Case history
A 72-year-old Asian woman was admitted to our hospital with a three-week
history of intermittent fever and general fatigue. Her past medical
history was notable for moderate mitral valve regurgitation, which was
stable and being followed by a cardiovascular surgeon every year with no
medication for 10 years. She has undergone total hysterectomy for
uterine myoma at the age of 47 years. Three months before admission,
transthoracic echocardiography showed moderate mitral valve
regurgitation (Figure 1) and no vegetation on any valves. She had no
recent medical histories of diabetes mellitus, weight loss,
odontotherapy, and skin disease. Moreover, she had no family history of
cardiovascular disease, and she did not smoke and drink.
Physical examination showed body mass index of 19.3
kg/m2, body temperature of 38.4 ºC, regular heart rate
at 100 beats/ minute, blood pressure of 95/54 mmHg, respiratory rate of
12 breaths/ minute, and oxygen saturation of 98% on room air. She was
previously known to have a grade 2 or greater pansystolic murmur at the
apex, a Janeway lesion on the sole of the left foot, and no skin
lesions. The remainder of the examination, including the range of motion
of lumbars and neurologic examination, was unremarkable.
White blood cell count was 5,530/ µL, hemoglobin was 10.3 g/dL,
C-reactive protein (CRP) level was 1.43 mg/dL, and erythrocyte
sedimentation rate (ESR) was 78 mm/h. All four sets of blood cultures
revealed S. warneri . Transesophageal echocardiography showed a
5-mm motile vegetation on the anterior cusp of the mitral valve (Figures
2A and 2B) and mitral valve regurgitation. Contrast-enhanced thoracic
and abdominal computed tomography showed no abscess. Brain
diffusion-weighted magnetic resonance imagining (MRI) revealed a
high-signal area on the left cerebellum (Figure 3). Sagittal short-T1
inversion recovery MRI demonstrated the high-signal lesions on the disk
between the 9th and 10th thoracic vertebrae and vertebral bodies (Figure
4). These findings met the two major and three minor Duke criteria for a
definitive diagnosis of IE10.
She was treated with initially cefazoline at 2 g every 8 hours. Based on
the subsequent antimicrobial susceptibility test results, we changed the
antibiotics to intravenous penicillin G four million units every 4 hours
for 6 weeks, after the blood culture turned out negative on day 3. On
day 14, transesophageal echocardiography showed resolution of the
vegetation. She was discharged on day 45 and was continued on treatment
with oral amoxicillin 250 mg every 8 hours for 6 months, until the CRP
and ESR normalized11.