Are the alveolar septa normal in thickness?
Infective endocarditis occurs on previously damaged valves, e.g. in rheumatic heart disease, or it may occur on normal valves when the organisms are very virulent and can cause valve destruction. So the valves are either previously damaged by disease or are damaged by the endocarditis itself. By contrast, in nonbacterial thrombotic endocarditis the valve is normal in appearance.
