Infective Endocarditis

Abstract

Infective endocarditis (IE) is a relatively uncommon but potentially life-threatening infection of the cardiac endothelium. Most cases of infective endocarditis in children occur in those with congenital heart disease or who have had prior cardiac surgery. Most cases in adults occur on non-native valves and abnormal native valves, but infective endocarditis can involve normal heart valves and can occur in children and adults without identifiable risk factors. Gram-positive organisms, namely, Staphylococcus aureus and viridans group streptococci, are the most common causes of IE. HACEK organisms, enterococcus, pneumococcus, and, rarely, coagulase-negative staphylococci and non-HACEK gram-negative pathogens are also reported. Culture-negative endocarditis caused by atypical pathogens is also reported in children and adults. Signs and symptoms associated with infective endocarditis are often non-specific which can lead to a delay in diagnosis. Fever and cardiac murmurs are common features of infective endocarditis. Subacute presentations of illness are common in patients with infective endocarditis, but an acute presentation with rapid progression of sepsis-like illness can occur, especially with S. aureus. Diagnosis of infective endocarditis is based on clinical features, microbiological evidence, and echocardiographic findings. There is a role for molecular diagnostic studies in culture-negative cases. Urgent evaluation and management of hemodynamic status is critical in patients with infective endocarditis. Empirical antimicrobial therapy for infective endocarditis is based on the patient’s age, risk factors, comorbidities, and local antimicrobial susceptibility patterns. Recommendations from the American Heart Association can be used to guide treatment decisions for infective endocarditis, and specialist consultation should be considered. Prolonged antimicrobial therapy is recommended for infective endocarditis. Surgical intervention is necessary for some patients with infective endocarditis. Prevention of infective endocarditis by utilizing antibiotics prior to dental and certain other surgical procedures is only indicated for those with unrepaired cyanotic congenital heart disease or surgically repaired congenital heart disease with residual shunt or device, in those with a prosthetic heart valve, in cardiac transplant recipients and valvulopathy, and in those who have been previously diagnosed and treated for endocarditis.