Echocardiography in Suspected Infective Endocarditis
Initial Imaging Approach
- The European Society of Cardiology recommends TTE as the first-line imaging modality in all patients with suspected IE, including those with Gram-negative bacteremia 1, 2, 3, 4.
- The presence of bacteremia with E. cloacae, combined with renal dysfunction and interstitial edema, raises significant concern for IE with potential complications including heart failure and embolic phenomena 3.
- The combination of bacteremia with renal dysfunction suggests possible systemic complications that could include IE with embolic phenomena to the kidneys 3.
When to Proceed to TEE
- TEE should be performed if the initial TTE is negative or non-diagnostic when clinical suspicion of IE remains high 1, 2, 3, 4, 5.
- Renal dysfunction in the setting of bacteremia may represent embolic phenomenon to the kidneys, which is a major criterion for IE and warrants aggressive imaging 3.
Clinical Decision Algorithm
- Order TTE immediately as first-line imaging, and ensure at least 2 sets of blood cultures have been obtained 1, 2, 3, 4.
- If TTE is positive for IE, proceed to TEE to evaluate for complications, and consult infectious disease, cardiology, and cardiac surgery 1, 2, 4, 6.
- If TTE is negative or non-diagnostic, proceed directly to TEE given high clinical suspicion 1, 2, 3, 4, 5.
Critical Pitfalls to Avoid
- Do not rely on TTE alone to exclude IE in bacteremic patients with systemic complications, as TTE has insufficient sensitivity 6.
- Do not delay TEE in patients with persistent fever, ongoing bacteremia, or signs of heart failure despite appropriate antibiotics 1, 2, 4, 5.
- Repeat echocardiography is indicated if new complications develop, such as new murmur, persistent fever, worsening heart failure, atrioventricular block, or embolic events 1, 2, 3, 4, 5.