Imanaga I, Hara H, Koyanagi S, Tanaka K
Department of Physiology, School of Medicine, Fukuoka University, Japan.
Jpn Heart J. 1998 Nov;39(6):775-84. doi: 10.1536/ihj.39.775.
The ratio of two wave components (magnitude of b/a constituting the second derivative of the plethysmogram (SDPTG) was correlated with arterial distensibility. Eighty-two subjects (33-93 years old) were classified into three groups according to the thickness of the intima-media complex of the common carotid artery measured by B-mode ultrasonography. One group was non-atherosclerotic (without pathologic thickening) (nAS) and the other two groups atherosclerotic (mild and severe thickening, or plaque formation) (AS-1 and AS-2). Distensibility (D) of the common carotid artery was calculated from arterial dimensions and blood pressure: h/p = D, where h = (Ds-Dd)/Dd; Ds, Dd and p represent the inner diameter of the carotid artery at peak systole, at end diastole and brachial pulse pressure, respectively. The plethysmogram was recorded at the cuticle of the 2nd digit of the left hand, and the SDPTG was determined with a 10 msec time constant. D showed a significant negative correlation with age in all subjects and in the three separate groups. The correlation between age and magnitude of b/a was significantly negative in all subjects. This negative correlation was not observed in the nAS group, while it was significant in both AS-1 and AS-2. The correlation between magnitude of b/a and D was significantly positive in all subjects and in each group. Significant differences were found among the three groups for magnitude of b/a and D. These results suggest that a decrease in magnitude of b/a or in D was proportional to the thickness of the intima-media complex of the carotid artery, that is, the development of atherosclerosis. These results provide direct evidence that magnitude of b/a of the SDPTG is related to the distensibility of the peripheral artery, and suggest that magnitude of b/a is a useful non-invasive index of atherosclerosis and altered arterial distensibility.
两个波分量的比值（构成体积描记图二阶导数的b/a幅度，即SDPTG）与动脉扩张性相关。82名受试者（年龄33 - 93岁）根据B型超声测量的颈总动脉内膜中层复合体厚度分为三组。一组为非动脉粥样硬化组（无病理增厚）（nAS），另外两组为动脉粥样硬化组（轻度和重度增厚或有斑块形成）（AS - 1和AS - 2）。颈总动脉的扩张性（D）根据动脉尺寸和血压计算得出：h/p = D，其中h = (Ds - Dd)/Dd；Ds、Dd和p分别代表颈动脉在收缩期峰值、舒张期末期的内径以及肱动脉脉压。体积描记图在左手食指角质层记录，SDPTG采用10毫秒的时间常数测定。在所有受试者以及三个单独分组中，D与年龄均呈显著负相关。在所有受试者中，年龄与b/a幅度之间的相关性显著为负。在nAS组未观察到这种负相关，而在AS - 1和AS - 2组中均显著。在所有受试者以及每个组中，b/a幅度与D之间的相关性均显著为正。三组在b/a幅度和D方面存在显著差异。这些结果表明，b/a幅度或D的降低与颈动脉内膜中层复合体的厚度成正比，即与动脉粥样硬化的发展相关。这些结果提供了直接证据，表明SDPTG的b/a幅度与外周动脉的扩张性相关，并提示b/a幅度是动脉粥样硬化和动脉扩张性改变的一个有用的非侵入性指标。
