当前位置： SCI文献检索 > JOURNAL OF HYPERTENSION期刊下所有文献 > Effect of postural changes on cardiovascular responses to static exercise in hypertensive human beings.

Effect of postural changes on cardiovascular responses to static exercise in hypertensive human beings.

Abstract：

OBJECTIVE:In hypertensive patients, exaggerated increases in vascular resistance and arterial blood pressure have been reported on changing posture from supine to upright. In this study we tested the hypothesis that in hypertensive subjects, upright posture induces an increase in the vasoconstrictor and pressor responses to physical exercise. SUBJECTS AND METHODS:We studied 17 males with mild hypertension and 10 sex- and age-matched normotensives. Each performed three bouts of static handgrip at 30% maximum voluntary contraction for 2 min after 10 min of supine rest and, in sequence, after 10 min of sitting and 10 min of standing. Arterial pressure, heart rate and forearm vascular resistance were measured by Finapres and plethysmography, respectively. RESULTS:Exercise posture did not affect the mean arterial pressure and heart rate responses to static handgrip. No significant differences in these responses were observed between the hypertensives and the normotensives in any posture. In the hypertensives (n = 12), forearm vascular resistance did not change significantly from resting values during supine and sitting static handgrip but increased significantly during standing static handgrip. In the normotensives, forearm vascular resistance did not change significantly from resting values during static handgrip in any posture. The forearm vascular resistance response to the standing static handgrip was significantly greater in the hypertensives than the normotensives. The algebraic sum of forearm vascular resistance responses to postural change from sitting to standing plus that induced by sitting static handgrip (i.e. additive reflexes) was significantly less than the forearm vascular resistance response to the standing static handgrip (i.e. combined relexes), indicating a facilitatory interaction between exercise and orthostatic stimuli in hypertensives. In contrast, the algebraic sum of the heart rate responses to postural change from sitting to standing plus that induced by sitting static handgrip was significantly greater than the response to standing static handgrip, indicating an inhibitory interaction. CONCLUSIONS:In hypertensive patients, physiological orthostasis causes an increased vasoconstrictor response to static exercise, but this is opposed by an inhibitory influence on the heart rate response, with the result that the pressor response to static exercise is unaffected by upright posture.

journal_name

J Hypertens

journal_title

Journal of hypertension

authors

Legramante JM,Massaro M,Raimondi G,Castrucci F,Cassarino S,Peruzzi G,Iellamo F

doi

10.1097/00004872-199917010-00015

subject

Has Abstract

pub_date

1999-01-01 00:00:00

pages

99-105

issue

eissn

0263-6352

issn

1473-5598

journal_volume

pub_type

杂志文章

在线工具

Effect of postural changes on cardiovascular responses to static exercise in hypertensive human beings.