YF Cheung

Abstract

Arterial stiffness, the rigidity of the arterial wall, owes its significance to a direct relationship with impedance of the arterial system, and hence the left ventricular afterload. In adults, arterial stiffness has been considered as a marker of vascular disease and is emerging as an independent cardiovascular risk factor. There is accumulating evidence that this may also be true in children. Several paediatric clinical entities may affect normal functioning of the arterial system and may have an impact on long term cardiovascular health. Both prenatal and postnatal influences affect the age-dependent evolution of arterial stiffness. The prenatal influence of reduced fetal growth is illustrated by the findings of increased arterial stiffness in individuals born small and the growth-restricted donor twins in twin-twin transfusion syndrome. Postnatal structural alteration of arteries secondary to childhood vasculitides increases peripheral conduit arterial stiffness significantly. Furthermore, the magnitude of vascular inflammation during the acute phase may have important bearings on late arterial stiffening. Functional alterations of the arteries may also increase arterial stiffness. Endothelial dysfunction, documented in children with familial hypercholesterolaemia, obesity and beta-thalassaemia major, has a direct relationship with arterial stiffening. Alternatively, enhanced sympathetic tone, as might occur in childhood sleep-related disorders, may increase arterial stiffness. With the availability of noninvasive techniques for the determination of arterial stiffness in children, longitudinal studies incorporating this measurement may unveil its prognostic value in the paediatric at-risk population.

動脈的硬度，即動脈壁的硬度，歸終予臨床意義在於與動脈系統阻力直接相關，因而與左心室後負荷直接相關。在成人，動脈硬度己被認為是一個心血管疾病的標記物，且正在顯現為一個獨立的心血管危險因素。不斷增多的證據表明在兒童也是的確存在的，目前發現幾種兒科臨床情況可以影響動脈系統的正常功能，而且長期作用可影響心血管的健康。在產前和產後兒童影響動脈硬度的進展依賴於年齡增長，如在雙胎輸血綜合征中骨骼小和生長受限制供體，在產前胎兒生長障礙被發現有動脈硬度的增加的表現；產後繼發於兒童血管病的動脈結構改變使外周動脈硬度明顯增加，進一步發現，在血管炎急性階段的炎症強度可能在以後動脈硬度增加起重要作用。動脈功能的改變也可以增加動脈的硬度。內皮的功能不良，伴有家族性高膽固醇血症兒童，肥胖和 β－地中海貧血年長後，均與動脈硬度增加有直接關係。另一方面，交感神經張力增加，如發生在睡眠障礙疾病的兒童，可以增加動脈的硬度。隨著無創技術測量動脈硬度在兒童中的應用，這種測量納入群體研究後將揭示在兒科高危人群中的預後價值。