Outlines of general pathology / by George Freckleton.

  • Freckleton, George.
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of general pathology / by George Freckleton. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    places ;—1st. In the whole left side of the chest; 2dly. In the right side, from the axilla to the epigastrium ; 3dly. In the posterior part of the left side; and 4thly, but much more rarely, In the posterior part of the right side. The intensity of the sound is progressively less in the same order. Several circumstances independent of affections of the heart may, however, produce similar effects ? thus, hepatiza- tion of the lungs, or cavities existing in them, and formed by the softening of tubercles, &c, increase the extent of space over which the pulsations are heard. Many accidental causes, also, may pro- duce a temporary increase, as nervous agitation, a high degree of fever, palpitations, and anything, in short, which increases the fre- quency of the pulse. The extent of the pulsations of the heart is in direct proportion to the thinness of its walls; the thinner they are, the more exten- sively are the pulsations heard, which become circumscribed in proportion to any increase in their thickness. The pulsations of the heart give to the ear of the observer a degree of percussion, or of elevation, which Laennec terms shock, and this may be perceived by aid of the cylinder when it is imper- ceptible to the hand. The intensity of this shock is generally in an inverse proportion to the extent of the pulsations, and in a direct proportion to the degree of thickness of the walls of the ventricles. It is scarcely observable in a healthy individual; but any exertions, as walking or running, nervous agitation, palpitations or fever, generally increase it in persons whose hearts have rather thick parietes, and, of course, in those who have a disposition to hyper- trophy ; in which disease, it is often so considerable as to raise very sensibly the head of the observer, and even to communicate to the ear a disagreeable shock, and the more considerable the hypertrophy, the more slow is the pulsation. When it is very great, says Laennec, it appears to go on progressively ; the heart seems in dilating to apply itself, at first, in a single point to the chest, then in its whole extent, when it immediately sinks again. Generally, the systole of the ventricles alone produces it; when occasioned by that of the auricles, it seems much deeper, and consists of a sort of trembling perceived at some depth in the me- diastinum, the heart appearing to withdraw itself from the ear. When the walls are thinner than usual there is no impulse, even when the pulsation is greatest. The quick motions of the heart, as observed in palpitation, produced by other causes than organic disease, differ from the shock of hypertrophy. For, in these, the heart appears to strike only with its point against the walls of the chest, producing a quick smart hard noise, like the blow of a ham- mer, while in the latter the ventricles seem to distend, and apply themselves to the walls of the chest in their whole extent, which yield to their pressure, and communicate to the ear a degree of elevation or raising proportionate to their force. The alternate contractions of the different parts of the heart may be heard distinctly by the cylinder. In the natural state this noise