What Happens If You Need a Pacemaker and Don’t Get One?

Skipping a pacemaker when your doctor recommends one exposes you to a cascade of worsening problems, from debilitating fainting spells to heart failure and, in some cases, sudden death. The specific risks depend on why the pacemaker was recommended in the first place, but the long-term data for untreated heart block and sick sinus syndrome paint a consistent picture: the heart’s electrical system rarely fixes itself, and the consequences of leaving it uncorrected accumulate over months and years.

The Electrical Problems a Pacemaker Fixes

A pacemaker is essentially a tiny battery-powered device that sends electrical pulses to keep your heart beating at a reliable pace. It gets recommended when the heart’s natural electrical signaling goes wrong in ways that slow the heartbeat dangerously or make it unpredictable. The two most common reasons are heart block and sick sinus syndrome.

In heart block, the electrical signal that starts each heartbeat in the upper chambers of the heart gets delayed or completely blocked before reaching the lower chambers. In the most severe form, called complete or third-degree heart block, the upper and lower chambers beat independently of each other. The lower chambers fall back on their own much slower rhythm, sometimes dropping below 40 beats per minute. In sick sinus syndrome, the heart’s natural pacemaker node fires too slowly, pauses for dangerously long stretches, or alternates between abnormally slow and fast rhythms. Both conditions starve the brain and body of adequate blood flow.

Fainting, Falls, and the Risk of Sudden Death

The most immediate danger of going without a pacemaker is syncope, the medical term for fainting. When the heart rate drops low enough or pauses long enough, blood pressure falls and the brain loses oxygen. You black out, sometimes with no warning at all. A long-term study of 101 patients with complete heart block or arrhythmic syncope who never received a pacemaker found that survival was substantially lower when heart block was combined with fainting episodes than in patients whose heart block was asymptomatic.¹ Among the 68 patients with complete heart block, about two-thirds were still alive at one year and roughly a third at five years.

Fainting is not just uncomfortable or embarrassing. It can kill. A study of adults with congenital complete heart block found that fainting episodes (called Stokes-Adams attacks) occurred in 27 patients, and in eight of those cases the outcome was fatal. The most unsettling detail: in six of those eight deaths, the very first fainting episode was the one that killed them.² That finding is the reason cardiologists often recommend pacemakers even for people who feel fine. The first blackout can come without any prior symptoms, and it may not give you a second chance.

Syncope in the context of cardiac disease is treated as a medical emergency precisely because the prognosis depends heavily on the underlying heart condition. A fainting spell from dehydration is very different from one caused by a failing electrical system, and immediate risk assessment is standard practice whenever cardiac syncope is suspected.³

Even when fainting does not end in death, the injuries from falls can be devastating. Older adults who lose consciousness while standing or walking often sustain hip fractures, head injuries, or broken bones. If fainting happens while climbing stairs, driving, or operating equipment, the danger extends well beyond the person’s own body.

How the Heart Weakens Without Pacing

Beyond the acute crisis of a faint or a cardiac arrest, a chronically slow heart rate quietly damages the heart muscle itself. When the heart beats too slowly for too long, the chambers stretch and weaken in a condition known as bradycardia-induced cardiomyopathy. The heart has to push harder and hold more blood with each beat to compensate for fewer beats per minute, and over time this extra workload causes the chambers to enlarge and the walls to lose pumping strength. The result is heart failure: fluid builds up in the lungs and legs, exercise tolerance drops, and ordinary activities become exhausting.

The encouraging piece of this story is that the damage is often reversible once the heart rate is restored to normal with pacing. When the underlying slow rhythm is corrected, the enlarged chambers can shrink back and pumping function can improve substantially.⁴ But the longer you wait, the less fully the heart may recover. And if pacing never happens, the trajectory tends to be progressive heart failure with all of its downstream consequences.

For people with sick sinus syndrome who go untreated, the numbers are bleak. A study tracking 35 patients with untreated sick sinus syndrome found that roughly 57 percent experienced cardiovascular events requiring treatment during follow-up. These events included syncope, overt heart failure, chronic atrial fibrillation, and poorly tolerated episodes of fast irregular rhythms. The rate of these events climbed to about 63 percent by four years.⁵ So while roughly four out of ten patients followed a relatively benign course, the majority did not.

Stroke Risk Tied to Rhythm Problems

One of the less intuitive consequences of forgoing a pacemaker involves stroke. Sick sinus syndrome frequently coexists with atrial fibrillation, a chaotic rhythm in the upper heart chambers that allows blood to pool and form clots. Those clots can travel to the brain and cause a stroke. A large study found that patients with atrial fibrillation who also had sick sinus syndrome experienced a stroke rate of about 4 percent per year, compared to roughly 3 percent per year in atrial fibrillation patients without sick sinus syndrome. After adjusting for other risk factors, sick sinus syndrome was linked to a 23 percent higher risk of stroke.⁶

The stroke risk was especially pronounced in patients who otherwise seemed to be at low risk based on their age and other health conditions. In that group, the presence of sick sinus syndrome roughly doubled the likelihood of stroke. This is one of those findings that changes the calculus for patients who think they can safely wait because they feel fine and have no other major health problems. The electrical dysfunction itself, independent of other risk factors, appears to raise stroke risk.

Even Short Delays Carry Measurable Risk

Some people accept that they need a pacemaker in principle but face delays in getting one, whether because of hospital scheduling, diagnostic uncertainty, or personal hesitation. Research on this question reveals that even short waits are not benign. A study examining patients already scheduled for pacemaker implantation found that those who waited more than one day experienced adverse events about 37 percent of the time, compared to roughly 20 percent in patients who received their device within a day.⁷

Patients with complete heart block were particularly vulnerable during the waiting period, with serious adverse events like syncope, cardiac arrest, dangerous fast rhythms, or death occurring in about 17 percent, compared to roughly 7 percent for other diagnoses. Infection risk also climbed with longer delays: after six days of waiting, about 23 percent of patients developed an infection, compared to roughly 4 percent in those who waited six days or fewer. These numbers underscore that “I’ll get to it eventually” is not a low-risk strategy. Every day without the device is a day exposed to the very problems the device is designed to prevent.

Congenital Heart Block in Children and Young Adults

Not everyone who needs a pacemaker is elderly. Some people are born with complete heart block, a condition in which the heart’s electrical wiring never formed properly. For decades, there was a widespread belief that congenital complete heart block was relatively benign if the person felt well and maintained a reasonable resting heart rate. That belief has been largely revised.

Research into the natural history of congenital heart block has shown that the risk of heart failure, syncope, and sudden death exists at any age, including before birth. The escape rhythm that keeps the heart going tends to slow over the years, and the heart gradually enlarges from the extra workload. Pacing is recommended for all patients older than 15 with congenital complete heart block, and earlier intervention is warranted if there are signs of fainting, rates slower than the median for the person’s age, or changes in heart valve function.⁸

The adult study cited earlier found that prophylactic pacemaker placement was recommended even for symptom-free adults with congenital complete heart block because of the high rate of unpredictable first-time fainting episodes and the significant mortality from those first events.² For young adults who feel perfectly healthy, this can be a hard recommendation to accept. But the evidence is clear that “feeling fine” is not a reliable indicator of safety in this condition.

When a Pacemaker Might Not Be Needed

Not every episode of heart block requires permanent pacing. Some causes are temporary and reversible. One well-documented example is Lyme carditis, in which the bacterial infection responsible for Lyme disease inflames the heart’s conduction system and causes heart block that can be severe. In these cases, antibiotic treatment often resolves the electrical abnormality entirely, and a permanent pacemaker is unnecessary. A temporary pacemaker may be used to bridge the gap while antibiotics take effect.⁹

Other reversible causes include medication effects (certain heart drugs and sedatives can slow conduction), electrolyte imbalances like dangerously high potassium, and inflammation from a recent heart attack that resolves as the tissue heals. In all these cases, the correct approach is to treat the underlying cause and watch whether the conduction problem clears. The key distinction is between a transient insult to the electrical system and a permanent structural defect. If the problem is structural or degenerative, waiting for it to resolve is waiting for something that will not happen.

Specific Conditions That Raise the Stakes

Certain underlying diseases make the consequences of skipping a pacemaker more severe. Cardiac sarcoidosis, a condition in which inflammatory clumps form in the heart tissue, is one of the most sobering examples. Patients with cardiac sarcoidosis whose first cardiac symptom is heart block face a very high risk of developing life-threatening fast rhythms even after the block is treated. A study of this population found that the patients who died suddenly were specifically those who lacked an implantable defibrillator.¹⁰ In conditions like this, the pacemaker (or a combined pacemaker-defibrillator device) is not just managing a slow heartbeat. It is preventing sudden cardiac death from a rhythm that could turn lethal at any moment.

Ischemic heart disease, diabetes, and hypertension also worsen the outlook for people with untreated heart block. The long-term survival study of unpaced patients found that the coexistence of these conditions lowered survival rates further beyond what heart block alone produced.¹ If you are dealing with heart block on top of other cardiovascular problems, the margin for error shrinks considerably.

Driving Restrictions and Everyday Limitations

Even setting aside the medical dangers, living with an unpaced arrhythmia imposes practical restrictions that affect daily life. Many countries restrict driving for patients at risk of cardiac syncope, on the reasonable grounds that losing consciousness behind the wheel can kill other people. The specific rules vary substantially from country to country, but the underlying principle is consistent: if you have a condition known to cause sudden loss of consciousness, you may be barred from driving until it is treated.¹¹

For some people, this alone is reason enough to proceed with pacemaker implantation. The ability to drive, work, and participate in normal activities can be severely curtailed by an untreated arrhythmia, even if the person has not yet fainted. Physicians are often legally obligated to inform patients of driving restrictions, and in some jurisdictions, to notify licensing authorities. Choosing not to get a pacemaker does not just affect your health. It can reshape your independence.

Access Barriers and Disparities

For some patients, the question is not whether they want a pacemaker but whether they can get one. Socioeconomic factors play a documented role in pacemaker outcomes. A nationwide analysis of pacemaker implantations found that low-income patients who did receive a pacemaker had roughly 39 percent higher odds of dying in the hospital compared to higher-income patients.¹² Research on newer leadless pacemakers has also found that African American race, prior heart attack, heart failure, kidney disease, and higher levels of social deprivation are all linked to worse outcomes at one year.¹³

These disparities suggest that the people most vulnerable to going without a pacemaker are often the same people who face the greatest barriers to receiving one. Delayed access, limited insurance coverage, lack of nearby facilities with electrophysiology services, and the sheer cost of the device and procedure all contribute. In lower-income countries, reuse of sterilized pacemakers has been explored as one strategy to address the gap, but the problem remains vast. The practical reality is that millions of people worldwide live with pacing-indicated conditions they will never have treated.

Choosing to Stop or Forgo Pacing at End of Life

There is one context in which not having a pacemaker, or turning one off, is a considered and medically supported decision. For patients with terminal illness, continued pacing can prolong the dying process in ways that conflict with their wishes. Pacemaker deactivation is legally and ethically recognized as a form of treatment withdrawal, no different in principle from discontinuing a ventilator or dialysis.

A documented case of palliative pacemaker deactivation described a pacing-dependent patient who made a capacitated decision to withdraw cardiac pacing. Comfort medications were administered, and the patient died peacefully 18 hours after the device was turned off.¹⁴ This scenario is fundamentally different from a younger or otherwise healthy person declining a recommended pacemaker. The goals of care are different, the prognosis is different, and the ethical framework shifts from preserving life to preserving comfort and autonomy. Palliative care teams are increasingly trained to guide these conversations, and advance directives can specify preferences about device management well before the end-of-life situation arises.