부산대학교 도서관

During recent decades the importance of perceiving isolated systolic hypertension (ISH) in cardiovascular pathophysiology has been changed from a benign condition to the major cardiovascular risk factor. Aging is per se associated with the deterioration in arterial compliance through both structural and functional changes in large arteries which mainly involves the intima and media. The observed changes result in a decrease of the lumen-to-wall ratio, the overall lumen cross-sectional area and an increase of arterial stiffness which especially involve the aorta and other elastic arteries. In addition to the structural changes in vessel walls, aging is associated with certain functional changes such as an increase in sympathetic system activity probably due to the age-related decreased sensitivity of beta-receptors. While the function of arterial wall alpha-receptors remains intact, in elderly subjects a shift towards arterial vasoconstriction can be observed. In many of the published studies the definition of ISH was based on the criterion 160/95 mm Hg or 160/90 mm Hg while in recognition of the high risk associated with systolic blood pressure (SBP) the WHO/ISH guidelines and Report of the Sixth Joint National Committee on Hypertension indicated that ISH should be diagnosed with SBP as ≥140 mm Hg and diastolic BP (DBP) as <90 mm Hg. Thus the setting down of normal values of SBP will lead to an earlier diagnosis and treatment of ISH. Several prospective studies, such as the US Hypertension Detection and Follow-up Programme, confirmed this and the Multiple Risk Factor Intervention Trial demonstrated that for any given level of DBP, higher SBP was associated with an increase in cardiovascular risk. Moreover, data from the Framingham Study show that ISH was associated not only with increased mortality but also cardiovascular morbidity. Risk of non-fatal stroke and myocardial infarction was increased three and two-times respectively in the presence of ISH. Three... [ABSTRACT FROM AUTHOR]