Acute bacterial endocarditis
Patients at increased risk of this infection include intravenous drug users and patients with a predisposing heart condition including the presence of cardiac devices or prosthetic valves. Infection, including Candida infection, can occur after open heart surgery or valve replacement via catheter (TAVR).
Patients typically have fever. Cardiac murmur is usually present. On physical examination, there may be conjunctival hemorrhages, splinter hemorrhages, Janeway lesions, Osler nodes (tender, erythematous nodules that appear suddenly on the finger or toe pads), or Roth spots (pale lesions with surrounding hemorrhage seen in the fundi, with an ivory or white center surrounded by a red halo).
Imaging may reveal septic pulmonary infarcts, mycotic aneurysms, and stroke. Laboratory testing may reveal anemia, leukocytosis, elevated ESR, positive rheumatoid factor, hematuria, and red blood cell (RBC) casts in urine.
The diagnosis of endocarditis can be made by isolating the responsible organism in blood culture and by visualizing the valvular vegetation on echocardiography. Treatment is with prolonged antibiotics and sometimes with surgery to remove the source of infection. Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Streptococcus gallolyticus, and Streptococcus mitis/oralis have the highest prevalence of infective endocarditis in the setting of bloodstream infection.
Related topic: prosthetic valve endocarditis
I33.0 – Acute and subacute infective endocarditis
111286002 – Acute bacterial endocarditis
Differential Diagnosis & Pitfalls
- There are a variety of infections that can result in bacteremia without necessarily being associated with seeding of the heart valves. Cellulitis, septic joint, cholecystitis or cholangitis, and intraabdominal abscess are a few such infections.
- Cardiac devices such as pacemakers or left ventricular assist devices or other intravascular devices such as peripherally inserted central catheter (PICC) lines or ports can become infected and lead to prolonged bacteremia without the heart valves themselves necessarily being infected.
- Some conditions are associated with noninfectious valvular vegetations – systemic lupus erythematosus, Lambl's excrescences.
- Some conditions can be associated with skin findings that could appear similarly to those seen in endocarditis – cholesterol emboli, left ventricular thrombus with subsequent embolization, embolization of deep vein thrombosis in cases of right-to-left cardiac shunts, vasculitis.