2023 Volume 5 Issue 3 Pages 99-100
Isolated pulmonary valve endocarditis is a rare type of right-sided infective endocarditis (IE).1 Diagnosis of isolated pulmonary valve endocarditis is difficult using transthoracic and transesophageal echocardiography (TTE and TEE, respectively). Herein, we report a case of IE in the pulmonary valve that was detected by electrocardiography-gated cardiac computed tomography (CT).
A 58-year-old man with a history of atopic dermatitis presented with sepsis. Blood cultures indicated the presence of methicillin-sensitive Staphylococcus aureus (MSSA). Although IE could not be ruled out as the cause of the bacteremia, obvious vegetation was not detected by TTE, TEE, and contrast-enhanced CT (non-electrocardiography-gated) upon admission. Antibiotic treatment for MSSA was started and blood cultures were negative on Day 8. We subsequently performed TTE twice, which revealed no vegetation on the pulmonary valve. However, a repeated contrast-enhanced CT (non-electrocardiography-gated) on Day 33 for the purpose of finding the source of the bacteremia revealed a shadow defect near the pulmonary valve (Figure A). TTE (Figure B,B’) performed at that time also revealed a small verrucous finding on the right ventricular side of the pulmonary valve, although this finding was not clear on TEE. We performed electrocardiography-gated cardiac CT, which showed the verrucae on the pulmonary valve (Figure C,C’) with greater clarity. In addition, the 4-dimensional construction revealed a more defined structure of the pulmonary valve and showed a 3.0-mm×7.0-mm vegetation on the pulmonary valve (Figure D). Because there was no embolism and organ failure due to the vegetation, it was determined that there was no indication for emergency surgery. Therefore, antibiotics therapy was continued. After 6 weeks of antibiotic therapy, the patient was discharged with complete resolution of IE without any complications. To our knowledge, this is the first report showing that electrocardiography-gated cardiac CT may be useful in detecting relatively small pulmonary valve IE.
The vegetation (yellow arrows) on the pulmonary valve. (A) Contrast-enhanced computed tomography (CT; non-electrocardiography-gated) on Day 33 after admission. (B,B’) Transthoracic echocardiography in the diastolic phase. White arrows indicate the reverse jet. (C,C’) Electrocardiography-gated cardiac CT in the diastolic phase. (D,D’) 4-dimensional CT images in the systolic (D) and diastolic (D’) phases. Ao, aorta; LV, left ventricle; RA, right atrium; RV, right ventricle.
