大動脈中を伝播する圧波形の変化について

抄録

The transformation of pressure wave traveling along the aorta was studied in 37 patients. The pressure waves were recorded by the catheter with a micromanometer inserted percutaneously from the femoral artery up to the aortic root at intervals of 10 cm. The amplitude ratio of the pressure wave at the bifurcation of the common iliac arteries to the pressure wave at the aortic root was 1.31 ± 0.03 and decreased with age. The upstroke of the pressure wave became steeper along the aorta, particularly at the abdominal aorta. Fourier analysis of the pressure wave showed that for harmonics 1, 2, 3, 4, 5, and 6, the moduli increased with distance along the aorta and that for harmonics 5, and 6, there was the inflextion point at the distance of 20 cm from the aortic root. In the old patients ( n=7, 65.9± 1.4 years ), the moduli for each harmonic less increased than that in the young patients ( n=8, age 33.3 ± 0.6 years ) and the inflextion points were prominent in the young patients. The regional wave velocity in the descending thoracic aorta was smaller than that in the ascending aorta.
These observations give us the following suggestions : 1) in the young patients, there is one predominant reflection site in the peripheral arterial system, 2) the degree of elastic non-linearity of the vessel walls is larger at the abdominal aorta, 3) the elasticity in the ascending aorta is smaller than that in the descending thoracic aorta.