Cardiac Device Infections
Abdel Kareem Abu Malouh
Jonathan P. Moorman
EPIDEMIOLOGY
The increased rate of cardiac device implantation in addition to an increased number of devices in older patients with more comorbid conditions has increased the rate of device infections.
Recent studies suggest an infection rate of 0.9 to 2.1 per 1,000 devices with higher rates for automated implantable cardioverter-defribillators (AICDs) than permanent pacemakers.
RISK FACTORS
|
PATHOGENESIS
Staphylococcal species cause the majority of infections.
Other causes include Corynebacterium species, Propionibacterium acnes, gram- negative bacilli, Candida species, and atypical mycobacteria.
Device contamination at the time of implantation appears to be the most common method of transmission.
Hematogenous seeding during episodes of bacteremia also occurs: more likely with Staphylococcus aureus and rarely with gram-negative bacilli.
Bacteria, particularly gram-positive cocci, adhere to hardware using biofilm production: difficult to sterilize.
Pocket infection may track along the intravascular leads to cause lead infection and endocarditis.
CLINICAL PRESENTATION
Local inflammatory changes at the generator site/pocket with or without cutaneous erosion of the generator or leads; abscess or sinus tract formation may occur.
Pain or discomfort at the generator site
Fever and other signs of systemic toxicity are often absent.
Patients may present with positive blood cultures with no local inflammatory changes at pocket site.
DIAGNOSIS
At least two sets of blood cultures should be obtained before the initiation of antimicrobial therapy in all patients with suspected cardiac device infection.
Positive blood cultures, particularly due to staphylococcal species, provide a strong clue to device infection (especially in the first 3 months following device implantation).
Transesophageal echocardiogram (TEE) is recommended in cases of bacteremia with underlying cardiac device and in cases of negative blood cultures with previous antibiotic use.
TEE is more sensitive than transthoracic echo for the diagnosis of associated endocarditis or lead vegetations.
Cultures of the generator pocket site may be useful in identifying the causative organism and guide future therapy.
Percutaneous aspiration of the device pocket should be avoided because of risk of introducing microorganisms into the pocket and causing device infection.Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
