Infective endocarditis continues to be an underdiagnosed and undertreated disease, in spite of a mortality which exceeds that of acute myocardial infarction. In the diagnosis of this disease, echocardiography—including transoesophageal echocardiography—has been a major breakthrough. While the traditional hallmarks of endocarditis were fever together with a new or changed heart murmur, cutaneous signs, and embolic events, echocardiography has enabled the direct visualisation of endocarditic lesions. Indeed, the widely acknowledged Duke criteria for endocarditis1 list echocardiographic signs as a major diagnostic criterion, which together with positive blood cultures allows the definite diagnosis of endocarditis (table 1). Recent work indicates that echocardiography should have an even more prominent place, because patients nowadays are very frequently pretreated with antibiotics before any blood cultures are drawn, leading to a high incidence of culture negative endocarditis.2

Transthoracic echocardiography detects vegetations with approximately 70% sensitivity.3 ,4 The use of transoesophageal echocardiography increases sensitivity and specificity to about 90%,4-7 mainly by detecting small vegetations that escape the transthoracic diagnosis. The diagnostic advantage of transoesophageal echocardiography is even more pronounced in abscesses and prosthetic valves, where transthoracic echocardiography may miss half or more of the lesions.8 ,9 At the same time, extension of the disease to other valves or to surrounding tissue, valvar defects, chordal rupture, fistulas, and other complications can be diagnosed, the severity of valvar regurgitation and hence hemodynamic stability can be assessed, and size and mobility of vegetations provide a rough estimate of the likelihood of embolism.5 ,10 ,11 Management decisions, especially the decision to proceed to early surgery, are facilitated by findings such as large vegetations, severe valvar regurgitation, abscess formation, prosthetic valve dehiscence, etc. Conversely, a negative transoesophageal echocardiogram has a negative predictive power of over 90%.12 …