A study was performed to determine if there are differences in the effect of placebo, lisinopril or amlodipine on carotid artery blood flow in patients with hypertension. Twelve (12) hypertensive patients were treated with placebo, lisinopril or amlodpine for 7 days each in a double blind, randomized, cross over experimental design (each patient received each drug for 7 days, followed by 7 days with no drug with the order of drug administration randomized). Carotid artery blood flow velocity was measured using Doppler Ultrasound imaging at the end of each treatment period. Resultant data are shown below (values are blood flow velocities in cm/s): Subject Placebo Lisinopril Amlodipine Row Sum y (Row Sum y)^2/n 1 31 49 33 113 4263 2 37 45 36 118 4672 3 34 51 34 119 4686 4 29 39 31 99 3269 5 37 45 27 109 3954 6 32 52 38 121 4897 7 36 47 26 109 3937 8 48 55 33 136 6165 9 34 40 36 110 4033 10 38 43 33 114 4332 11 34 41 35 110 4033 12 38 45 34 114 4332 Totals 1376 52894 n 12 12 12 36 Mean 35.67 46.00 33.00 Variance 23.15 24.91