Endocarditis : Diagnosis, Pathophysiology And Treatment
- Most patients with IE have risk factors, such as preexisting cardiac valve abnormalities.
- Most types of structural heart disease resulting in turbulence of blood flow will increase the risk for IE. Some of the most important include the following:
- Presence of a prosthetic valve (400-fold increased risk)
- Previous endocarditis (400-fold increased risk)
- Complex cyanotic congenital heart disease (e.g., single ventricle states)
- Surgically constructed systemic pulmonary shunts or conduits
- Acquired valvular dysfunction (e.g., rheumatic heart disease)
- Hypertrophic cardiomyopathy
- Mitral valve prolapse with regurgitation
- Intravenous drug abuse
- Three groups of organisms cause most cases of IE: streptococci (55% to 62%), staphylococci (25% to 35%), and enterococci (5% to 18%)
- Important clinical signs, especially prevalent in subacute illness, may include the following peripheral manifestations (â€œstigmataâ€) of endocarditis:
- Janeway lesions
- Splinter hemorrhages
- Clubbing of the fingers
- Roth spots
- Without appropriate antimicrobial therapy and surgery IE is usually fatal. With proper management, recovery can be expected in most patients.
Congestive heart failure
Endocarditis caused by resistant organisms such as fungi and gram-negative bacteria
Left-sided endocarditis caused by Staphylococcus aureus
Prosthetic valve endocarditis
- The most important approach to treatment of IE includes isolation of the infecting pathogen and determination of antimicrobial susceptibilities, followed by high-dose, bactericidal antibiotics for an extended period.
- For most patients 4 to 6 weeks of therapy are required.
- Specific recommendations for treating IE caused by the most common organisms are discussed in this chapter.
- Î²-Lactam antimicrobials, such as penicillin G, nafcillin, and ampicillin, remain the drugs of choice for streptococcal, staphylococcal, and enterococcal endocarditis, respectively.
- For some pathogens, such as enterococci, the use of synergistic antimicrobial combinations (including an aminoglycoside) is essential to obtain a bactericidal effect.
- Surgery is an important adjunct to management of endocarditis in certain patients. In most cases, valvectomy and valve replacement are performed to remove infected tissues and restore hemodynamic function. The most important indications for surgical intervention in the past have been heart failure in left-sided IE and persistent infections in right-sided IE.