SUMMARY Noninvasive evaluation of brachial artery diameter (pulsed Doppler velocimetry) and pulse wave velocity (strain gauge mechanography) was performed in 23 normal subjects and 49 patients with uncomplicated essential hypertension. Pulsatile arterial function was described in terms of derived characteristic impedance and arterial compliance. Compared with normal controls, hypertensive patients had greater arterial diameter (p < 0.01) and pulse wave velocity (p < 0.001). Two nomograms obtained from normal subjects relating the product of age and diastolic pressure to diameter and pulse wave velocity were used for analysis of the hypertensive group; 35 patients were inside the 95% confidence limits of the diameter and pulse wave velocity nomograms (Group 1), while 14 patients were outside the pulse wave velocity nomogram (Group 2). Age and mean pressure were similar, but pulse wave velocity was higher (p < 0.001), arterial compliance lower (p < 0.001), and characteristic impedance higher (p < 0.001) in Group 2 than in Group 1. The amplitude of pulse pressure was higher in Group 2 than in Group 1 (p < 0.001), and a negative correlation was found between pulse pressure and arterial compliance in Group 2, but not in Group 1. Thus, in the majority of hypertensive patients, arterial modifications could be related to the normal influence of age and pressure. In contrast, other patients exhibited features suggesting excessive arterial stiffness, manifested by abnormally high pulse wave velocity, decreased arterial compliance, and increased characteristic impedance. (Hypertension 7: 675-680, 1985) KEY WORDS • large arteries • essential hypertension • pulsed Doppler • brachial artery diameter • pulse wave velocity • arterial compliance D AMAGE of large arteries is a major contributing factor to the high cardiovascular morbidity and mortality observed in hypertension.1 Moreover, it has been established recently that even in treated hypertensive patients, ischemic lesions continue to develop as a consequence of the injury to the large arteries. 2 Such arterial damage is nonuniform. Arteriosclerotic lesions represent the direct effect of increased intraluminal pressure on the arterial wall. However, this effect is not specific to hypertension but appears as a consequence of arterial aging caused by