right - sided endocarditis occurs predominantly in intravenous drug users , patients with pacemakers or central venous lines and with congenital heart diseases . we describe a previously unreported condition of right - sided endocarditis in a patient with intravenous drug abuse attached to a muscular bundle of the right ventricular outflow tract . a 31-year - old woman with a history of intravenous drug abuse was admitted with acute lumbar pain and fever . c - reactive protein was 172 mg / l ( normal value < 5 ) and white blood cell count 18400/mm . chest radiography revealed a cavitating nodule of the right upper lobe consistent with a septic pulmonary embolism . transthoracic echocardiography ( tte ) found a pedunculated , highly mobile , mass in the right ventricular outflow tract ( figure 1 , video - see additional file 1 ) . it was not possible to describe precisely the attachment of this mass or its underlying cause . however , its floppy nature and echodensity was compatible with a vegetation . transesophageal echocardiography ( tee ) confirmed the absence of valvular involvement and congenital heart disease . this vegetation was at a distance from the pulmonary valve and appeared attached to the muscular bundle of the right ventricle ( figure 2 ) . long axis parasternal view showing vegetation ( arrow ) in the right ventricular outflow tract . transesophageal view ( 133 ) of two vegetations ( arrow ) attached to a muscular bundle . it has been estimated that up to 76 % of cases of endocarditis among intravenous drug abusers involve the right heart , compared with only 9 % in nonaddict patients . staphylococcus aureus causes 50 to 75 percent of cases of endocarditis associated with injection drug use . pulmonary valve endocarditis is mostly associated with tricuspid valve endocarditis and isolated pulmonary valve endocarditis is extremely rare . there have been isolated cases of infective endocarditis involving the interventricular septum or right ventricular free wall of individuals diagnosed with ventricular septal defect . a case report of an isolated right ventricular outflow tract vegetation without intravenous drug abuse was recently reported . at surgical examination , it was attached by a thin stalk to the right posterior ventricular wall . to our knowledge , there has been no previous report of vegetation attached to a muscular bundle of the right ventricular outflow tract . tee has been shown to be superior to tte in the detection of left - sided vegetations in endocarditis . in the study of san roman et al   using a monoplane probe , tee did not improve the diagnostic accuracy of tte in the detection of tricuspid vegetations in intravenous drug abusers . however tee is helpful in the substantial number of adults in whom tte imaging of the right heart , especially the pulmonary valve and right ventricular outflow tract , is poor due to technical limitations . in a study by herrera et al   comparing tee and tte for diagnosis of right - sided pathology , tee identified abnormalities in 37 of 56 cases ( 67 % ) confirmed by other methods in all cases , while tte correlated with tee findings in only 12 of 37 cases ( 32 % ) . tee is particularly useful in diagnosing pulmonary valve endocarditis because , in the adult , the pulmonary valve is the most difficult valve to visualize with tte . without histologic confirmation of the lesion we can not completely exclude other differential diagnoses such as thrombus , marantic endocarditis or more likely benign or malignant heart tumors . right - sided cardiac tumors are rare and most commonly found in the right atrium . myxomas , the most common type of primary cardiac tumors , are detected in the right ventricle in only 3 % of cases , with 10 % arising solely from the tricuspid valve , chordae or papillary muscle . papillary fibroelastomas are rare benign cardiac tumors typically attached to left - sided valves . however , among 93 patients of the largest reported series , four had right ventricular chamber localization and there were two pulmonary valve fibroelastomas . they are usually round , irregular in appearance , with well - demarcated borders and having a homogeneous texture . in conclusion , our case points to an unusual location of right - sided endocarditis in intravenous drug users . it confirms that tte remains an easy and highly sensitive first - line examination for the diagnosis of right - sided endocarditis . none declared . there are no financial or other relations that could lead to a conflict of interest . transthoracic echocardiography ( parasternal long - axis view ) demonstrating a pedunculated , highly mobile , mass in the right ventricular outflow tract . written consent was obtained from the patient 's relative for publication of the patient 's details .
backgroundright - sided endocarditis occurs predominantly in intravenous drug users , patients with pacemakers or central venous lines and with congenital heart diseases . 
 the vast majority of cases involve the tricuspid valve.case presentationa case of a 31-year - old woman with intravenous drug abuse who had a right - sided vegetation attached to the muscular bundle of the right ventricle is presented . 
 transthoracic echocardiography revealed a vegetation in the right ventricular outflow tract . 
 transesophageal echocardiography clearly showed that the 1.8 cm vegetation was not adherent to the pulmonary valve but attached to a muscular bundle.conclusionsour case points to an unusual location of right - sided endocarditis in intravenous drug users . 
 it confirms that tte remains an easy and highly sensitive first - line examination for the diagnosis of right - sided endocarditis .