A 68-year-old male presented with night sweats, fatigue, and shortness of breath for 5 weeks. His past medical history included uncorrected perimembranous ventricular septal de-fect (VSD) and previous infective endocarditis (IE) treated conservatively several years ago. Clinical examination revealed pansystolic murmur and Janeway lesions in bilateral heels. Blood inflammatory markers were high [C-reactive protein (CRP) = 72 mg/L, white blood cells = 12000/mm3]. Blood cultures were positive for Streptococcus sanguinis. Transthoracic echocardiography was suspicious of IE of the mitral valve. IE was confirmed by transoesophageal echocardiography. Vegetations were seen on the mitral (Fig. 1A, Supplementary movie 1), aortic (Fig. 1B, Supplementary movie 2), tricuspid (Fig. 1C, Supplementary movie 3, 4, and 5), and pulmonary (Fig. 1D, Supplementary movie 6 and 7) valves. There was also a large vegetation associated with the VSD (Fig. 1E, Supplementary movie 8, 9, 11, and 12), which seemed to protrude from it (Fig. 1F). The patient was treated with intravenous amoxicillin and gentamicin with clinical improvement and fall in CRP (8.5 mg/L) after 4 weeks of treatment. Mutual agreement between cardiologists and cardiac surgeons was to complete the antibiotic therapy for another 2 weeks and follow-up with serial echocardiograms.
IE affecting all valves is extremely rare, especially when the pulmonary valve is involved (only 1.5% to 2.0% of hospital admissions for IE).1) In this case, we thought that the pulmonary valve was actually affected because of the trajectory of the jet from the VSD (Fig. 1G, Supplementary movie 10) that abutted the valve.
Streptococcus sanguinis is a gram-positive coccus which belongs to the normal human mouth flora, particularly found in dental plaques.2) It is a known cause of subacute IE, especially in patients with congenital heart disease, after oral surgery.3) Notably, our patient mentioned frequent usage of dental floss.
References
1. Ramadan FB, Beanlands DS, Burwash IG. Isolated pulmonic valve endocarditis in healthy hearts: a case report and review of the literature. Can J Cardiol. 2000; 16:1282–1288.
2. Kolenbrander PE, Ganeshkumar N, Cassels FJ, Hughes CV. Coaggregation: specific adherence among human oral plaque bacteria. FASEB J. 1993; 7:406–413.
3. Turner LS, Kanamoto T, Unoki T, Munro CL, Wu H, Kitten T. Comprehensive evaluation of Streptococcus sanguinis cell wall-anchored proteins in early infective endocarditis. Infect Immun. 2009; 77:4966–4975.