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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![obtained from the iiii])ii]se of the hypertrophied or dilated heart against the chest-walL A stethoscope with a small end-piece en- ables one to diflerentiate sounds and murmurs and to trace them to their source in a way that cannot be done by the ear placed against the pripcordia. Normal Heart-sounds.—The detection of murmurs is not the only object of auscultation. The heart-sounds themselves often afford as much, if indeed not more information than do bruits. Therefore, if one is to correctly interpret what he hears come from; the heart, he must be familiar with the characters of the nor- mal sounds of this organ. To this end he must know how they are produced,* and keep in mind what is going on within, during the portions of the cardiac cycle, at the time of the sounds and during the intervals of silence. If one listens at any point upon the cardiac area he hears two distinct sounds, known as the first and second sound respectively. Over either of the ventricles, in the neighbourhood of the apex, the accent falls on the first, which is longer, of a lower pitch, and more intense—that is, more booming than the second, which is, conversely, short, sharp, and clicking, having a valvular quality we say. Moreover, the ear detects two intervals or periods of silence, of which the shorter occurs during systole between the first and succeeding second sound. The longer, known as the pause, falls between the second and next ensuing first sound, dur- ing diastole. This succession of sounds and silences gives to the heart-sounds their peculiar rhythm, likened to the ticking of a clock. If now auscultation be made at the base of the organ, in the second interspace at either side of the sternum, it is perceived that the accent falls on the second sound, since this is the louder and clearer and higher pitched of the two. Their rhythm is, how- ever, the same as at the apex. Furthermore, it is generally per- ceived that the second sound is louder on one side of the sternum * It is common to speak of sounds, whether normal or abnormal, as produced within the heart or chest. Of course such phraseology is loose and not in accord- ance with the known laws of acoustics. Sounds are the auditory perception of waves imparted to the air by the vibration of structures within the thorax, the tissues serving as good condiictors of these vibrations. With this understanding of the mode of production of these acoustic phenomena, I shall, for the sake of convenience and the avoidance of circumlocution, speak of sounds as generated in the heart or chest.](https://iiif.wellcomecollection.org/image/b21229533_0037.jp2/full/800%2C/0/default.jpg)
