Echocardiography, especially transesophageal echocardiography (TEE) for patients with prosthetic valves, is important for both diagnosis and management decisions. A positive finding of vegetation constitutes a major criterion for diagnosis, second only to blood cultures. Echocardiography also provides important information’ about other valvular abnormalities, abscesses, leaflet perforation, pericarditis, and ventricular function; serial studies are important in medically unresponsive patients to change management or to consider surgery. Outcome is markedly affected by complications. Sensitivity for detecting vegetation is 50-70% by transthoracic echocardiography and 95% with TEE. A negative study has some negative prognostic indicators but does not exclude IE. Because of the numerous complications of PVE. patients with suspected IE should have TEE; the high mortality rate (up to 50% in late PVE and 40-80% in early PVE) is best countered with aggressive management.
Aortic valve endocarditis with a ring abscess on TEE.
What are the definite indications for surgery in IE?
• Acute valvular dysfunction (i.e., severe mitral regurgitation or aortic insufficiency)
• Myocardial invasion
• Antibiotic-resistant organism and persistent sepsis
• Continuing (intractable) congestive heart failure
• Nonfatal emboli
If a clinical diagnosis of IE of a native valve is certain, which empirical therapy should be used while blood cultures are being incubated, barring regional-specific modifications?
Vancomycin and gentamicin should be used in suspected drug users, as S. aureus is resistant to beta-lactam antibiotics. If the clinical picture is acute endocarditis with methicillin-susceptible staphylococci, nafcillin or oxacillin plus gentamicin may be used.
In 1990 the American Heart Association changed its Recommendations for Infectious Endocarditis Prevention to replace penicillin as the primary dental agent. With what drug was penicillin replaced? What other change was made?
Amoxicillin, 3.0 gm orally 1 hour before the procedure and 1.5 gm 6 hours after the initial dose, replaces penicillin as the standard antibiotic for routine dental procedures (for patients allergic to amoxicillin and penicillin, erythromycin or clindamycin should be used). Also of significance were the deletion of gastrointestinal endoscopy from the list of procedures for which protection is warranted, regardless of accompanying biopsy procedures, and provisions for routine use of oral regimens in high-risk patients (e.g., those with prosthetic valves) for dental, oral, or upper respiratory procedures.