Heart-beat and pulse-wave / by C.S. Roy and J.G. Adami.

Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Heart-beat and pulse-wave / by C.S. Roy and J.G. Adami. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    19/88 (page 165)
    there are no valves at the openings of the large veins into the auricles, such as would allow of the auricular pressure raising that within the ventricle to any great extent; and partly to the readiness with which the ventricular walls expand and accommodate themselves when more blood enters during the period of diastole. As can be seen from the tracings C and D, Fig. 7, the commencement of the systolic rise of pressure is sometimes abrupt. The first slow rise, upon which we have already dwelt to some extent, may, we imagine, be safely as- sumed to be due (when present) to the elastic stretching of the musculi papillares; these, as we have mentioned in Section II., are passively elongated previous to their contraction It Fig. S. Intraventricular pressure-curve from left ventricle of horse (Marey) will be remembered that we have shown that the contraction of the papillary muscle commences after that of the ventricular wall. After the maximum pressure is reached at c, the pressure falls to a varying extent to the point c', forming afterwards a more or less rounded shoulder between c' and e. The height of the superposed wave c above the shoulder (c' to e) may vary greatly under different conditions, the wave may even appear on the ascending limb of the curve, as in tracing D, Fig. 7; or, as can be seen in B and C, Fig. 7, taken after the administration of a medicinal dose of strophanthus, this wave may rise high above the summit of the rest of the pressure