What a device infection is
A pacemaker, defibrillator (ICD), or CRT device has two parts: the generator — the metal “battery” that sits in a pocket just under the skin below the collarbone — and the leads, the insulated wires that run through a vein into the heart. An infection can settle on either part.
The reason these infections are taken so seriously comes down to one fact: bacteria can coat implanted hardware in a protective film (a biofilm) that antibiotics cannot reliably penetrate. Once that happens, the body and the antibiotics cannot sterilize the metal and plastic. The infection will keep coming back until the hardware is gone. That is why the standard of care for a truly infected system is to remove all of it — generator and every lead — not just treat with antibiotics.
Two patterns
Pocket infection stays mostly local, around the generator:
- Redness, swelling, warmth, and tenderness over the device
- Fluid or pus draining from the incision or the pocket
- The skin over the device thinning, or the edge of the device or a wire starting to push through the skin (called erosion or threatened erosion)
Lead and bloodstream infection is deeper and more serious. Bacteria living on the leads seed the bloodstream and can attach to the leads or a heart valve — a form of endocarditis. This tends to look like a general, systemic illness:
- Fevers, chills, and night sweats
- Fatigue and feeling unwell
- Sometimes no local signs at the pocket at all
A pocket infection that is not dealt with can travel inward to become a lead infection, which is one of the reasons we want to hear about local signs early.
Warning signs — when to call us
Please contact us promptly — do not wait for a routine appointment — if you notice any of the following, whether your device was implanted last month or ten years ago:
- Redness, swelling, warmth, or increasing tenderness over the device pocket
- Any fluid, pus, or bleeding draining from the site
- The device or a wire becoming visible, or the skin over it thinning or breaking down — call before it opens through the skin, when it is far easier to manage
- Fever, chills, or night sweats without an obvious cause
- Feeling generally unwell, run down, or feverish in the weeks to months after an implant or battery (generator) change
Catching a device infection early — especially a threatened erosion before the skin breaks — genuinely changes how involved the treatment has to be.
How we diagnose it
- Examination of the pocket and incision.
- Blood cultures to identify whether bacteria are in the bloodstream and exactly which antibiotics will work.
- Echocardiogram, usually a transesophageal echo (TEE), to look for vegetations — clumps of infection — on the leads or heart valves.
- Nuclear imaging (PET or tagged white-cell scans) in selected cases where the picture is unclear.
How we treat it
- Complete removal of the system. Every part — generator and all leads — is taken out, because leaving infected hardware behind allows the infection to persist. Removing leads that have been in place for years is a specialized procedure; see our page on lead extraction.
- IV antibiotics, with the length of the course depending on whether the infection was limited to the pocket or had reached the bloodstream and valves.
- Reimplantation later. If you still need a device, a new one is implanted once the infection is cleared — usually on the opposite side, and often as a separate, staged procedure rather than the same day.
Lowering the risk
Most implants never become infected, and several steps keep the risk low:
- Antibiotics given just before the implant, and strict sterile technique during the procedure.
- An antibacterial envelope placed around the generator in patients at higher risk (for example, certain repeat procedures).
- Good wound care afterward — keeping the site clean and dry, and not picking at or manipulating the incision or the device.
- Controlling diabetes and other conditions that raise infection risk.
When to check in with us
When in doubt about the device site, call — we would much rather see a pocket that turns out to be fine than miss an infection taking hold. If you develop unexplained fevers or feel unwell and you have an implanted device, make sure every doctor who sees you knows about the device, because it changes how your illness should be worked up.