Isolated right-sided valvular endocarditis in non-intravenous drug users

Characteristics of isolated right-sided endocarditis in patients without a pacemaker and who are not intravenous drug users (IVDU) are poorly understood. The aim of this study was to investigate the current frequency of this entity and describe its clinical, microbiological, echocardiographic and prognostic profile.

We have prospectively analyzed 17 consecutive cases of isolated right-sided endocarditis in non-IVDU who did not have a pacemaker, out of a total of 583 consecutive episodes of endocarditis (2.9%).

Mean age was 38+/-15 years; 11 of the 17 patients were men. Almost half of the patients had at least one predisposing disease. An intravascular catheter was the most frequent port of entry (35%). The most common signs and symptoms on admission were fever, dyspnea, septic pulmonary embolisms, pleural effusion and right-sided heart failure. The most frequent microorganism was Staphylococcus aureus (41%). In most cases (82%) the infection was located in the tricuspid valve. Recurrent pulmonary embolisms were the most frequent complication and the main cause for surgery, which was needed in 5 patients (29%). Two patients died during hospitalization (12%), both from septic shock. During follow-up one patient died of unknown causes 1 month after discharge, and other relapsed 3 months after discharge.

Isolated right-sided endocarditis should be included in the differential diagnosis of patients with febrile syndrome, respiratory symptoms and predisposing disease, even when they do not have a pacemaker and are not IVDU. The presence of intravascular catheters and Staphylococcus bacteriemia should heighten suspicion of endocarditis.