tokens: Arterial compliance measurements using intraarterial pulse contour analysis and a modified Windkessel model were carried out in 19 patients with isolated systolic hypertension ( > or = 160 / < or = 90 mm Hg ) and compared to measurements in 29 patients with essential hypertension ( diastolic blood pressure [ BP ] > or = 95 mm Hg ) and 47 normotensive control subjects .