Effects of hydralazine versus propranolol on blood velocity patterns in patients with carotid stenosis.

1. Since endothelial damage due to flow disturbances is of postulated significance in the pathogenesis of atherosclerosis, this study examined the effects of antihypertensive drugs on carotid flow patterns in patients with known carotid stenosis. A Doppler Echoflow unit was used to display arterial velocities in red (normal range), yellow (increased velocity) and blue (abnormally increased velocity thought to represent turbulence and other departures from laminar flow). 2. Twenty patients were studied before drug, then during intravenous administration of hydralazine, 6-12 mg, and propranolol, 2-5 mg, over 10-15 min each, with return to baseline between drugs. 3. After hydralazine, the occurrence of abnormal high velocity flow patterns increased in 17 of 20 patients; there was no change in three patients. Propranolol reduced the occurrence of abnormal high velocity flow patterns in 19 of 20 patients (P less than 0.00001; chi-square). 4. These effects of antihypertensive drugs on arterial velocity patterns may be important in the selection of antihypertensive drugs to prevent or minimize the progression of atherosclerosis.