148 PHENOMENA OF ANACROTISM. 



is longer than the duration of the elastic vibration, for example in cases of dilatation 

 and hypertrophy of the left ventricle. This is illustrated in Fig. 54, A, which 

 represents the radial curve from a patient with contracted kidney. Under such 

 conditions the great mass of blood propelled with each systole requires an ab- 

 normally long time to effect distention of the already greatly distended artery. 



2. When the distensibility of the arterial tube is diminished, a quantity of 

 blood, which in itself is not increased, will require a longer time to effect distention 

 of the walls. Such a condition is observed in old persons whose arterial walls 

 have acquired great rigidity. As cold tends to contract the arteries, so that they 

 are reduced to a condition of diminished distensibility, it is not difficult to under- 

 stand that the pulse is likely to assume the characters of anacrotism within an 

 hour after a cool bath (Fig. 54, D). The carotid pulse in the rabbit becomes 

 anacrotic after irritation of the vasomotor nerves. 



3. When, owing to blood-stasis as a result of extreme retardation of the blood- 

 current, such as occurs in paralyzed limbs, the quantity of blood injected into 

 the arterial system with each systole is incapable of effecting normal distention 

 of the arterial wall, anacrotic elevations are seen in the sphygmographic tracing 

 (Fig. 54, B). 



4. When, after ligation of an artery, the blood can enter the peripheral segment 

 through the relatively small collateral circulation only within a comparatively 

 long time, the distention of the arterial coat will be marked by several elastic 

 vibrations. Wolff succeeded in producing these in tracings from the radial artery 

 not yet possessing distinct anacrotic characters by applying compression above 

 the brachial artery and thus retarding the flow of blood into the radial artery. 

 Also in cases of aortic stenosis, a condition in which the blood can enter the 

 arteries but slowly through the aorta, anacrotism has frequently been observed 

 (Fig. 54, C). 



FIG. 54. Anacrotic Tracings from the Radial Artery: a a, anacrotic notches. 



In the same category belongs also the phenomenon of the so-called recurrent 

 pulse. When the radial artery is compressed at the wrist, the pulse at once 

 reappears at a point situated peripherally from the site of compression, being 

 transmitted by the arterial palmar arches. The tracing from such a pulse ex- 

 hibits anacrotism and in addition (as is readily understood) a diminished 

 recoil-elevation, as well as more numerous and more distinct elasticity- 

 elevations. 



5. A peculiar form of anacrotism is observed in connection with high grades 

 of aortic insufficiency. The most characteristic sign of this lesion is the permanent 

 patency of the aorta. Hence, not only will waves be propagated in the root of 

 the aorta by the movements of the ventricle, but also the contraction of the 

 hypertrophied left auricle will cause a wave-movement in the ventricular blood 

 that is at once propagated through the patulous orifice of the relatively flaccid 

 aorta and its branches. This is followed by the true pulse- wave, which is pro- 

 duced by the contraction of the ventricle. It is obvious that not only is the 

 wave produced by the contraction of the auricle smaller, but it also precedes 

 the principal wave. The peculiarity of the anacrotism in sphygmographic tracings 

 from large vascular trunks, taken from cases of insufficiency of the aortic valves, 

 is that the auricular wave occurs before the ventricular wave in the ascending 

 limb. This anacrotism manifests itself in curves taken from the larger vascular 

 trunks because the wave, in itself but small, gradually disappears as it advances 

 peripherally toward the smaller vessels. 



Fig. 55, I, represents a sphygmographic tracing from the carotid of a man. 

 It exhibits an abrupt ascending limb, caused by the force of the hypertrophied 

 heart. At the apex of the curve there appear quite constantly two sharp inden- 

 tations, the more anterior of which, having a narrower base, requires less time for 



