PHYSIOLOGIC CONSEQUENCES OF CONGENITAL HEART DISEASE 



445 



Pressure - mm Hg 

 ISO r- 



ubclavian Artery 



5 cm Withdrawal 



Radial Artery 

 60 cm 



FIG. 15. Pulse contours in a healthy 

 30-year-old man, showing transforma- 

 tion of pressure pulse in subclavian- 

 radial system. Pressure pulses were re- 

 corded consecutively during withdrawal 

 of tip of arterial catheter from subclav- 

 ian artery near aorta to radial artery in 

 left arm. Onset of each pressure pulse 

 is aligned for purposes of comparison. 

 .\s pulse wave moves peripherally, 

 initial wave steepens and increases in 

 magnitude, dome-shaped systolic maxi- 

 mum becomes peaked, and dicrotic halt 

 moves down and to right and becomes 

 slurred. Low-amplitude, central post- 

 dicrotic wave is not seen after catheter 

 has been withdrawn 10 cm or more. 

 Prominence of radial dicrotic wave is 

 due, in part, to change in position of 

 dicrotic halt. Horizontal broken line 

 intersecting onset of each pulse contour 

 is calibration reference point (90 mm 

 Hg). Interval of time from peak of R 

 wave of electrocardiogram to onset of 

 systolic upswing of each pulse wave is 

 indicated by duration of each tracing to 

 left side of short vertical lines, which 

 mark onset of systole for each pulse. 



sites in the arterial system of a normal man demon- 

 strate that the wave form of the pulse changes remark- 

 ably as it moves to the periphery and that the con- 

 tours recorded simultaneously from different arteries 

 are quite diflferent from one another. 



The contour of the normal aortic pulse char- 

 acteristically has an anacrotic shoulder between the 

 onset and the maximum of systole, and this maximum 

 is rounded or plateau-shaped. This was first demon- 

 strated by Katz and colleagues (145). At the periph- 

 ery, however, the rise of pressure to the systolic 

 maximum is relatively more rapid, there is no 

 anacrotic pause on the ascending limb, and the 

 systolic maximum is peaked. The systolic pressure 

 increases as the pulse moves to the periphery; for 

 example, in the subject whose pulse contours are 

 shown in figure 1 4 the systolic pressure in the aorta 

 was approximately 125 mm of mercury, whereas at 

 the radial artery it was 140 mm and at the dorsalis 

 pedis artery 155 mm. The diastolic and mean arterial 

 pressures decrease slightly as the pulse travels to the 

 periphery. 



The transformation of pressure pulses recorded 

 consecutively during withdrawal of the tip of an 

 arterial catheter from the subclavian artery near the 

 aorta to the radial artery in the left arm is shown in 

 figure 15. A dicrotic halt is seen in the subclavian 



pulse contour, which is followed by a small, post- 

 dicrotic wave. As the pulse wave moves out into the 

 arm, the initial wave becomes steeper and larger in 

 magnitude, the maximal pressure becomes peaked, and 

 the dicrotic halt tends to move down and out. At the 

 radial artery the wave that occurs between the 

 systolic maximum and the dicrotic halt appears to be 

 a remnant of the plateau-like maximum of the sub- 

 clavian contour. The small aortic postdicrotic wave 

 disappears shortly after the pulse wave enters the 

 subclavian radial system (285). 



In aortic stenosis the aortic pressure rises steeply 

 at first but is soon interrupted by the anacrotic 

 incisura, following which the pressure rises more 

 slowly until the very end of systole (fig. 16). The 

 initial steep rise becomes progressively shorter and the 

 anacrotic shoulder occupies lower and lower levels as 

 the degree of stenosis is increased. No postdicrotic 

 wa\e is identifiable on the aortic contour. Wright & 

 Wood (285) oi3ser\ed that the central postdicrotic 

 wave usually is absent in patients who have significant 

 aortic stenosis. 



The aortic diastolic presstire is slightly greater than 

 the radial diastolic pressure, as in normal persons. 

 Unlike the normal state, however, the two contours 

 are similar (fig. 16). An aisnormal anacrotic pause is 

 seen on the radial contour, the increase to the svstolic 



