Anatomically, infective endocarditis is characterized by a combination of vegetations and destructive lesions:

1. A vegetation presents as an oscillating mass attached to a valvular structure, with a motion independent of that of the valve, but may also present as non-oscillating mass with atypical location. Transthoracic echo has a sensitivity of 75% forthe diagnosis of vegetations, which may be increased to 85-90% by performing TOE. However, the sensitivity of TOE is reduced in prosthetic valves and in infective endocarditis affecting intracardiac devices such as pacemakers.
2. An abscess typically presents as a perivalvular zone of reduced echo density, without colour flow detected inside, and may be complicated by pseudoaneurysm and fistula (see page 13). The sensitivity of TOE for the diagnosis of abscess is 90% with high additional value when compared with transthoracic echo.
3. Other destructive lesions may include valve aneurysm, perforation, or prolapse, and chordal or less frequently papillary muscle rupture. The main consequences of these lesions are severe valve regurgitation and heart failure. TOE is of major value for their assessment.