Heart block: the wiring fault behind the dizzy spells, and the pacemaker that fixes it for good
Last updated September 3, 2026.
Heart block is a fault in the heart's electrical wiring: the signal from the top chambers is delayed or fails to reach the main pumping chambers, and the heartbeat slows, sometimes dangerously. It comes in degrees: first-degree is a delay, usually harmless and found by accident; second-degree drops some beats; and third-degree, complete heart block, disconnects the floors entirely, with a slow escape rhythm that causes dizzy spells, blackouts, breathlessness, and profound fatigue. The causes are mostly age-related scarring of the wiring, heart attacks, heart surgery, some medicines, and occasionally infection or inflammation; sometimes no cause is found. Diagnosis is by ECG, sometimes with a wearable monitor to catch the intermittent forms. The treatment for significant block is a pacemaker: a small device under the collarbone skin, with leads into the heart, placed in a procedure of about an hour under local anesthetic, and it fixes the problem at its root. Life with a pacemaker is ordinary for almost everyone: checks once or twice a year, mostly remotely now, a few sensible precautions, and the dizzy spells and blackouts gone. First-degree block usually needs no treatment at all, just awareness, and medicine-caused slowing often resolves by adjusting the drug.
What does it look like?
The significant degrees announce: dizzy spells and blackouts, sudden and without warning; breathlessness and fatigue out of proportion; a pulse that is slow, sometimes into the thirties or forties; and sometimes chest pain or confusion in older people. The milder degrees are silent, found on an ECG done for another reason. The blackout without warning, especially in someone older, is the presentation that earns the urgent ECG.
Why does it happen?
The wiring scars: age-related fibrosis is the commonest cause by far, then heart attacks, heart surgery or procedures, and medicines that slow the signal, beta blockers and some calcium-channel and rhythm drugs among them. Rarer causes include infections like Lyme disease, inflammatory conditions, and congenital forms. It is not caused by lifestyle choices or stress, and the scarred wiring does not heal; the pacemaker exists precisely because the fix is electrical, not medicinal.
How is it treated?
- A pacemaker is the fix for significant block, and it is a small procedure. About an hour under local anesthetic with sedation, a small cut below the collarbone, leads threaded down a vein into the heart, and most people go home the same or the next day.
- The milder degrees are watched, not treated. First-degree block and some second-degree patterns need no device, just periodic ECGs and a low threshold for reporting new dizziness.
- Medicine-caused slowing is fixed by adjusting the medicine. When a drug is doing the slowing, the prescription changes, and the wiring often recovers without any device.
- Life with a pacemaker is ordinary. Device checks once or twice a year, often from home by remote monitoring; ordinary exercise and travel; a few precautions around strong magnets and some medical procedures; and the symptoms that brought you there, gone.
When is it the emergency?
A blackout, especially without warning, is a same-day emergency assessment, and blackouts with injury, chest pain, or breathlessness are a 911 call. A resting pulse persistently under 40 with dizziness deserves same-day review. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Do I really have no choice about the pacemaker?
Complete heart block with blackouts is the clearest pacemaker indication in cardiology, so the honest answer is that the choice is real but lopsided. The wiring between your heart's floors has failed, the slow escape rhythm is what the blackouts are, no medicine repairs the wiring, and the blackouts owe no one a warning: the next one is as likely on stairs or a road as on a sofa. So the alternative is not no pacemaker and no change; it is no pacemaker and the falls. What you do choose is the timing and the team, and the speed being offered is the system protecting you, not rushing you. The men who hesitate a month usually say the same thing afterward: they wish they had the month back.
What is the procedure actually like?
Smaller than its reputation, and worth having in detail. About an hour, under local anesthetic with sedation, so you are drowsy but not under a general anesthetic. A small cut below the collarbone, the leads threaded down a vein into the heart under X-ray guidance, the device pocket made under the skin, and most people go home the same or the next day. The first weeks ask for one real adaptation: not raising that arm above the shoulder while the leads settle. The bruising looks dramatic and fades. The surprise most people report is how little it hurt, and how quickly the day felt ordinary again.
What changes in daily life with a pacemaker?
Less than you fear, and mostly at the margins. Exercise, walking, swimming, golf, travel, and sex all continue; airport scanners are fine with a device card shown, and MRI scans are possible with most modern devices under protocol. The lasting precautions are few: strong magnetic fields and arc welding deserve distance, some medical procedures need the team told first, and contact sports get an individual conversation. The device checks happen once or twice a year, increasingly from your own home by remote monitoring, and the battery lasts years, with replacement a smaller procedure than the first. The change you will actually notice is the one you want: the energy you forgot was normal, back.
Could they not just give me tablets instead?
No, and the reason is mechanical rather than a prescribing habit. Heart block at your degree is a wiring fault: the signal is not getting through, and there is no tablet that repairs scarred electrical insulation. The medicines that speed the heart exist only as a bridge in emergencies, and the drugs that sometimes cause a slow pulse are a different story entirely, those are adjusted and the wiring recovers, but that is not your story: yours is complete block with blackouts. When the fix for a problem is electrical, the honest treatment is electrical, and the pacemaker is the fix rather than the fallback.
Will I feel it, or set things off, or have to explain it forever?
You stop feeling it within weeks, literally and otherwise. The bump under the collarbone is noticeable at first and then just part of your outline; the device is silent; and it does not set off shop alarms in any way that matters, with a device card settling airport security in seconds. You tell doctors and dentists it is there because some of their equipment interacts, and that becomes a five-second sentence. The fear of explaining yourself forever is the newness talking: a pacemaker is one of the commonest devices in medicine, the people around you already include several, and within a year it is the least interesting thing about your health.
What happens if it stops working, or the battery dies?
The device is monitored, so surprises are designed out: the checks, mostly remote from your home, report the battery and the leads continuously, and a battery approaching its end is known months ahead, with the replacement, a smaller procedure than the first, scheduled at leisure rather than in a rush. The leads and device are engineered for years, the failure rate is low, and the monitoring is precisely why a failure is a scheduled event rather than an emergency. The thing the pacemaker asks of you is the one thing worth giving: keep the check appointments, and let the remote box sit plugged in. Everything else, it handles.