Arterio-Sclerosis, with Especial Reference to the Blood Pressure Changes in this Condition, and to the Use of the Sphygmometer for Determining the Pressure in Routine Practice. WILLIAM PORTER, JR., M.D., Hartford. Not very much that is new can be said of the morbid anatomy, etiology, symptoms, or course of these arterial changes, as they are usually seen, but perhaps a few words in regard to these matters are in order. The real point of interest hangs on the blood pressure changes, on the manner of estimating these changes, and on their practical importance in daily practice. Arterio-sclerosis consists of a degeneration of the media, with subsequently a compensating thickening of the intima. This thickening of the intima is due to a development of connective tissue between the endothelium and underlying elastic tissue. Degenerative changes, with areas of necrosis, may form in this connective tissue, with subsequent deposit of lime salts, and the formation of calcareous plaques, which may be either quite localized, or the whole artery may become a tube of bony hardness. Atrophy and degeneration of the muscle fibres of the middle coat occur, and are replaced by connective tissue, the larger arteries becoming weakened, and frequently dilating, while the thickening of the coats of the smaller arteries varies in degree, but may be sufficient to obliterate them entirely. The outer coat of the artery also undergoes fibrous changes, and becomes thickened. It is interesting to mention the experimental production of arterio-sclerosis in rabbits, by the use of adrenalin, as shown recently by the observations of Pearce, with a most careful study of the histologic changes. These sclerotic changes may be local, the so-called nodular form, or diffuse, and Osler and other writers make a division of the senile form, in which there is extreme degeneration of the media, usually accompanied with atrophic changes in the kidneys and liver, an interesting point being the greater frequency with which some arteries are affected than others. Babcock quotes the investigation of Thoma, showing that the ulnar and anterior tibial arteries are most often affected, the cerebral, internal carotid, and radial coming next, the brachial and external iliac the least freqently. Brooks, in a recent paper of great interest, shows how much more frequently than has been supposed, sclerotic changes in the smaller visceral vessels occur. Localized or nodular sclerosis is found most often in those arteries which turn frequently in their course or give off many branches. Thoma has shown the abdominal aorta to be the most frequently affected. Brooks classifies all cases as follows. First, those in which the larger vessels are involved, but not the smaller ones. Second, those cases in which smaller vessels are involved, but not the larger. Third, a class of cases in which the changes are only microscopic with the small visceral vessels especially involved. Doubtless in time, all these classes overlap each other. Sclerosis of the veins also occurs, especially in the portal vein, in cases of cirrhosis of the liver, and at times in the pulmonary veins, in some forms of heart disease. We shall see farther on, that involvement of the splanchnic region is frequent, and perhaps the most important of all. The anatomical and physiological integrity of every organ in the body depends directly on a normal supply of blood. It is at once obvious therefore, that with the development of those arterial changes, the organs, which they should supply, must suffer. Practically, the heart, brain, liver, and kidneys are the organs more frequently and seriously affected. In the heart, with involvement of the coronary arteries, come myocardial and endocardial changes. These myocardial changes, especially of the fibroid type, have a more important relation to coronary sclerosis, which, as an etiological factor, must never be overlooked. Especially is this true, in the cases where the sclerosis has taken the coronaries first, or at least very early, without there being much evidence in the |