The clinical syndrome is variable and spans a continuum between acute and subacute presentations.

Cardiac Manifestations

• Heart murmurs, particularly new or worsened regurgitant murmurs, are ultimately heard in 85% of pts with acute NVE.
• Congestive heart failure (CHF) develops in 30-40% of pts and is usually due to valvular dysfunction.
• Extension of infection can result in perivalvular abscesses, which in turn may cause fistulae from the aortic root into cardiac chambers or may burrow through epicardium and cause pericarditis.
• Heart block may result when infection extends into the conduction system.
• Emboli to a coronary artery may result in myocardial infarcts.

Noncardiac Manifestations

• Hematogenous bacterial seeding (e.g., to the spleen, kidneys, and meninges) can cause abscesses in noncardiac tissues.
• Arterial emboli of vegetation fragments lead to infection or infarction of remote tissues such as the extremities, spleen, kidneys, bowel, or brain. Emboli most commonly arise from vegetations >10 mm in diameter and from those located on the mitral valve. With antibiotic treatment, the frequency of emboli decreases from 13 per 1000 pt-days during the first week of infection to 1.2 per 1000 pt-days during the third week.
• Neurologic complications are seen in up to 40% of pts and include embolic stroke, aseptic or purulent meningitis, intracranial hemorrhage due to ruptured mycotic aneurysms (focal dilations of arteries at points in the artery wall that have been weakened by infection or where septic emboli have lodged) or hemorrhagic infarcts, seizures, encephalopathy, and microabscesses.
• Renal infarcts cause flank pain and hematuria without renal dysfunction.
• Immune complex deposition causes glomerulonephritis and renal dysfunction.
• Peripheral manifestations such as Osler's nodes, subungual hemorrhages, Janeway lesions, and Roth's spots are nonsuppurative complications seen in prolonged infection and are now rare because of early diagnosis and treatment.

Tricuspid Valve Endocarditis
This condition is associated with fever, faint or no heart murmur, and prominent pulmonary findings such as cough, pleuritic chest pain, and nodular pulmonary infiltrates.

Health Care-Associated Endocarditis
Manifestations depend on the presence or absence of a retained intracardiac device. For example, transvenous pacemaker lead-related endocarditis may be associated with generator pocket infection and results in fever, minimal murmur, and pulmonary symptoms due to septic emboli.

Paravalvular Infection
This condition is common in PVE, resulting in partial valve dehiscence, regurgitant murmurs, CHF, or disruption of the conduction system.