In a patient with aortic‑valve infective endocarditis and severe aortic regurgitation, what specific complications should be sought on transesophageal echocardiogram?

Specific Complications to Assess on TEE in Aortic Valve Infective Endocarditis with Severe Aortic Regurgitation

In a patient with aortic valve infective endocarditis and severe aortic regurgitation, TEE must specifically evaluate for perivalvular abscess, pseudoaneurysm, fistula formation, valve perforation, and prosthetic valve dehiscence—all of which are indications for urgent surgical intervention. 1

High-Priority Perivalvular Complications

Perivalvular Abscess

• Appears as thickened, non-homogeneous perivalvular tissue with echodense or echolucent characteristics 1
• TEE has superior sensitivity compared to TTE for detecting abscesses, particularly in the aortic and mitral valve regions 1, 2
• Critical caveat: Early abscesses may appear only as nonspecific perivalvular thickening and can be missed on initial TEE 1, 3
• The American Heart Association recommends repeat TEE in 3-5 days if clinical suspicion persists despite negative initial imaging 3
• Abscess formation is more common with aortic valve endocarditis (6%) compared to mitral valve (0%) 4
• Presence of abscess is an independent predictor of in-hospital mortality and 1-year mortality 1

Pseudoaneurysm

• Identified as a pulsatile perivalvular echo-free space with flow detected on color Doppler 1
• Develops over time from progressive tissue destruction, so negative early TEE does not exclude future development 1, 3
• CT may be superior to echocardiography in visualizing the full extent of pseudoaneurysms, particularly in prosthetic valves 1

Fistula Formation

• Abnormal communication between cardiac chambers or between the aorta and adjacent structures 1
• Like pseudoaneurysms, fistulae develop progressively and may not be evident on early imaging 1, 3
• TEE with color Doppler is essential for detecting abnormal flow patterns 1

Valve Perforation

• Appears as a defect in the valve leaflet, often with eccentric regurgitant jet 1
• 3D echocardiography is particularly useful for accurate description of perforation location and size 1
• Valve perforation is an independent predictor of 1-year mortality 1

Vegetation Characteristics Requiring Assessment

Size and Mobility

• Vegetations >10 mm are associated with significantly higher embolic risk 1, 5, 4
• Mobile vegetations carry increased embolic potential compared to fixed vegetations 5, 6
• The American Heart Association notes that vegetation size >10 mm is an independent risk factor for subsequent embolism by multivariate analysis 4

Location-Specific Risk

• Aortic valve vegetations appear on the ventricular surface of leaflets 7
• Anterior mitral valve involvement (when present as secondary "kissing lesion") carries higher embolic risk 1

Vegetation Evolution

• Increasing vegetation size during antibiotic therapy indicates treatment failure and increased embolic risk 1, 5
• Failure to decrease vegetation size predicts higher risk of embolic complications 1
• Most vegetations (83.8%) remain constant in size under therapy, which does not worsen prognosis 1

Valvular Dysfunction Assessment

Severity of Regurgitation

• Quantify the degree of aortic regurgitation using multiple parameters including vena contracta, regurgitant volume, and regurgitant fraction 1
• Severe prosthetic valve dysfunction is an indication for early surgery 1
• New or worsening valvular regurgitation during treatment suggests progressive valve destruction 1

Prosthetic Valve Dehiscence

• Identified as abnormal rocking motion of the prosthetic valve with paravalvular regurgitation 1
• TEE is significantly more accurate than TTE for prosthetic valve assessment 1
• Structural components of prosthetic valves create acoustic shadowing on TTE, making TEE essential 1

Secondary Cardiac Complications

Ventricular Function

• Left ventricular ejection fraction <40% is an independent predictor of in-hospital mortality 1
• Assess for regional wall motion abnormalities suggesting coronary embolization 1
• Right ventricular function assessment is critical, particularly if tricuspid valve involvement is suspected 1

Conduction Abnormalities

• New atrioventricular block suggests perivalvular extension into the conduction system 1, 8
• Complete heart block indicates extensive perivalvular disease requiring urgent surgical intervention 8
• The American Heart Association recommends TEE when new AV block develops, even if initial imaging was negative 1

Critical Timing Considerations

When to Repeat TEE

• Repeat TEE is mandatory with any change in clinical status: new murmur, persistent fever, heart failure, new conduction abnormalities, or embolic events 1
• The American Heart Association recommends repeat imaging 3-5 days after negative initial TEE if clinical suspicion remains high 3
• Serial imaging is justified in prosthetic valve endocarditis due to the dynamic nature of complications 1

Intraoperative TEE

• Intraoperative TEE is recommended for all patients undergoing valve surgery for endocarditis 1
• Provides assessment of interval changes since preoperative imaging and confirms adequacy of surgical repair 1
• Critical for detecting mechanical complications of surgery 1

Common Pitfalls to Avoid

• Do not rely on a single negative TEE to exclude endocarditis complications—sensitivity is approximately 90% for device-related infections and may miss early abscesses 1, 3
• Small vegetations (<5 mm) or those that have already embolized may not be visible on either TTE or TEE 1, 7
• Anterior prosthetic ring abscesses may be poorly visualized by TEE and require complementary imaging with CT 1
• Examine prosthetic aortic valves from multiple views: high esophageal views for the aortic aspect and deep transgastric views for ventricular aspects 1
• 3D echocardiography should be utilized for complex lesions to define size and dimensions accurately 1