Jugular venous pulse (1957) Pt. 2 of 4

the amplitude of all the waves increases during inspiration cervical Venus pulsation ceases when the jugular veins are compressed to the root of the neck light pressure of the finger against the root of the external jugular vein distends the upper part of the vessel on removing the finger the vein collapses to the level of the mean jugul venous pressure Sir Thomas lewiis pointed out that the most satisfactory reference point from which to measure the Venus pressure was the sternal angle because this was about 5 cm above the center of the right atum in both horizontal and vertical positions with reference to the sternal angle the Venus pressure swings around a mean level of about- 2 cm in the horizontal position but the range is considerable indeed in this normal subject the maximum systolic level which happens to be a is plus 3.5 CM let us now look at some abnormalities of the Venus pulse a giant a wve abrupt and collapsing in quality and measuring between 6 and 15 mm of mercury above V is usual in tricuspid stenosis and atreia but is equally characteristic of of severe py hypertension and severe py stenosis it is pable and transmitted to the liver and tends to be increased by inspiration here is a case of mitost stenosis with severe reactive palmary hypertension due to a high palmary vascular resistance the giant a is well seen in the right internal jugular pulse and measures about 6 cm above the sternal angle on inspiration its amplitude increases even though the mean right atrial pressure may fall and here is a man with severe per valve stenosis with normal aortic root it has a conspicuous a wave the sinosis is due to reversed into atrial shunt also the slight claing of the fingers you see the Venus pulse is moving the lobe of the air that the large Venus wave is presystolic can be seen by timing it against the temporal arterial pulse which may be observed just in front of the ear it is shown very clearly there from this angle the height of the a-wave may be compared with the height of V which can also be seen just there in the super cicular fusser you can see V just coming up the giant airwave also occurs in tricuspid treia particularly when associated with a ferino rather than a large atrial SLE effect such was the case in this cyos go the degree of clubbing emphasizes the low level of the arterial oxygen saturation the giant airwave is well seen timed against the cored pulse it is obviously presystolic the time relationship between the Venus and arterial pulses may be analyzed by inspection in this closer view you can see the arterial pulse in that shadow there just below the lobe of the ear the powerful right atrial contraction responsible for the giant a-wave is due to increased resistance to right ventricular filling acting over a long period of time it serves to increase the contractile force of the right ventricle in accordance with starling's law which states that within certain limits the force of cardiac contraction varies directly with the length of the muscle fibers at the end of diasty the giant a wave rarely occurs in poundy hypertension when there is free communication between the ventricles as in fisted try on the left there and eangus complex on the right here is the child with fogy and you see very little in the neck just a very small a-wave here is the patient with Eisen Mangus complex and in these circumstances the right ventricular systolic pressure never rises above systemic level and the right ventricle is able to adapt itself to this ceiling with Little Help from its atrium h