Endocarditis II: Clinical Features of Infective Endocarditis

Infective endocarditis typically begins insidiously with general symptoms including fever, chills, weakness, malaise, fatigue, and weight loss. These nonspecific symptoms reflect the systemic nature of the infection and the body's inflammatory response to bacterial presence in the bloodstream and heart tissue, often making the disease easy to mistake for other illnesses initially.

Splinter hemorrhages are black, longitudinal streaks appearing under nail beds, caused by small clots or infected material fragments that embolize from the heart. Petechiae are small red or purple spots from minor hemorrhages appearing on the conjunctivae, lips, buccal mucosa, palate, ankles, feet, and antecubital and popliteal areas, indicating widespread microvascular involvement.

Osler's nodes are tender, red or purple, pea-sized lesions on fingertips or toes resulting from immune complex deposition in the skin. Janeway lesions are non-tender, small, erythematous macules on palms and soles caused by septic emboli. Both are hallmark signs of infective endocarditis but differ in tenderness, location, and underlying pathophysiology.

Roth's spots are hemorrhagic retinal lesions with white or pale centers observed during eye examination. They underscore the systemic embolic phenomena associated with infective endocarditis, representing septic emboli reaching the retinal vasculature and causing characteristic hemorrhagic lesions with pale centers.

In tricuspid infective endocarditis, murmurs may be absent because right-sided heart sounds are too low to be heard during standard cardiac auscultation. This makes diagnosis challenging, as the absence of an audible murmur does not exclude endocarditis, particularly when infection affects the tricuspid valve.

Cardiac involvement often includes development of a new heart murmur or changes in an existing one due to infection damaging heart valves and causing turbulent blood flow. A new or changing murmur in the context of systemic infection strongly suggests infective endocarditis and warrants further investigation through clinical features and diagnostic tests.

As infective endocarditis progresses, specific vascular signs become apparent beyond initial general symptoms. These include splinter hemorrhages, petechiae, Osler's nodes, Janeway lesions, and Roth's spots, collectively reflecting the systemic embolic phenomena and widespread microvascular involvement characteristic of the advancing disease process.