[The usefulness of echocardiography in the diagnosis of prosthetic valve endocarditis: a comparison between the transthoracic and transesophageal approaches].

Transesophageal echocardiography is a new semi-invasive procedure whose practical application has yet to be precisely defined. The diagnosis of prosthetic valve endocarditis is particularly difficult with the transthoracic approach, either by thoracic conformation of patients who underwent cardiac surgery, or ultrasound attenuation caused by the prosthetic material. Transesophageal echocardiography is useful to overcome such limits with a new acoustic window, due to the proximity of the esophagus and the heart. During 15 months 18 patients with suspected prosthetic valve endocarditis were studied using both procedures. In patients with mitral prosthetic valves, transesophageal echocardiography provided information unobtainable by using the transthoracic procedure, while in patients with aortic prosthetic valves it only showed additional information in 1 case of abscess of the posterior valve ring. In conclusion, transesophageal echocardiography is useful to diagnose all patients with suspected prosthetic mitral valve endocarditis and might be performed in patients with aortic valve prostheses if the quality of the transthoracic procedure is poor.