no 



INFLUENCE OF RESPIRATION ON PULSE-CURVE. 



stimulates the arteries, so that they become less extensile. Within one hour after a tepid bath, 

 the pulse assumes the anacrotic form (tig. 90, D) (O. v. Licbig). 



(3) When the blood stagnates in consequence of great diminution in the velocity of the 

 blood-stream, as occurs in paralysed limbs, the volume of blood propelled into the artery at 

 every systole no longer produces the normal distension of the arterial coats, and anacrotic 

 notches occur (tig. 90, B). 



(4) After ligature of an artery, when blood slowly reaches the peripheral part of the vessel 

 through a relatively small collateral circulation, it also occurs. If the brachial artery be com- 

 pressed so that the blood slowly reaches the radial, the radial pulse may become anacrotic. 

 It often occurs in stenosis of the aorta, as the blood has difficulty in getting into the aorta (fig. 

 90, C). 



Recurrent Pulse. If the radial artery be compressed at the wrist, the pulse- 

 beat reappears on the distal side of the point of pressure through the arteries of 

 the palm of the hand (Janand, Neidert). The curve is anacrotic, and the dicrotic 

 wave is diminished, while the elastic elevations are increased. 



(5) A special form of anacrotism occurs in cases of well-marked insufficiency of the aortic 

 valves. Practically, in these cases, the aorta remains permanently open. The contraction of 

 the left auricle causes in the blood a wave-motion, which is at once propagated through the 

 open mouth of the aorta into the large blood-vessels. This wave is followed by the wave caused 

 by the contraction of the hypertrophied left ventricle, but of course the former wave is not so 

 large as the latter. In insufficiency of the aortic valves, the auricular wave occurs before the 

 ventricular wave in the ascending part of the curve. The auricular is well marked only in the 

 large vessels, for it soon becomes lost in the peripheral vessels. Fig. 91, I, was obtained from 



H. III. 



Fig. 91. 

 1., 11., III., curves with anacrotic elevations a, in insufficiency oi the aortic valves. 



the carotid of a man suffering from well-marked insufficiency of the aortic valves, with con 

 siderable hypertrophy of the left ventricle and left auricle. The ascent is steep, caused by the 

 force of the contracting heart. In the apex of the curve are two projections ; A is the anacrotic 

 auricular wave, and V is the ventricular wave. Fig. 91, II, is a curve obtained from the sub- 

 clavian artery of the same individual. In the femoral artery the auricular projection is only 

 obtained when the friction of the writing-style is reduced to the minimum, and when it occurs 

 it immediately precedes the beginning of the ascent (fig. 86, III, a). The pulse-curve, in cases 

 of aortic insufficiency, is also characterised by (1) its considerable height ; (2) the rapid fall 

 of the lever from the apex of the curve, because a large part of the blood which is forced into 

 the aorta regurgitates into the left ventricle when the ventricle relaxes ; (3) not unfrequently a 

 projection occurs at the apex, due to the elastic vibration of the tense arterial wall ; (4) the 

 dicrotic wave (R) is small compared with the size of the curve itself, because the pulse-wave, 

 owing to the lesion of the aortic valves, has not a sufficiently large surface to be reflected from 

 (ng. 86). The great height of the curve is explained by the large amount of blood projected 

 into the aortic system by the greatly hypertrophied and dilated ventricle. 



74. INFLUENCE OF RESPIRATION ON THE PULSE-CURVE. The 



respiratory movements influence the pulse (1) in a purely physical way. Stated 

 broadly, the blood-pressure rises during inspiration and falls during expiration, 

 but when we consider the effect on the pulse-curve, it is found that it varies with 

 the depth, rapidity, and ease of respiration ; (2) the respiratory movements are 



