抄録
In the field of experimental arteriosclerosis, it is a most important problem, how to examine the sclerotic grade of arteries non-invasively, because we desire to know the changing phases of arteriosclerosis induced in animals, and to estimate the regression or the effect of antisclerotic medicine. We already reported invasive aortic Pulse Wave Velosity (PWV) method and showed to be able to estimate the sclerotic grade of aorta by this technic. Now we improved it in some respects to establish non-invasive measurement. (Materials) Materials consisted of 32 rabbits from 28 W-280W. (Method) 1. Procedure of carotid arterial loop. We can not recongnize the pulsation of carotid artery through the skin in rabbit. So we gave two incision on the skin of the frontal neck. Then we exposed carotid artery and made it free from the surrounding tissues. It was coated by the skin to make loop, which length was about 40mm, and which diameter was about 7-10mm. 2. Measurement of blood pressure. We can estimate blood pressure from the changing phases of the waves described continuously as the diameter change of the carotid artery by the displacement transducer attached to the periphery of the cuff placed on the carotid loop. Under the cuff pressure over maximum pressure, waves will not be appeared. If a wave with a notch on the ascending limb will be appeared, it will point out maximum pressure. Next, the notch will be disappeared and wave amplitude will be reached to maximum. This point will show the minimum pressure. 3. Measurement of PWV. Pulse wave transducer were attached to carotid loop and the portion over femoral artery, and a PCG microphone to the precordium. The pulse wave velosity was then calculated from the equation PWV=D/(t+tc), where D was the distance from the upper sternal border to the point measuring femoral pulse wave. 4. normalization of PWV. PWV were dependent on minimum pressure. So we made up nomogram for normalization of PWV by invasive method in 118 rabbits. (Result) 1. Maximum and minimum pressure were estimated clearly with average error under ±2mmHg. Correlation between the first and second trial was 0.98 in maximum pressure, and 0.92 in minimum pressure. 2. In PWV, correlation between the first and the second (the next day) measurement was 0.97. Its average error was within ±0.3m/sec. 3. PWV and its standard deviation obtained were 5.5±0.49 in un der 39W group, 5.8±0.47 in 40-79W, 6.8±0.37 in 80-119W, 7.1±1.17 in 120-159W, 6.8±0.49 in over 160W. 4. PWVs were increased with ageing and its deviation became higher over 120W.
