Isolated tricuspid valve endocarditis in nonaddicted patients: a diagnostic challenge.

Isolated native nonrheumatic tricuspid valve endocarditis rarely is described in the absence of intravenous drug use, intracardiac catheters, or cardiac anomalies. We diagnosed tricuspid valve endocarditis in two elderly nonaddicted patients with recurrent pulmonary infiltrates, anemia, and microscopic hematuria that occurred during several months and was caused by Gemella morbillorum and Candida glabrata, respectively. We have reviewed 27 other cases of nonaddicted patients with tricuspid valve endocarditis from the literature and discussed etiology, clinical characteristics, and outcome. Mean age was 53.5 years (range, 22 to 74 years old), and 72% had underlying medical conditions. Staphylococcus oureus, Streptococcus bovis, and candida species were the causative organisms in 70% of the cases. Average duration of infection before diagnosis was 9.3 months. We conclude that isolated tricuspid valve endocarditis in nonaddicted patients occurs mainly in the middle-aged and older persons, mimicking chronic illness and community-acquired pneumonia. In the absence of a history of intravenous drug use, diagnostic delays are common. We suggest that right-sided endocarditis must be considered in any patient with the "Tricuspid Syndrome," consisting of recurrent pulmonary events, anemia, and microscopic hematuria. Careful evaluation of prior medical records and clinical course can be very helpful. Echocardiography and serial blood cultures provide the key to diagnosis.