On the interpretation of cardiographic tracings, and the evidence which they afford as to the causation of the murmurs attendant upon mitral stenosis / by A. L. Galabin, M.D.

  • Galabin, Alfred Lewis, 1843-1913.
Date:
[cbetween 1800 and 1899?]
Catalogue details

Licence: Public Domain Mark

Credit: On the interpretation of cardiographic tracings, and the evidence which they afford as to the causation of the murmurs attendant upon mitral stenosis / by A. L. Galabin, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    healthy hearts this is often essential for success. But with many persons it is a condition very difficult to secure, especially when they are suffering from thoracic distress, and when the heart is much hypertrophied it becomes of less importance, because then the amplitude of the cardiac move- ment is much greater in proportion to that of the respiratory curve. In many cases also it is of interest to obtain the combined curve, for it is often found that an exact rhythm exists between the cardiac and respiratory movements, each respiration comprising precisely two, three, or four pulsations. Instances of this are shown in PI. II, fig. 5, and PI. Ill, fig. 18. In such cases, especially when there is much dyspnoea, the beats of the heart rapidly diminish in vigour while the breath is held, and sometimes lose their characteristic features. If, however, the combined curve be procured, it is often found that, if the respiration be not extremely hurried, a single perfect revolution of the heart is shown during the pause which follows the end of expiration. Such a pause extends over about one and a half of the two beats shown in PI. Ill, fig. 3. The majority of the tracings upon which the present paper is founded were taken with the cardiograph here described. Some, however, were obtained with a sphygmograph, which has a similar adjustment for varying the amplitude given to the trace, means being taken in its application to prevent the framework touch- ing the chest within the range of the cardiac impulse. Its action is therefore practically identical with that of the cardiograph, except as regards the slower motion of the clockwork, which occupies eight seconds for the whole transit, the corresponding interval for the cardiograph being five and a half seconds. Tracings taken with this instrument are marked B in the explanation. The interpretation of the cardiac trace necessarily involves far greater difficulties than that of the arterial pulse. While the latter denotes only the variations of blood pressure, there are at least four conditions of the heart which may affect the cardiac curve; first, its firmness or relaxation; secondly, its state of repletion; thirdly, its locomotion as a whole; and, fourthly, changes in its shape, or the direction of its axis