm. Where a very slow heart rate was reducing blood flow to the kidneys, restoring a normal rate can help the kidneys receive the perfusion they need, but the device does not treat kidney disease and is never implanted for that purpose. Anyone hoping a pacemaker will fix declining kidney numbers should raise the question directly with their nephrologist and cardiologist.

“Once the stone is broken, it is gone.” Fragments still have to pass, and that process can take weeks and cause real pain. Preparation for this stage prevents a great deal of anxiety.

“Lithotripsy damages the kidney permanently.” Temporary bruising is expected. The long-term relationship between ESWL and blood pressure or kidney function has been studied for decades without a clear causal link being established, and current guidance does not list this as a reason to avoid treatment.

Shockwave therapy with a pacemaker for tendons and heel pain: ESWT is not ESWL

Search engines blur two very different treatments because their names differ by one letter. ESWL, the subject of this article, breaks kidney stones using focused, high-energy shock waves under anesthesia. ESWT, extracorporeal shock wave therapy, uses much lower-energy pulses applied to tendons, the heel or other musculoskeletal sites to stimulate healing in conditions such as plantar fasciitis and chronic tendinopathy.

The energy levels and equipment are not comparable. An ESWT hand-held applicator delivers a small fraction of the pressure a lithotripter aims at a stone, and treatment happens in a clinic room without sedation. Even so, most ESWT device manuals list a pacemaker or ICD as a precaution, and physiotherapy clinics commonly ask about cardiac devices before treating.

The evidence on ESWT itself is mixed. Systematic reviews suggest a modest benefit for plantar heel pain and some tendon conditions in selected patients, but study quality varies and results are inconsistent across sites and protocols. It is not established as effective for every condition marketed for it, and it should not be presented that way.

For someone with a pacemaker considering ESWT, the sensible steps are the same as for ESWL, scaled down: tell the therapist about the device, ask whether the manufacturer of the applicator lists cardiac devices as a contraindication, and check with the cardiology team if there is any doubt. Treatment sites far from the chest, such as the heel, pose far less concern than sites near the generator or its leads, but that judgment belongs to the clinicians involved, not to a search result.

If the question that brought you here was about heel pain rather than kidney stones, the pregnancy section also does not apply in the same way; ESWT and pregnancy have their own, separate cautions.

Questions to ask your care team before ESWL

A good consultation leaves room for questions, and the ones below are worth writing down beforehand. Not every question will apply to every person.

About the stone and the plan:

• How large is the stone, where exactly is it, and what does its density on the scan suggest about how well it will fragment?
• Why is ESWL preferred over ureteroscopy for me, and what would change that recommendation?
• How likely is it that a second session or a different procedure will be needed, based on stones like mine?

About a pacemaker or ICD:

• Has my device type and location been reviewed, and does anything about it change the plan?
• Will the device be checked before and after, and will anyone from cardiology be involved on the day?
• Do any settings need to be changed temporarily, and who will restore them?

About medicines:

• Should any of my regular medicines, especially blood thinners, be paused, and who makes that call?
• What pain relief is planned for the days afterward, and what should I avoid?

About pregnancy, when relevant:

• What is the plan for managing the stone until delivery, and what would make you act sooner?
• Who coordinates between obstetrics and urology if something changes?

About recovery:

• What symptoms are expected, which ones should prompt a call, and when is the follow-up imaging?
• Should I strain my urine, and what happens to fragments I collect?

Bringing a list is not a sign of distrust. Clinicians generally welcome patients who understand the trade-offs, because informed patients notice problems earlier and follow plans more closely.

When to call your doctor after ESWL

Some discomfort, pink urine and flank bruising are part of the expected picture. A few signs are not, and they call for prompt contact with the treating team or emergency care.

Seek urgent care for any of the following:

• Fever, shaking chills or feeling generally unwell. Fragmenting a stone can release bacteria, and infection behind a blocked ureter can progress quickly.
• Pain that is severe and not relieved by the medicine you were given, or pain that keeps worsening rather than coming in waves that settle.
• Heavy bleeding: urine that stays deep red or contains clots after the first day or two, or bleeding that increases rather than fades.
• Inability to pass urine, or passing only very small amounts despite drinking.
• Persistent vomiting that prevents you keeping fluids down.
• Dizziness, faintness, or a racing or irregular heartbeat, especially for anyone with a pacemaker, ICD or known heart disease.

For pacemaker and ICD patients specifically, any sensation of the device behaving differently, unexplained palpitations, shocks from an ICD, or a recurrence of the symptoms the device was implanted to prevent should be reported the same day to the cardiology team, even if the urology team has already been informed.

During pregnancy, flank pain with fever, reduced fetal movement, contractions, vaginal bleeding or leaking fluid needs immediate obstetric assessment regardless of what stone treatment has or has not taken place.

When in doubt, call. Urology teams would far rather hear about a symptom that turns out to be nothing than learn about an infection or a blocked kidney a day late. Every decision about further imaging, drainage or additional treatment rests with the clinicians who know your case.

Frequently asked questions

Can you do shockwave therapy if you have a pacemaker?

Often yes, but only after cardiology review. For kidney stone lithotripsy, the device is checked beforehand, certain features such as rate response may be switched off, the heart rhythm is monitored throughout, and the shock wave focus is kept well away from the generator. For low-energy ESWT used on tendons and heels, most device manufacturers list pacemakers as a precaution, so the therapist should be told and the cardiology team consulted if there is any doubt.

Is lithotripsy safe for heart patients?

The shock waves themselves do not harm the heart, coronary stents or heart valves. The real issues are sedation tolerance, rhythm stability and blood thinners, because ESWL causes kidney bruising and bleeding. Whether an anticoagulant can be paused is decided by the prescribing cardiologist, and when it cannot, ureteroscopy is often chosen instead because its bleeding risk is lower. Continuous rhythm monitoring during treatment is routine for anyone with known heart disease.

What are the contraindications for shockwave lithotripsy?

Pregnancy and untreated urinary infection are the firm ones. Relative reasons to delay or choose another treatment include bleeding disorders or uncontrolled anticoagulation, a pacemaker or ICD that has not been reviewed, an aneurysm near the stone, an obstruction below the stone, uncontrolled high blood pressure, and stones that are very large or very hard. Each relative contraindication may be resolved with preparation, and the final decision sits with the treating team.

Can a pacemaker improve kidney function?

Not directly. A pacemaker corrects a heart rhythm that is too slow or unreliable. If a very slow heart rate was reducing blood flow to the kidneys, restoring a normal rate can help them receive adequate perfusion, which may show up as steadier kidney blood tests. The device does not treat kidney disease and is never implanted for that reason. Questions about declining kidney function belong with a nephrologist alongside the cardiology team.

Why is lithotripsy during pregnancy not done?

Because the effect of focused shock waves on the fetus, placenta and uterus has never been shown to be safe, and the X-ray guidance used for targeting adds radiation exposure. Lying flat under sedation for an hour in later pregnancy also carries risks when alternatives exist. Stones in pregnancy are managed with fluids, pregnancy-safe pain control and watchful waiting first, then a stent, drainage tube or ureteroscopy if the kidney needs protecting.

Does a pacemaker in the abdomen change the ESWL decision?

It raises the level of caution considerably. Most pacemakers sit in the upper chest, far from the kidneys, but an abdominally placed generator can lie close enough to the shock wave focal zone to risk physical damage to the device casing or electronics. Teams generally treat this as a stronger reason to consider ureteroscopy or another approach, and the cardiology and urology teams decide together based on the exact device position.

Will the ESWL machine reprogram or reset my pacemaker?

Modern devices are shielded, and permanent resets are rare when precautions are followed. The more common concern is temporary misbehavior during the session, such as pacing being inhibited by noise or the rate being driven up by vibration sensors. That is why the device is checked before treatment, monitored during it, and interrogated again afterward to confirm that all settings are unchanged. Report any new palpitations or symptoms to cardiology promptly.

How long after ESWL do the stone fragments take to pass?

Most people return to normal activities within one to two days, according to MedlinePlus, but fragments can keep passing for up to four to eight weeks. During that time, waves of colicky pain and intermittent blood in the urine are expected. A follow-up X-ray or ultrasound is usually arranged to confirm the kidney is clear, and a second session or a different procedure may be discussed if pieces remain.

Is ESWT the same as ESWL?

No. ESWL breaks kidney stones with focused high-energy shock waves under sedation or anesthesia. ESWT uses far lower-energy pulses on tendons, the heel and other musculoskeletal sites to encourage healing, without anesthesia. The evidence for ESWT is mixed and varies by condition. Both carry pacemaker precautions, though the risk profile differs greatly, and ESWT does not share the same absolute contraindication in pregnancy that applies to ESWL.

Can I have ESWL if I take blood thinners for my heart?

Sometimes, but not without a plan. ESWL causes bleeding within and around the kidney, so uncontrolled anticoagulation is a recognized reason to avoid it. The prescribing cardiologist decides whether the medicine can be paused safely and for how long, weighing the reason it was started. When pausing is too risky, such as after a recent coronary stent, ureteroscopy is often chosen instead. Never stop a blood thinner on your own before a procedure.

References

• MedlinePlus: Lithotripsy
• NHS: Kidney stones, Treatment
• MedlinePlus: Pacemakers and Implantable Defibrillators

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.