High-dose antibiotics are the cornerstone of treatment for<unk> . These antibiotics are administered by the intravenous (IV) route to maximize diffusion of antibiotic molecules into vegetation(s) from the blood filling the chambers of the heart. This is necessary because neither the heart valves nor the vegetations adhering to them are supplied by blood vessels. Antibiotics are typically continued for two to six weeks depending on the characteristics of the infection and the causative microorganisms. Antibiotic treatment lowers the risk of embolic complications in people with<unk> . In acute endocarditis, due to the fulminant inflammation, empirical antibiotic therapy is started immediately after the blood has been drawn for culture to clarify the bacterial organisms responsible for the infection. This usually includes vancomycin and ceftriaxone IV infusions until the infecting organism is identified and the susceptibility report with the minimum inhibitory concentration becomes available. Once this information is available, this allows the supervising healthcare professional to modify the antimicrobial therapy to target the specific infecting microorganism. The routine use of gentamicin to treat endocarditis has fallen out of favor due to the lack of evidence to support its use (except in infections caused by Enterococcus and nutritionally variant streptococci) and the high rate of complications. In cases of subacute endocarditis, where the person's hemodynamic status is usually stable, antibiotic treatment can be delayed until the causative microorganism can be identified. Viridans group streptococci and Streptococcus bovis are usually highly susceptible to penicillin and can be treated with penicillin or ceftriaxone. Relatively resistant strains of viridans group streptococci and Streptococcus bovis are treated with penicillin or ceftriaxone along with a shorter two-week course of an aminoglycoside during the initial phase of treatment. Highly penicillin-resistant strains of viridans group streptococci, nutritionally variant streptococci like Granulicatella sp., Gemella sp., Abiotrophia defectiva, and Enterococci are usually treated with a combination therapy consisting of penicillin and an aminoglycoside for the entire duration of 4–6 weeks. Some people may be treated with a relatively shorter course of treatment (two weeks) with benzyl penicillin IV if infection is caused by viridans group streptococci or Streptococcus bovis as long as the following conditions are met: * Endocarditis of a native valve, not of a prosthetic valve * A MIC ≤ 0.12 mg/l * A complication such as heart failure, arrhythmia, or pulmonary embolism occurs * No evidence of extracardiac complication like septic thromboembolism * No vegetations > 5 mm in diameter conduction defects * Rapid clinical response and clearance of bloodstream infection Additionally, oxacillin-susceptible Staphylococcus aureus native valve endocarditis of the right side can also be treated with a short 2-week course of a beta-lactam antibiotic such as nafcillin with or without aminoglycosides. Histopathology of a vegetation of bacterial endocarditis, taken from a valve repair, H&E stain. In a consistent clinical setting, neutrophils and fibrin is enough to diagnose a bacterial vegetation, even without visible bacterial colonies. The main indication for surgical treatment is regurgitation or stenosis. In active<unk> , the surgery should remove enough leaflet tissue to ensure eradication of the infectious process. Subsequent valve repair can be performed in limited disease. Replacement of the valve with a mechanical or bioprosthetic artificial heart valve is necessary in certain situations: * Patients with significant valve stenosis or regurgitation causing heart failure * Evidence of hemodynamic compromise in the form of elevated end-diastolic left ventricular or left atrial pressure or moderate to severe pulmonary hypertension * Presence of intracardiac complications like paravalvular abscess, conduction defects or destructive penetrating lesions * Recurrent septic emboli despite appropriate antibiotic treatment * Large vegetations (> 10 mm) * Persistently positive blood cultures despite appropriate antibiotic treatment * Prosthetic valve dehiscence * Relapsing infection in the presence of a prosthetic valve * Abscess formation * Early closure of mitral valve * Infection caused by fungi or resistant Gram-negative bacteria. The guidelines were recently updated by both the American College of Cardiology and the European Society of Cardiology. There was a recent meta-analysis published that showed surgical intervention at seven days or less is associated with lower mortality.
Infective endocarditis
Libman–Sacks endocarditis
Loeffler endocarditis
Nonbacterial thrombotic endocarditis
Subacute bacterial endocarditis
Tuberculous pericarditis
Nocardiosis
Ischemic cardiomyopathy