Cardiobacterium Workup

Updated: Jun 04, 2019
  • Author: Kerry O Cleveland, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Laboratory Studies

Older blood culture systems did not support the growth of HACEK bacteria aerobically or anaerobically; blood cultures needed to be held for up to 2-3 weeks with blind subcultures. Newer blood culture systems support the growth of HACEK bacteria within 5 days. Despite this, some experts continue to recommend holding blood cultures for an extended period (up to 1 mo) when a diagnosis of Cardiobacterium endocarditis is considered.

In one study, anemia was present in 18 of 23 (78%) patients with C hominis endocarditis

The erythrocyte sedimentation rate is usually elevated and may exceed 100 mm/h.

Urinalysis results may show evidence of glomerulonephritis, including hematuria and proteinuria.

Rheumatoid factor test results may be positive, and this finding is one of the minor criteria for endocarditis.


Imaging Studies

Transesophageal echocardiography (TEE) is considerably more sensitive than transthoracic echocardiography (TTE) in helping detect valvular vegetations. TTE is usually performed first; if findings are positive, TEE is probably unnecessary.

Positron emission tomography has been reported to be useful in the diagnosis of infective endocarditis, including cases due to Cardiobacterium infection. [12, 13]