Slide 53.Subacute bacterial endocarditis (SBE), Heart

A. Brief Descriptions

  1. Infective endocarditis (IE): colonization of heart valves or mural endocardium by micro-organisms leading to the formation of friable vegetations laden with organisms.

B. Gross Findings

  1. Friable , bulky bacteria-laden vegetations most commonly on the heart valves which is usually not destructed in SBE.

C. Micro Findings

  1. the valve leaflet covered at its tip by pink staining vegatations containing small colonies of blue-purple staining bacteria.

  2. Vegetation: be composed of fibrin、inflammatory cells and organisms.

  3. No apparent bacterial destruction of the valve.

D. Others:

  1. 傳統上依照臨床表現分成Acute endocarditis and subacute endocarditis.

    • Acute endocarditis: 之前通常是Normal heart valve,感染到Highly virulent organism,具有High mortality rate.

    • Subacute endocarditis: 之前通常是Abnormal heart valve,併發Low virulent organism感染。

  2. 事實上,要明確劃分Acute endocarditis and subacute endocarditis,有時並不容易,因為在臨床上和型態學上,這兩種疾病的變化是連續的。

E. Reference

  1. Robbins Pathologic Basis of Disease, 6th ed.  P.572-576.




Fig. 53-1 (LP)A vegetation arisen from valve; note myocardium in the left lower corner.




Fig. 53-2 (LP)





Fig. 53-3 (LP)Pinkish stained vegetation with minimal inflammation; note densely inflammatory infiltrate in the valve leaflet.




Fig. 53-4 (LP)Blue purple color of bacterial clumps (colonies) in vegetation.