Infective endocarditis (IE) is an infection of the endocardial surface of the heart that
affects the cardiac valves. It is treated with penicillin.
Two forms of IE include the subacute form (typically affecting those with preexisting
valve disease) and the acute form (typically affecting those with healthy valves).
The most common causative organisms of IE are Staphylococcus aureus and
The principal risk factors for IE are prior endocarditis, prosthetic valves, acquired
valvular disease, and cardiac lesions.
Vegetations, the primary lesions of IE, adhere to the valve surface or endocardium and
can embolize to various organs (particularly the lungs, brain, kidneys, and spleen) and to
the extremities, causing limb infarction.
The infection may spread locally to cause damage to the valves or to their supporting
structures resulting in dysrhythmias, valvular incompetence, and eventual invasion of the
myocardium, leading to heart failure (HF), sepsis, and heart block.
Clinical findings in IE are nonspecific and can include the following:
o Low-grade fever, chills, weakness, malaise, fatigue, and anorexia
o Arthralgias, myalgias, back pain, abdominal discomfort, weight loss, headache,
and clubbing of fingers
o Splinter hemorrhages (black longitudinal streaks) in the nail beds
o Petechiae (a result of fragmentation and microembolization of vegetative lesions)
in the conjunctivae, the lips, the buccal mucosa, and the palate and over the
ankles, the feet, and the antecubital and popliteal areas
o Osler’s nodes (painful, tender, red or purple, pea-size lesions) on the fingertips or
toes and Janeway’s lesions (flat, painless, small, red spots) on the palms and
o Hemorrhagic retinal lesions called Roth’s spots
o A new or changing murmur in the aortic or mitral valve
Definitive diagnosis of IE exists if two of the following major criteria are present:
positive blood cultures, new or changed cardiac murmur, or intracardiac mass or
vegetation noted on echocardiography.
Collaborative care consists of antibiotic prophylaxis for patients with specific cardiac
conditions before dental, respiratory tract, gastrointestinal (GI), and genitourinary (GU)
procedures and for high-risk patients who (1) are to undergo removal or drainage of
infected tissue, (2) receive renal dialysis, or (3) have ventriculoatrial shunts for management of hydrocephalus.
Drug therapy consists of long-term treatment with IV antibiotic therapy with subsequent
blood cultures to evaluate the effectiveness of antibiotic therapy.
Early valve replacement followed by prolonged (6 weeks or longer) drug therapy is
recommended for patients with fungal infection and prosthetic valve endocarditis.
Fever is treated with aspirin, acetaminophen (Tylenol), ibuprofen (Motrin), fluids, and
Complete bed rest is usually not indicated unless the temperature remains elevated or
there are signs of HF.
Overall goals for the patient with IE include (1) normal or baseline cardiac function, (2)
performance of activities of daily living (ADLs) without fatigue, and (3) knowledge of
the therapeutic regimen to prevent recurrence of endocarditis.
Patients and families must be taught to recognize signs and symptoms of life-threatening
complications of IE, such as cerebral emboli (e.g., change in mental status), pulmonary
edema (e.g., dyspnea), and HF (e.g., chest pain).
o Fever (chronic or intermittent) is a common early sign that the drug therapy is