Diseases of the heart and arterial system : Designed to be a practical presentation of the subject for the use of students and practitioners of medicine.
- Babcock, Robert H. (Robert Hall), 1851-1930
- Date:
- 1910
Licence: Public Domain Mark
Credit: Diseases of the heart and arterial system : Designed to be a practical presentation of the subject for the use of students and practitioners of medicine. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
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![Reduplication of the First Sound.—Under certain conditions, as that of abnormal blood-pressure within one or the other ventricle, there is heard not a single first sound, but a reduplication or split- ting of this sound. This abnormality is less frequently perceived than is doubling of the second sound, and is equally difficult of satisfactory explanation. Two main theories are advanced to ac- count for it. One of these finds its causation in a hemisystole, by which is meant the separate and independent contraction of the two ventricles. Although there have been recorded a few cases in which highly competent and careful observers believed they de- tected such hemisystole, still it is so at variance with the physiol- ogy of the cardiac action to suppose the ventricles can fail to syn- chronize in their systoles that many authors are not willing to accept this explanation. The other theory assumes that the two components of the first sound in one or the other side of the heart do not fall together, but are separated by a brief yet distinct in- terval of time, so that to the ear the first sound over that ventricle gives the impression of splitting or reduplication. One or the other constituent of the sound is generated either too soon or too late to synchronize with the other. As the phenomenon occurs when blood-pressure in one of the ventricles is too high, and as under these conditions the cardiac wall has lost its normal tonicity, it seems reasonable that the tension into which the valves are thrown and the contraction of the heart-wall should not be per- fectly simultaneous. Sewall argues that the cause of the redupli- cation lies in the failure of the papillary muscles to contract at their proper time, their contraction, and hence the note of valve- tension, occurring either before or after that of the ventricular wall. Whatever l)e the true explanation of this phenomenon, its occurrence betokens excessive, and it may be dangerous, increase of pressure in that ventricle, to which the reduplication can be traced. It may be audible over either half, and I recall a case of mitral regurgitation in which this doubling appeared in the right ventricle only when the patient assumed the recundK'nt ])()stiire. It is not sehhtiii present over the left ventricle in cases of chronic nephritis, and then betokens (hingerous excess of blood-pressure in tlu! arterial system, and, secondarily, within the left ventricle. Gallop or Canter Rhythm.—A ithciioiiienon, sometimes ob- served and due to the interpolation of a third sound (which, ac-](https://iiif.wellcomecollection.org/image/b21229533_0042.jp2/full/800%2C/0/default.jpg)
