The irregular pulse : its value in prognosis ; Stokes-Adams disease : report of a case / by John Hay.

  • Hay, John, 1873-1959.
Date:
1906
Catalogue details

Licence: In copyright

Credit: The irregular pulse : its value in prognosis ; Stokes-Adams disease : report of a case / by John Hay. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    were obtained with the metal receiver pressed more firmly on the neck. As a result of this increased pressure, the carotid pulse is dominant in the upper tracing, and the sphygmogram is typically arterial in character. Tlie wave a, representing the systole of the auricle, still persists, and bears the same relationship to the carotid pulse as in fig. 1; though, as a result of the increased pressure, it is much diminished in amplitude. We know that the muscular contraction during cardiac Tracing to show the normal or auricular type of venous pulse. The space E indicates in all the tracings the period of ventricular systole during which the semilunar valves are open, the sphygmic period. The wave a, preceding the period E, can only be due to the systole of the right auricle. The fall x is partly due to the diastole of the auricle causing a rush of blood out of the jugular veip.into the auri(^e, and partly to the change in position of the auriculo-ventricular grooV'e cauped by the ventricular systole.* “ The wave c is due to the impact-'of the -Carotid pulse. The space A repre^nts the a c interval and indicates the time “taken by the stimulus to pass from the auricle to the ventricle. It is normally.-j^ of a second. The time mariner records i of a second'. ’ This applies to ail the tracings. . . systole spreads like a wave'from the sinus of the auricles’over the auricles down on to tlie••'Ventricles. This is the normal sequence—auricles first, then-^ventricleB; but it is important to note that this sequence is not invariably followed. The auricles and ventricles sometimes contract simultaneously, or the ventricle may even contract before the auricle. Gaskell^ has pointed out, in his classical research on the contraction of the cardiac muscle, that the heart muscle * H. I. Douraa, De Analyse van hel phlehogravi. ® A. Keith, Hunterian Lectures, Lancet, 1904. »'W. H. Gaskell, “The Contraction of Cardiac Muscle,” Schafer's Text-book of Physiology.