THE PULSE. 475 



waves is variously modified in different parts of the system by the 

 reflected waves from different peripheral regions. 



Anacrotic Waves. As was said above, the anacrotic limb under 

 normal conditions shows no secondary waves. Under pathological 

 conditions, however, a secondary wave more or less clearly marked 

 may appear, as is shown, for instance, in the tracing given in Fig. 

 200. Such waves are recorded in cases of stiff arteries or stenosis 

 of the semilunar valves. In the normal individual an anacrotic 

 pulse may be obtained, according to von Kries,* by raising the 

 arm. He believes that in this position the reflection of the pulse 

 wave from the periphery is favored, and that the anacrotic wave is 

 simply a quickly reflected wave. It is possible that the same 

 explanation will hold for its appearance under pathological con- 

 ditions. 



Fig. 200. Anacrotic pulse from a case of aortic stenosis (Mackenzie): b, The anacrotic 



wave. 



Characteristics of the Pulse in Health and in Disease. 



By mere palpation the physician obtains from the pulse valuable 

 indications concerning the heart and the circulation. The fre- 

 quency of the heart beat is at once made evident, so far at least as 

 the ventricle is concerned. One may determine readily whether 

 the frequency is above or below the normal, whether the rhythm 

 is regular or irregular. By the same means one can determine 

 whether the pulse is large (pulsus magnus) or small (pulsus parvus), 

 whether the wave rises and falls rapidly (pulsus celer) as happens 

 in the case of insufficiency of the aortic valves, or whether in one 

 phase or the other it is more prolonged than normal (pulsus tardus). 

 It seems obvious, however, that a more satisfactory conclusion may 

 be reached in all such cases by obtaining a sphygmographic record. 

 In the works devoted to clinical methods numerous such sphygmo- 

 grams are described. By mere pressure upon the artery one can 

 determine also approximately whether the blood-pressure is high 

 or low, and a similar inference may be drawn from the character 

 of the sphygmogram; but since the introduction of the sphygmo- 

 manometer (p. 453) it seems evident that this instrument must be 

 appealed to whenever the determination of blood-pressure is a 

 matter of importance. 



Venous Pulse. Under usual conditions the pulse wave is lost 



* Von Kries, " Studien zur Pulslehre," 1892. 



