ANACROTISM. 



147 



curve is anacrotic, and the dicrotic wave is diminished, while the elastic 

 elevations are increased. 



III. 



Anacrotic pulse-curves A, B, C, D, from the radial artery ; a, a, the anacrotic 

 notches; I., II., III., curves with anacrotic elevations a in insufficiency of 

 the aortic valves. 



(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. 62, 1., was 

 obtained from the carotid of a man suffering from well-marked insufficiency of the 

 aortic valves, with considerable hypertrophy of the left ventricle and left auricle. 

 The ascent is steep, caused by the force of the contracted heart. In the apex of 

 the curve are two projections, A is the anacrotic auricular wave, and V is the 

 ventricular wave. Fig. 62, II., is a curve obtained from the subclavian 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. 62 

 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 



