Infective endocarditis: a changing disease. II.

I have chosen for the subject of this Croonian lecture in fective endocarditis in its subacute or chronic forms and have reverted to the original term rather than bacterial en docarditis as the disease may also be caused by rickettsiae, histoplasmas, fungi, and possibly viruses. This disease, al though not common, has always had a fascination for the clinician, morbid anatomist, and bacteriologist, and I can not do better than follow the precept of Osier,1 who, in his Goulstonian lecture on malignant endocarditis to the College in 1885, stated: is of use from time to time to take stock, so to speak, of our knowledge of a particular disease, to see exactly where we stand in regard to it, and to inquire to what conclusions the accumulated facts seem to point, and to ascertain in what direction we may look for fruitful investi gations in the future. Before this there were many descrip tions in the literature of vegetative or ulcerative endocardi tis, but Osier first showed clearly that these cases could be separated into two groups?septic endocarditis, which we now call acute, where there was an obvious septic focus with septicaemia and infected infarcts, and so-called primary en docarditis, where the source of infection was not obvious, infarcts did not suppurate, and the disease ran a more chronic course. Between 1885 and 1909 the infective nature of this type of chronic endocarditis was established with recovery of or ganisms, usually streptococci of low virulence, from the vegetations and blood stream, and it was realized that the disease affected patients with either chronic valvular disease or congenital malformations of the heart. The clinical fea tures of the disease also became better recognized and were reviewed by Glynn2 in his Lumleian lectures of 1903.