Avaliação funcional do endotelio venoso e arterial em pacientes com hipertensão arterial refrataria / Functional evaluation of venous and arterial endothelium in patients with refractory hypertension

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Refractory Hypertension (RH) is conventionally defined as a persistent elevation in blood pressure (systolic >140 or diastolic >90 mmHg), even on a triple drug regimen at maximal doses including a diuretic, in patients with good adhesion and without secondary causes of hypertension or pseudo-hypertension. When exposed to risk factors, such as hypertension, the endothelium presents functional alterations, denominated endothelial dysfunction, with a reduced bioavailability of nitric oxide (NO) and vasodilation agents or an increased production of vasoconstrictor agents. The objective of this work was to evaluate the vascular endothelial function in venous and arterial networks of patients with RH After careful selection, a total of 86 patients were included in the study; 33 were characterized as resistant hypertensives (50.7±8.5 years), 28 as controlled hypertensives (54.9±12.0 years) and 25 as apparently healthy volunteers (35.8±12.1 years). All participants were submitted to an evaluation of the venous endothelial function by the dorsal hand vein technique, the arterial endothelium by flow-mediated vasodilation and the Arterial Stiffness. The main results of this study showed: a) a significant difference between the RH and NT Groups (p<0.05) in respect to endothelial-dependent vasodilatation in the venous network; this was not seen in endothelium-independent vasodilatation induced by sodium nitroprusside; and b) functional alterations of the arterial network as seen by endothelial-dependent vasodilation comparing the RH and NT (p<0.0005) and CH and NT (p<0.003) and endothelial independent vasodilatation on evaluating the pharmacological response comparing RH and NT (p<0.0001) and CH and NT (p<0.01); and c) arterial stiffness by pulse wave velocity comparing the RH and NT Groups (p<0.0001) and CH and NT (p<0.03). RH patients present with venous vascular dysfunction, identified by a decrease in the endothelium-dependent vasodilatation characterized by a reduction in compliance of the dorsal hand vein in response to the administration of acetylcholine. Additionally, a decrease in nitroglycerin-induced flow-mediated vasodilatation (brachial artery) was observed and elevated arterial stiffness

ASSUNTO(S)

hipertensão oxido nitrico hypertension compliance nitric oxide complacencia (medida de distensibilidade) endotelio endothelium

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