Endocarditis

Endocarditis develops most commonly on the mitral valve, closely followed in descending order of frequency by the aortic valve, the combined mitral and aortic valve, the tricuspid valve, and, rarely, the pulmonic valve. The common denominator for adherence and invasion is nonbacterial thrombotic endocarditis, a sterile fibrin-platelet vegetation. This critical mass is the result of bacterial clumping produced by agglutinating antibodies. In acute IE, the thrombus may be produced by the invading organism (i.e., S aureus) or by valvular trauma from intravenous catheters or pacing wires (ie, NIE/HCIE).