Vascular changes in different stages of hypertension. Local peripheral resistance at reactive hyperaemia.
The resting and the maximal calf blood flows at reactive hyperaemia and blood pressure were determined in a group of young persons with borderline and juvenile hypertension (stage I) and in older patients with essential (stage I and II according to WHO) and vasorenal hypertension. The findings were compared with those found in healthy controls of the same age span. The resting blood flow was the same in borderline hypertension and in HPT stage I in young persons as in the control group; in older hypertensives it was significantly lower. The maximal blood flow at reactive hyperaemia was significantly higher in the group of borderline HPT, did not differ in HPT stage I in young subjects, and was significantly lower in older subjects in all stages of HPT. A significantly higher vascular resistance was found in all groups of hypertensives except the borderline HPT both at rest and at reactive hyperaemia. The results suggest that in persons with borderline HPT only functional autoregulation takes place, whereas in HPT stage I and II and in vasorenal HPT the high vascular resistance is already an expression of structural adaption of the vascular wall in the form of its hypertrophy.
D000328:Adult; D001794:Blood Pressure; D006801:Humans; D006940:Hyperemia / Q000150:complications / Q000503:physiopathology*; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D006978:Hypertension, Renovascular / Q000503:physiopathology; D007866:Leg / Q000098:blood supply*; D008875:Middle Aged; D012039:Regional Blood Flow; D014655:Vascular Resistance