Heart hurry : a clinical study / by Edward Blake.

  • Blake, Edward T. (Edward Thomas), 1842-1905.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Heart hurry : a clinical study / by Edward Blake. Source: Wellcome Collection.

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    of tight lacing, may be due to the mere physical pressure of a distended stomach or colon, encountering perhaps a temporarily dilated heart. Those instances of true tachy¬ cardia, on the other hand, which, occurring once, run a definite course and go, to return no more, are probably due to neuritis of the pneumogastric or of the vagal nucleus in the medulla oblongata. They are not of the nature of vague and transcendental phenomena, known sometimes as “ irritation.” Whilst they may be at times purely “ reflex,” they may also be due to definite inflammations of the fibres of the vagus and these are doubtless of toxic origin. There are two well-marked types of vagal neuritis: (a) ascending, (b) descending. Ascending Type.—This is associated with three patho¬ logical conditions, which may exist either separately or in combination. 1. Myocarditis. 2. Inflammation of the membranes connected with the heart. 3. Aortitis. Descending Type.—In cases of deep-seated abscess, more especially of pulmonary purulent depots, as in tuberculosis and pneumonic abscess, we get temporary tachycardia. In these cases it is possible that the inhibitory function of the vagus is suspended by the paralysing action of the toxines of pus on the vagal nuclei. There is a sedative poison acting for a time on the floor of the fourth ventricle. The actions of tea and of tobacco are probably to be explained in this way. Some of the cases of menstrual, pregnant and puerperal palpitation have a similar mechanism : whilst others again are a product of dilated stomach. An excellent example of acute descending neuritis is afforded by diphtheria, when it terminates in death with lung complications. The toxic inflammatory change may descend by the pharyngeal branches of the pneumogastric to the heart, setting up myocarditis, followed by softening and then by dilatation. It may also descend to the pul¬ monary vagal filaments, causing oedema of the lung bases,