Pacemaker infections
Pacemaker infections are medical conditions arising from the contamination of a pacemaker device, which is surgically implanted to manage abnormal heart rhythms. These infections are most frequently localized to the pocket where the pulse generator is placed and are typically caused by skin bacteria present during implantation. Certain individuals, particularly those with diabetes, underlying malignancies, or who have had frequent generator replacements, are at a higher risk for these infections. Symptoms can include fever and fatigue, and in some cases, signs may not appear until years after the pacemaker is implanted. Diagnosing a pacemaker infection involves blood cultures and echocardiograms to identify infection-related abnormalities. Treatment generally requires antimicrobial therapy along with the removal of the pacemaker hardware for effective resolution. Preventative measures include ensuring implantation by experienced surgical teams and the potential use of prophylactic antibiotics, which can lower the infection risk. Understanding these aspects can help patients and caregivers recognize, prevent, and address pacemaker infections effectively.
Pacemaker infections
- ANATOMY OR SYSTEM AFFECTED: Abdomen, cardiovascular system, chest, heart
Definition
Pacemaker infections are illnesses caused by contamination of the pacemaker, a small device consisting of a pulse generator and wire leads that is surgically implanted in the chest or abdomen to help control abnormal heart rhythms. Pacemaker infections most commonly occur in the pocket in which the part of the pacemaker called the generator is placed. Most infections are thought to occur through contamination of the pacemaker device by standard skin bacteria (such as staphylococci and corynebacteria) present at the time of implantation.
Pacemaker infections are more common in people who have diabetes mellitus, who use steroids, who have an underlying malignancy, who have an overlying skin disorder, who have a heart hematoma, who have emergency pacemaker placement, and who have had frequent generator replacements. There is also evidence that implantation of the device by an inexperienced surgical team increases infection risk.
Causes
Pacemakers, used to treat abnormal heart rhythms, are common devices in the United States. The device consists of a small pulse generator connected to the right chambers of the heart by two pacing leads. To keep the heart rate in a regular rhythm, the pulse generator’s computer chip creates an electrical impulse to stimulate the heart muscle to contract (squeeze) at a particular time and in a pattern. Pacemakers are implanted in the chests or abdomens in persons with too slow heart rates or with blocks in the natural electrical conduction system of their hearts.
Pacemaker infections most commonly occur in the area, or pocket, in which the pacemaker’s generator is placed. Most infections are thought to occur from contamination of the pacemaker device by standard skin bacteria that are present at the time of implantation. Even though the bacteria are present at the time of the pacemaker surgery, symptoms of the infection may not appear immediately. In some persons, symptoms of pacemaker infection may occur more than two years after surgery. Infection of the pacemaker’s leads and electrodes occurs less frequently than infections of the generator, although an infection in the generator pocket can spread up the leads to the heart and electrode tips.
Risk Factors
The risk factors for pacemaker infection are related to the person’s health, the conditions of the device implant, and the skill of the surgical team implanting the device. An increased risk of pacemaker infection exists in persons with diabetes mellitus, in persons with an underlying malignancy, in persons who use steroids, and in persons with an overlying skin disorder (particularly disorders such as pustules). Research also has determined that persons who had urgent placement of their original pacemaker, who have had frequent replacement of the pacemaker generator, who have hematoma formation, and whose surgical implantation was performed by an inexperienced team are also at increased risk for pacemaker infection.
Symptoms
The main symptoms of a pacemaker infection are a fever and fatigue. Other symptoms include an infection of the heart’s inner layer (endocarditis), a new or changing heart murmur, and abnormal growths on the tricuspid valves, pacemaker electrodes, or endocardium of the right ventricle or atrium. The infection may also cause blockage of the main artery of the lung by a clot called a pulmonary embolus.
Screening and Diagnosis
Diagnosis of a pacemaker infection should be considered in persons with pacemakers and unexplained fever and fatigue. The infection can be confirmed through blood cultures that identify specific infection-causing bacteria or pathogens and through an echocardiogram that demonstrates abnormal growths (vegetations) on a pacemaker lead or electrode. Cultures of the blood, the pacemaker pocket, and any wound site should also be used to help confirm a pacemaker infection. Definitive diagnosis of a pacemaker infection can be made upon finding a bacterium or other microorganism infecting the pacemaker pocket or blood.
Treatment and Therapy
The conservative treatment of a pacemaker infection of the generator or electrode, or both, is a combination therapy using antimicrobial agents tailored to the identified infectious agent and the removal of the pacemaker hardware. A relapse of the infection is usually associated with the failure to remove all hardware.
Prevention and Outcomes
The prevention of pacemaker infection is not guaranteed by the use of particular procedures or devices; however, the risk for infection can be decreased. Given identified risk factors, infection risk can be reduced by implantation of the pacemaker by an experienced surgical team using sterile procedures in a scheduled, not urgent, setting. Evidence exists that administering antibiotics, such as levofloxacin, before the procedure decreases the risk for infections. The risk of pacemaker infection can also be decreased through the implantation of drug-eluting devices, or stents, at the time the pacemaker is implanted. Drug-eluting devices emit antimicrobial medications directly at any potential infection site.
Bibliography
Chua, J. D., et al. “Diagnosis and Management of Infections Involving Implantable Electrophysiological Cardiac Devices.” Annals of Internal Medicine 133 (2000): 604.
De Oliveira, J. C., et al. “Efficacy of Antibiotic Prophylaxis Before the Implantation of Pacemakers and Cardioverter-Defibrillators.” Circulation: Arrhythmia and Electrophysiology 2, no. 1 (February, 2009): 29-34.
Eggimann, P., and F. Waldvogel. “Pacemaker and Defibrillator Infections.” In Infections Associated with Indwelling Medical Devices, edited by F. Waldvogel, and A. L. Bisno. Washington, D.C.: ASM Press, 2000.
Klug, D., et al. “Risk Factors Related to Infections of Implanted Pacemakers and Cardioverter-Defibrillators.” Circulation 116 (2007): 1349.
Lipsky, Martin S., Marla Mendelson, and StephenHavas. American Medical Association Guide to Preventing and Treating Heart Disease. Hoboken, N.J.: John, 2008.
Murphy, Joseph G., and Margaret A. Lloyd, eds. Mayo Clinic Cardiology: Concise Textbook. 3d ed. Rochester, Minn.: Mayo Clinic Scientific Press, 2007.
"Pacemaker." Mayo Clinic, 8 July 2023, www.mayoclinic.org/tests-procedures/pacemaker/about/pac-20384689. Accessed 4 Feb. 2025.