IMPLICATION OF NEGATIVE RESULTS ON A MONOPLANE TRANSESOPHAGEAL ECHOCARDIOGRAPHIC STUDY IN PATIENTS WITH SUSPECTED INFECTIVE ENDOCARDITIS

Objectives. This study was conducted to determine the implications of negative findings on a transesophageal echocardiographic study in which neither a vegetation nor an abscess is identified in patients with clinically suspected infective endocarditis. Background. Echocardiography is the procedure of choice for evaluating suspected infective endocarditis in patients. Transesophageal echocardiography has been shown to be superior to transthoracic imaging. Although the importance of positive results or a diagnostic study is known, the significance of negative findings on a transesophageal study is not clear. Methods. All transesophageal echocardiographic studies performed over a 2-year period for suspected infective endocarditis were reviewed and the clinical course of patients with an initially negative study result was assessed to determine their final diagnosis. Results. Of the 105 patients identified, 65 had a negative transesophageal study result. In the majority of this group (56 of 65), an alternate diagnosis was made or there was no infective endocarditis on follow-up examination, or both. Of the remaining nine patients, four were treated for endocarditis without a definite diagnosis and five had infective endocarditis proved by either repeat transesophageal study (n = 3), pathologic findings (n = 1) or a diagnostic clinical course (n = 1). Gram-positive bacteremia and the presence of a prosthetic valve in the aortic position tended to be more common in the latter group. Conclusions. A negative transesophageal study result reduces the likelihood that endocarditis is present. Repeat examination, however, should be considered in high risk patients, such as those with prosthetic valves or unexplained bacteremia, to avoid a missed diagnosis.