142 VENOUS MURMURS. 



vessel, and seems to occur chiefly when the walls of a thin part of the vein lie close 

 to each other, so that the current must purl through it. It is clear that pressure 

 from without, or lateral pressure, as by turning the head to the opposite side, must 

 favour its occurrence. Its intensity will be increased when the velocity of the 

 stream is increased, hence inspiration and the diastolic action of the heart (both of 

 which assist the venous current) increase it. The erect attitude acts in a similar 

 manner. A similar bruit is sometimes, though rarely, heard in the subclavian, 

 axillary, thyroid, facial, innominate and crural veins, and superior cava. 



H Regurgitant Murmurs. On making a sudden effort, a murmur may be heard in the 

 crural vein during expiration, which is caused by a centrifugal current of blood, owing to the 

 incompetence or absence of the valves in this region. If the valves at the jugular bulb are not 

 tight, there may be a bruit with expiration {expiratory jugular vein bruit Hamernjk), or 

 during the cardiac systole (systolic jugular vein bruit v. Bamberger). 



IH Valvular Sounds in Veins. When the tricuspid valve is incompetent, during the ven- 

 tricular systole, a large volume of blood is propelled backwards into the venae cavae. The 

 venous valves are closed suddenly thereby and a sound produced. This occurs at the bulb or 

 dilatation on the jugular vein (v. Bamberger), and in the crural vein at the groin (N. Friedreich), 

 i.e., only as long as the valves are competent. Forced expiration may cause a valvular sound 

 in the crural vein. No sound is heard in the veins under perfectly normal circumstances. 



99. THE VENOUS PULSE PHLEBOGRAM. Methods. A tracing of the movements of 

 a vein, taken with a lightly weighted sphygmograph, has a characteristic form, and is called a 

 phlebogram (tig. 117). In order to interpret the various events of the phlebogram it is most 

 important to record simultaneously the events that take place in the heart. The auricular con- 

 traction (compare tig. 39) is synchronous with ab ; be, with the ventricular systole, during which 

 time the first sound occurs, whilst a b is a presystolic movement. The carotid pulse coincides 

 nearly with the apex of the cardiogram, i.e., almost simultaneously with the descending limb 

 of the phlebogram (Riegt I . 



Occasionally in healthy individuals a pulsatile movement, synchronous with the 

 action of the heart, may be observed in the common jugular vein. It is either 

 confined to the lower part of the vein, the so-called bulb, or extends farther up 

 along the trunk of the vein. In the latter case, the valves above the bulb are 

 insufficient, which is by no means rare, even in health. The wave-motion passes 

 from below upwards, and is most obvious when the person is in the passive 

 horizontal position, and it is more frequent on the right side, because the right vein 

 lies nearer the heart than the left. It is propagated more slowly than the arterial 

 pulse- wave. The venous pulse resembles very closely the tracing of the cardiac 

 impulse. Compare fig. 117, 1, with tig. 39. 



It is obvious that, as the jugular vein is in direct communication with the right 

 auricle, and as the pressure within it is low, the systole of the right auricle must 

 cause a positive wave to be propagated towards the peripheral end of the jugular 

 vein. Fig. 117, 9 and 10, are venous pulse-tracings of a healthy person with 

 insufficiency of the valves of the jugular vein. In these curves, the part a b 

 corresponds to the contraction of the auricle. Occasionally this part consists of two 

 elevations, corresponding to the contraction of the atrium and auricle respectively. 

 As the blood in the right auricle receives an impulse from the sudden tension of 

 the tricuspid valve, synchronous with the systole of the right ventricle, there is a 

 positive wave in the jugular vein in fig. 117, 9 and 10, indicated by b, c. Lastly, 

 the sudden closure of the pulmonary valves may even be indicated (e). As the 

 aorta lies in direct relation with the pulmonary artery, the sudden closure of its 

 valves may also be indicated (fig. 91, 9, at J). During the diastole of the auricle 

 and ventricle, blood flows into the heart, so that the vein partly collapses and the 

 lever of the recording instrument descends. 



Sinus and Retinal Pulse. The blood in the sinuses of the brain also undergoes a pulsatile 

 movement, owing to the fact that during cardiac diastole much blood flows into the veins 

 (Mosso). Under favourable circumstances, this movement may be propagated into the veins of 

 the retina, constituting the venous retinal pulse of the older observers (Hclfreich). 



Pathological Jugular Vein Pulse. The venous pulse in the jugular vein is far better marked 



