Natural history of tricuspid valve endocarditis: a two dimensional echocardiographic study.

Sixteen patients with tricuspid valve endocarditis were studied to define (1) what clinical or echocardiographic subsets are at risk for complications or need for tricuspid valve surgery, and (2) the long-term two dimensional echocardiographic course of tricuspid vegetations. There were 18 episodes of tricuspid endocarditis in the 16 patients; 12 patients had a history of intravenous drug abuse. Staphylococcus aureus was the most common infecting organism (11 patients). Persistent infection, cardiomegaly or radiography and right-sided heart failure were present in all patients undergoing tricuspid valve surgery and in none of the medically treated patients. Echocardiographic studies demonstrated tricuspid vegetations in 10 patients by M mode and in all 16 by two dimensional technique. Vegetation size, right ventricular enlargement and abnormal septal motion were not of prognostic significance. Two dimensional echocardiographic measurements of vegetation size correlated with surgical pathologic measurements in the four patients who underwent surgery. Serial two dimensional echocardiographic studies were available in eight patients a mean of 10.6 (range 2 to 19.5) months after the initial study: Vegetations had decreased in size or disappeared in seven patients and were essentially unchanged in one patient. It is concluded that (1) two dimensional echocardiography increases the detection of tricuspid valve vegetations and accurately estimates their size; (2) persistent infection, cardiomegaly and right-sided heart failure identify a subgroup of patients with tricuspid endocarditis who may have increased risk; (3) no M mode or two dimensional echocardiographic feature is a predictor of outcome; and (4) tricuspid valve vegetations tend to resolve with time.