It is well known that in diphtheria the heart muscle and the nerves which control it are the seat of certain changes which more or less seriously disturb its function, and the clinical signs of circulatory disturbance at the height of the disease and during convalescence have been carefully observed by many authorities. Much less is known, however, of the after-effects of the poison of diphtheria on the heart.
Veronese1 says that lasting effects on the heart—ex-except a moderate hypertrophy—do not follow diphtheria.
Romberg2 has seen the mitral insufficiency present in convalescence in several cases last several months and then disappear.
Steffen3 reports a case of mitral insufficiency following diphtheria which has been under observation for over four and a half years, and which he considers not a case of relative insufficiency, but of genuine valvular disease.
Baginsky4 says that the disturbance of the heart in