1 INTRODUCTION
Infective endocarditis (IE) is an inflammatory disease caused by endocardial infection with pathogenic microorganisms that can affect the heart valve or atrioventricular wall endocardial surface, with vegetation formation (e.g., thrombus)1. IE is common in adults but not in children2, especially right-sided infective endocarditis (RSIE)3. We shared two cases to highlight the importance of diagnostic thinking in the ultrasound diagnosis of RSIE.
2 CASE 1
A 6-year-old child was admitted to our hospital with a fever and cough. The physical examination revealed a high body temperature, tachycardia, and a holosystolic murmur between the three and four intercostals on the left edge of the sternum. The laboratory tests of the peripheral blood showed that the WBC count was 21.8 x 109/L with 83% neutrophils, hemoglobin was 6.4 g/dL, and C-reactive protein was 10.1 g/dL. The chest x-ray showed focal pulmonary infiltrates, and multiple blood cultures (24 h apart) were negative. Meanwhile, the transthoracic echocardiography showed an overall enlarged heart and a subaortic ventricular septal defect (VSD) of 0.4 cm with a left-to-right shunt (Figure 1A). A 1.1 x 0.5 cm mass was attached to the anterior tricuspid valve, interrupted in continuity, and accompanied by severe tricuspid regurgitation (Figure 1B,C,D). Considering all her features, vegetations on the tricuspid valve were strongly suspected rather than thrombosis or rheumatic valvular heart disease.