Upon completion of the chapter, the reader will be able to:
Differentiate the causes and development of infective endocarditis (IE).
Identify the clinical presentation and laboratory evaluation for IE.
Assess diagnostic criteria used to evaluate a patient suspected of having IE.
Describe the most likely causative pathogens of IE, particularly in specific patient populations.
Develop appropriate pharmacologic treatment recommendations for patients with IE.
Define appropriate patient populations requiring prophylactic treatment, and differentiate appropriate drug regimens.
Devise a monitoring plan for patients with IE to determine treatment efficacy and discern any adverse effects.
Infective endocarditis (IE) is a serious infection affecting the lining and valves of the heart. Although this disease is mostly associated with infection of the heart valves, septal defects may become involved in some cases. Infections also occur in patients with prosthetic or mechanical devices or who are intravenous drug users (IVDUs). Bacteria are the primary cause of IE; however, fungi and atypical organisms may also be responsible pathogens.
Typically, IE is classified into two categories: acute or subacute. Differences between the two categories are based on the progression and severity of the disease. Acute disease is more aggressive, characterized by high fevers, leukocytosis, and systemic toxicity, with death occurring within a few days to weeks. This type of IE is often caused by more virulent organisms, particularly Staphylococcus aureus. Subacute disease is often caused by less virulent organisms, such as viridans group streptococci, producing a slower and more subtle presentation. It is characterized by nonspecific symptoms including fatigue, low-grade fever, and weight loss, with death occurring in several months.
Successful management of patients with IE is based on proper diagnosis, treatment with appropriate therapy, and monitoring for complications, adverse events, or development of resistance. The treatment and management of IE are best determined through identification of the causative organism. IE has varied clinical presentations; therefore, patients with this infection may be found in any medical subspecialty (ie, medicine, surgery, critical care, etc).
EPIDEMIOLOGY AND ETIOLOGY
Despite IE being a fairly uncommon infection, in the United States, there are about 10,000 to 15,000 new cases annually, accounting for an incidence of approximately three to seven cases per 100,000 persons-years.1,2 Although the exact number of cases is often difficult to determine, owing to the diagnostic criteria and reporting methods for this disease, its incidence remains similar overall but is increasing in older patients, those with prosthetic valves, and infections due to S. aureus. IE is now considered the fourth leading cause of serious infectious diseases syndromes following sepsis, pneumonia, and intraabdominal abscess.3 Although IE occurs at any age, more than 50% of cases occur in patients older than 50 years.1,2 IE in children continues to be uncommon and is mainly associated with underlying structural defects, surgical repair of ...