Physiology and biochemistry in modern medicine (1918) (14781319865)
Zusammenfassung
Identifier: physiologybioche00macl (find matches)
Title: Physiology and biochemistry in modern medicine
Year: 1918 (1910s)
Authors: Macleod, John James Rickard, 1876-1935 Pearce, R. G. (Roy Gentry), 1884-
Subjects: Physiology Biochemistry
Publisher: St. Louis : Mosby
Contributing Library: Columbia University Libraries
Digitizing Sponsor: Open Knowledge Commons
Text Appearing Before Image:
** -v* Tt*,y. k v k k I k k k i=B W §5 «-c -» (rt ^> K k 4-^ ^ M -* Iig. 101.—Premature beats (extrasystoles) ventricular in origin at PB. Compare the duration ofthe intervals marked A and B with those marked C and D. (From E. P. Carter.) may be due to: (1) premature auricular or ventricular contractions;(2) the occasional occurrence of dropped beats (a failure of ventricularresponse) ; or (3) a high degree of heart-block with a wide variation inthe ventricular response. The important point to note here is that, nomatter how irregular such a tracing may appear, if the irregularity re-peats itself it can not be due to auricular fibrillation.
Text Appearing After Image:
Fig. 102.—Paroxysmal tachycardia. The paroxysms start at x£ following normal beats andlasting for seven beats. The clue to a, which falls with v after the first premature contrac-tions, is found in the initial beat of the new rhythm. (From E. P. Carter.) Paroxysmal Tachycardia.—When the rate of a regular pulse is sud-denly altered but the change in rate bears a simple ratio to the previousrhythm, the change may be due to (1) premature ventricular contrac-tions which do not reach the radial, or (2) to the sudden development )()I.VS;-HV(JM()(iKA.MS 279 of a two-iii-one heart-block. When on the other hand, there is no exactratio between the slow and the rapid rate, the change is due to the sud-den appearance or disappearance of paroxysmal tachycardia. Theparoxysms during which the auricle is beating very rapidly may last fora variable time, such attacks persisting off and on for hours or even days.The tracing in such a case is given in Fig. 102. ^MwV V^