Bacterial endocarditis is an infection of the endocardium or the heart valves as a result of bacteremia. The etiology is likely due to common pathogens that affect individuals with risk factors. This disease may manifest in a subacute or acute form.
Patients with this type experience an insidious onset of nonspecific symptoms such as low-grade fever, fatigue, anorexia, weight loss, malaise, night sweats, chills, and arthralgia. These may persist for weeks to months .
The clinical picture of acute bacterial endocarditis consists of a sudden onset of fever  along with a rapid and aggressive course . Septic shock may occur in these critically ill individuals. The majority of patients will have a heart murmur.
Up to half of all patients will exhibit classic physical signs such as 1) petechiae, 2) splinter hemorrhages, 3) Osler's nodes, 4) Janeway lesions and 5) Roth's spots. The latter three are considered minor criteria used for diagnosis of bacterial endocarditis .
Notable vital sign findings include fever and tachycardia. The patient overall appears toxic and pale. Also, patients with CHF present with jugular vein distension and peripheral edema. Moreover, focal neurologic deficits occur in up to 40% of affected patients . Delirium and other mental status changes may be evident. Additionally, conjunctival hemorrhage may also be apparent.
The cardiac exam is a crucial component of the physical assessment as auscultation typically reveals the presence of a murmur. This may either be new or an exacerbation of a preexisting murmur. Other abnormal heart and lung sounds may include gallops, rales, pericardial rub, and pleural friction rub.
The clinical assessment should include a detailed history of the patient and the inquiry about risk factors such as congenital heart defects, history of the rheumatic disease, and the presence of prosthetic valves  as well as intravenous drug use (IVDU) .
The clinical presentation, history, and physical exam findings should raise suspicion for bacterial endocarditis. Further testing is necessary as described below. Also, the clinician must follow the Duke diagnostic criteria for endocarditis to establish the diagnosis .
The American Heart Association (AHA) recommends obtaining at least three blood cultures, of which the initial and final sets are drawn at least one hour apart . Furthermore, the samples should be retrieved from 3 different venipuncture sites. Very importantly, initiation of empiric antibiotic treatment should be postponed until after cultures are provided.
The workup further includes a complete blood count (CBC), complete metabolic panel (CMP), erythrocyte sedimentation rate (ESR), complement panel, coagulation studies, and rheumatoid factor (RF). These tests may reveal leukocytosis, anemia, elevated ESR, and positive RF. Also, urinalysis typically shows microscopic hematuria and may also depict red blood cell (RBC) casts.
The AHA also recommends the use of echocardiography to investigate the presence of valvular vegetations and annular abscess  and to evaluate the valvular and heart function overall. Specifically, transthoracic echocardiography (TTE) is the initial imaging modality performed in most individuals while transesophageal echocardiogram (TEE) is the study of choice for those with a cardiac implantable electronic device (CIED)  or prosthetic valves .
Note that a patient with manifestations suggestive of cerebral emboli should be evaluated with a head computed tomography (CT) scan  or magnetic resonance imaging (MRI) .