CHAPTER XXXI 



CLINICAL APPLICATIONS OF CERTAIN PHYSIOLOGICAL 

 METHODS (Cont'd) 



POLYSPHYGMOGRAMS 



Venous Pulse Tracings. In taking polysphygmograms, the following 

 technic is usually followed: The observed person is directed to lie down 

 with his head slightly raised by a cushion and bent to the right side. The 

 receiver (thistle funnel) is placed over the jugular bulb on the right side 

 of the neck. This lies immediately above the inner end of the clavicle. 

 The style of the recording tambour is adjusted to write with a minimal 

 amount of friction on the recording surface. Since a venous pulse tracing 

 can not be interpreted without a simultaneous tracing from an artery, 

 the button of a receiving tambour is also adjusted over the radial artery 

 and the style of its recording tambour arranged so as to write on the 

 drum in the same perpendicular as the style of the venous tambour. 



Tracings should be taken with the recording surface at a moderate 

 speed and before disturbing the relative positions of the writing points, 

 they should be caused to inscribe vertical marks (with recording sur- 

 face stationary) at various parts of the tracings. These alignment marks 

 permit of accurate comparisons between the curves. A time tracing 

 (% sec.) should always be taken simultaneously. The polysphygmograph 

 is shown in Fig. 95. 



To interpret the venous curve, a vertical mark is made on the arterial 

 pulse tracing corresponding to the beginning of the pulse upstroke. If 

 this is done on the radial pulse tracing, one-tenth of a second is measured 

 in front of it, and a vertical mark made to allow for the time lost in prop- 

 agation of the pulse from the heart to the radial artery. 



This line 3 (corrected in case of radial pulse) corresponds to the be- 

 ginning of the sphygmic period of ventricular systole i. e., to the open- 

 ing of the semilunar valves. The distance is measured from it to the 

 nearest alignment mark and transferred to the venous tracing, using 

 the corresponding mark. This will fall at the beginning of the small 

 wave (c), w r hich is due to the bulging into the auricles of the closed 

 auriculoventricular valves. (Fig. 96.) 



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