Case Report
Written informed consent was obtained from the patient for the publication of this case report. At our medical center, institutional review board approval is not required for the publication of case reports.
An 18-year-old man presented to his local doctor with a 5-day fever and transient loss of consciousness. The loss of consciousness was not preceded by any signs, and no seizure activity was observed before or after the event. Thoracoabdominal computed tomography (CT) and head CT did not indicate any source of fever or cause of loss of consciousness; however, echocardiography showed a suspected verruca at the posterior mitral valve leaflet, prompting referral to our hospital with a diagnosis of infective endocarditis.
The patient had no history of cardiac disease, areas in the oral cavity requiring treatment, or history of drug use that may have contributed to the development of infective endocarditis. However, he had atopic dermatitis since childhood and had an exacerbation of facial erythema 4 months earlier, which subsequently improved 1 month prior.
Upon arrival at our hospital, he was alert but had a temperature of 38.7°C. No paralysis or other neurological abnormalities were noted. His skin condition was not poor and his abrasions were mild. Osler’s nodes were observed in both hands, and the right shoulder was tender, prompting suspicion of a septic shoulder.
The blood tests showed a white-blood cell count (WBC) of 14700 IU/dL, with neutrophilia but no leftward shift; C-reactive protein (CRP) level of 14.20 mg/dL; and procalcitonin level of 1.00 ng/mL. There was no anemia, and the liver and renal functions were normal. Blood culture showed methicillin-sensitive Staphylococcus aureus (MSSA). No other bacteria were detected. Echocardiography showed a verruca on the posterior mitral valve leaflet, which was mobile and about 10 mm in size (Fig. 1); mitral regurgitation was mild. Head magnetic resonance imaging (MRI) showed multiple acute cerebral infarctions in the left frontal deep white matter, bilateral occipital lobes, and corpus callosum ampulla (Fig. 2). Enhanced CT showed renal infarction and splenomegaly (Fig. 2). Spinal MRI showed no evidence of pyogenic spondylitis.
Antibiotic therapy was started and the patient was referred to our cardiovascular surgery department. Since systemic embolism was observed, we considered further embolism as highly likely and decided on urgent surgery.
MICS was performed through a small right thoracotomy. A verruca was found on the left atrial wall near the posterior mitral valve annulus. A small verruca was also seen on the anterior mitral valve leaflet (Fig. 3). Since there was no destruction of the mitral annulus and leaflet, verrucous excision was performed. Culture of the excised verruca also showed MSSA.
Postoperatively, vancomycin and ceftriaxone were continued for 2 weeks and 6 weeks, respectively. There were no neurological complications and his general condition improved. His right shoulder pain was relieved, allowing him to elevate his right shoulder. Postoperative head MRI showed no new cerebral infarcts and the abnormal signals disappeared. Further, there was no evidence of abscess formation or hemorrhage. Enhanced CT of the abdomen showed no significant evidence of renal infarction, and no exacerbation. There was no renal dysfunction. Echocardiography also showed no recurrence of verrucae.
The patient was discharged from the hospital after his fever abated. Blood tests showed a WBC count of 7800 IU/dL and a CRP level of 0.05 mg/dL. One year postoperatively, the patient had no recurrence of infection and no complications.