**7. Surgery and the role of echocardiography**

Although patients may respond to prolonged antibiotic therapy alone, up to 50% will require surgical intervention [118]. Early surgery within the first week of antimicrobial therapy can improve survival in complicated left-sided IE; however, it may increase the risk of relapse and prosthetic valve dysfunction [119]. Echocardiography is fundamental in identifying important complications and prognostic markers that influence the timing of surgery.

Heart failure and embolism are the leading causes of mortality. Early surgery for left-sided IE is generally indicated in the following circumstances: (a) congestive cardiac failure, (b) periannular extension, for example, abscess and fistula, (c) large vegetations (>30 mm or possibly >15 mm) or recurrent emboli (>10 mm), (d) difficult to treat organisms such as *S. aureus,* multiresistant microbes, or fungi, (e) prosthetic valve endocarditis especially with Gram-negative, non-HACEK organisms, and (f) persistent sepsis or uncontrolled intracardiac infection including enlarging vegetations, despite appropriate antibiotics [17, 27].

Perioperative pre-pump 2D and 3D TEE provides the surgeon with a comprehensive real-time assessment of the extent of intracardiac pathology and cardiac hemodynamic status immediately prior to the procedure. A decision can be made on the feasibility of repair versus valve replacement and allows planning of the surgical strategy. The postpump TEE assesses cardiac function, hemodynamics, and the adequacy of surgical procedure. In addition, imaging can ensure the heart is appropriately 'de-aired' prior to removal of the cardiac vent. Intraoperative TEE for IE has been shown to positively impact on at least one of these factors in approximately one-third of operations [120].
