Paradoxical vasodilation during lower body negative pressure in patients with vasodepressor carotid sinus syndrome

被引：8

作者：

Mangoni, AA ^{[1
]}

Ouldred, E ^{[1
]}

Allain, TJ ^{[1
]}

Close, JCT ^{[1
]}

Hilton, D ^{[1
]}

Swift, CG ^{[1
]}

Lyons, D ^{[1
]}

Jackson, SHD ^{[1
]}

机构：

[1] Univ London Kings Coll, Guys Kings & St Thomas Sch Med, Dept Hlth Care Elderly, London WC2R 2LS, England

来源：

JOURNAL OF THE AMERICAN GERIATRICS SOCIETY | 2003年 / 51卷 / 06期

关键词：

carotid sinus syndrome; vasodepressor form; adrenergic receptors; autonomic nervous system; baroreceptors;

D O I：

10.1046/j.1365-2389.2003.51269.x

中图分类号：

R592 [老年病学]; C [社会科学总论];

学科分类号：

03 ; 0303 ; 100203 ;

摘要：

OBJECTIVES: To elucidate the pathophysiological mechanism of the vasodepressor form (VD) of carotid sinus syndrome (CSS) by maneuvers designed to induce generalized sympathetic activation after baroreceptor unloading (lower body negative pressure, LBNP) or direct peripheral adrenoreceptor stimulation via local administration of norepinephrine (NA). DESIGN: Subjects were identified with VD of CSS through diagnostic testing. SETTING: Research laboratory. PARTICIPANTS: Eleven young controls (YC) (mean age +/- standard error of mean = 22.8 +/- 0.7), eight elderly controls (EC) (72.6 +/- 0.6), and eight elderly patients with VD (78.7 +/- 1.7). MEASUREMENTS: Forearm arterial blood flow (FABF) was measured in the left and right arms by venous occlusion plethysmography. Measurements were performed during baseline conditions, LBNP (-20 mmHg), and intra-arterial NA infusion in the left brachial artery at three progressively increasing rates (60, 120, and 240 pmol/min). RESULTS: During LBNP, FABF significantly decreased in YC (baseline 3.61 +/- 0.30 vs -20 mmHg 2.96 +/- 0.24 mL/100 g/min, P = .030) and EC (4.05 +/- 0.74 vs 3.69 +/- 0.65 mL/100 g/min, P = .033) but increased in elderly patients with VD (3.65 +/- 0.60 vs 4.54 +/- 0.80 mL/100 g/min, P = .020). During NA infusion, a significant forearm vasoconstriction occurred in YC (FABF left:right ratio 1.00 +/- 0.05 at baseline; 0.81 +/- 0.08 at 60 pmol/min, P = .034; 0.81 +/- 0.05 at 120 pmol/min, P < .001; 0.72 +/- 0.04 at 240 pmol/min, P < .001), whereas no significant FABF changes were observed in EC (1.04 +/- 0.06; 0.96 +/- 0.07, P = .655; 0.89 +/- 0.10, P = .401; 0.94 +/- 0.10, P = .590) or elderly patients with VD (1.04 +/- 0.06; 1.16 +/-0 .10, P = .117; 1.04 +/- 0.08, P = .602; 1.11 +/- 0.10, P = .305). CONCLUSION: VD of CSS is associated with a paradoxical vasodilatation during LBNP and an impairment of peripheral alpha-adrenergic responsiveness, which may be age-related.

引用

页码：853 / 857

页数：5

共 28 条

[1] EXCITATION OF CHOLINERGIC VASODILATOR NERVES TO HUMAN SKELETAL MUSCLES DURING EMOTIONAL STRESS [J].