Diseases of the heart and arterial system : Designed to be a practical presentation of the subject for the use of students and practitioners of medicine.
- Babcock, Robert H. (Robert Hall), 1851-1930
- Date:
- 1910
Licence: Public Domain Mark
Credit: Diseases of the heart and arterial system : Designed to be a practical presentation of the subject for the use of students and practitioners of medicine. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
884/888 page 856
![tion of the valves was followed l)v capillarv dilatation and a veritable eollapse of the pulse through reflex action of the vaso- motor centers. Then studying the arterial tracing he found that the collapse of the jjulse occurred during systole, and not diastole, as has always been believed. In short he demonstrated that the collapse is of vasomotor origin and due to free systolic outflow into tlie capillaries, and not at all to regurgitation. This con- clusion was corroborated by the finding that whenever he inter- fered with escape of blood into the capillaries—e. g., by compres- sion of the abdouiinal aorta—he abolished the collapsing character of the pulse, although this manipulation should at the same time have increased the regurgitation. Tn this connection also it may be stated that the production of aortic regurgitation failed to raise systolic blood })ressure, but did lower the diastolic pressure, which, together with the capillary dilatation, is ^ conservative effort on the part of nature, since it lessens intraventricular pressure and also regurgitation. That the facts thus Ijriefly stated must possess both prognostic and therapeutic importance goes without saying. So long as the left ventricle is equal to the development and maintenance of in- creased tonus, and the elastic arterioles can res]iond to the vaso- dilatiug stiuiulus so as to pcruiit ready flow into the capillaries, compensatory liy])ertro]ihy jjersists and symptoms are nil. Hence the perfect adjustuient of the heart seen in the 3'oung in whom the lesion is the result of endocarditis. In those, on the other hand, in whom the aortic valve leaks as a part of a general arterio- sclerosis which by invasion also of the coronaries has led to myo- cardial degeneration, both increased ventricular tonus and a free systolic outflow into the capillaries are wanting or but poorly maintained. Hence symptoms are apt to appear early, and when once manifest to persist, or increase in spite of treatment, and sudden death is the rule. Therapeutically two suggestions arise: (1) Since digitalis con- stricts tlie arterioles it should be administered cautiously and in conjunction with vasodilators, or, instead, strophanthus should be the drug relied upon when cardiac inadequacy appears. (2) Ni- trite of sodium or some other equally eflicient vasodilator is called for, tlieoretically at least, wlicu the colla))sing character of the |)ulse is not well iiiai'kcd, aud in the sclerotic type of the disease, should always be pi-cscrilKMl.](https://iiif.wellcomecollection.org/image/b21229533_0884.jp2/full/800%2C/0/default.jpg)
