The Onset of fever in a CIED recipient needs to be carefully investigated, as in all recipients of implantable devices such as prosthetic heart valves, vascular conduits, orthopaedic prostheses.

When fever is the marker of a well-defined organ disease, it will be treated accordingly.
On the contrary, when no definite sign or symptom of organ involvement is detected, care shall be exercised in the diagnostic work up. Especially when fever appears weeks or months after an infective or inflammatory disease, soft tissue injuries, surgery or invasive diagnostic/interventional procedures, a suspicion of bacteraemia/lead endocarditis should be raised.

A pattern of recurrent fever over many days (more than a week), though intermittent, should prompt medical attention and blood testing to investigate the possibility of bacteraemia (CRP, WBC count, hemoculture). A correct diagnosis is pivotal for effective treatment: this is the reason why empirical antibiotic treatment is strongly discouraged. Indeed, it may cause a delayed diagnosis, or also make impossible a causative diagnosis. The first-line approach by the general practitioner is to run blood testing and echocardiography, but in many cases a team of medical professionals is involved in the work up and treatment of a suspected infection of an implanted device.

While a definite diagnosis is being pursued, fever should be treated when exceeding 38°C, as it may trigger Arrhythmias, especially in subjects with ion channels disease ( Brugada-like, for instance). Paracetamol (500 to 1000 mg) and aspirin (500 to 100O mg) are the first-choice drugs. Paracetamol should be avoided in the event of recent alcohol intake or of liver impairment. Aspirin has to be used with caution in patients on oral anticoagulants, or with a history of bleeding. Sponge baths may also provide a small and short-lived but quick effect on body temperature.

Of paramount importance is the search of an entry site for pathogens, to treat any potential source of recurrent bacteraemia and relapsing infections.