

CHAPTER XXXII 



CLINICAL APPLICATIONS OF CERTAIN PHYSIOLOGICAL 

 METHODS (Cont'd) 



POLYSPHYGMOGRAMS 



(Revised by DR. N. B. TAYLOR) 



For purposes of more precise study and description of polysphygmo- 

 grams and in order that the events in the different pulse tracings (jug- 

 ular, carotid, apex beat, and radial) may be correlated accurately with 

 one another, in regard to time, the following method of standardization 

 has been employed (see Fig. 95). The tracings have been superimposed, 

 accurately, so that the commencement of each is in the same vertical 

 line (i.e., all the curves are made to start, as it were, at the same in- 

 stant). Perpendicular lines (6 in number) have then been drawn through 

 the tracings at certain important and easily recognizable points. Since 

 the tracings commence together and the intersecting lines are perpendic- 

 ular to them it is clear that the points in the different curves which are 

 cut by a given line will be synchronous, for example, line 2 cuts the 

 tracing of the apex beat at the commencement of its upstroke and falls 

 in the case of the venous tracing near the summit of the "A" wave. 

 These events in the respective curves, consequently, must be of simul- 

 taneous occurrence. 



In the taking of polysphygmograms the following technique is usu- 

 ally employed: 



Venous Pulse Tracings. The subject is directed to lie down with his 

 head slightly raised by a cushion and turned toward the right side. An 

 open tambour (one having no rubber membrane) is placed above the 

 inner end of the clavicle on the right side of the neck, that is, immedi- 

 ately overlying the jugular bulb. 



Though the features of a normal and typical venous pulse tracing may be 

 recognized by inspection alone, it is very often impossible in diseased 

 conditions to identify the different waves of the curve without the use 

 of a standard for comparison. For this purpose a simultaneous tracing 

 is taken from an artery, the features of which (primary and dicrotic 



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