A noninvasive technique has been developed and validated for calculating capacitive and oscillatory systemic arterial compliance with the use of pulse wave analysis and a modified Windkessel model. Application of the technique to subjects with hypertension, postmenopausal women with symptomatic coronary artery disease, and appropriate control subjects has confirmed a reduction of oscillatory compliance in the disease states and an increase in capacitive and oscillatory compliances in response to vasodilator drugs. This method should be useful in screening subjects for early evidence of vascular disease and in monitoring the response to therapy.

Abstract-The objective of this study was to evaluate age-related changes in pulsatile arterial function. Aging alters arterial pulsatile function and produces consistent changes in the pressure pulse contour. A reduced systemic arterial compliance that can be derived from analysis of the pulse contour is regarded as the best clinical index of impaired pulsatile arterial function and may mark the presence of early vascular damage. We analyzed intra-arterial brachial artery waveforms in 115 healthy normotensive volunteers (83 men, 32 women) and radial artery waveforms obtained with the use of a calibrated tonometer device in 212 healthy volunteers (147 women, 65 men). A computer-based assessment of the diastolic pressure decay and a modified Windkessel model of the circulation were used to quantify changes in arterial waveform morphology in terms of large artery or capacitive compliance, oscillatory or reflective compliance in the small arteries, inertance, and systemic vascular resistance. Large artery compliance and oscillatory compliance correlated negatively with age for both invasive and noninvasive groups (rϭϪ0. 50 and rϭϪ0.55; rϭϪ0.37 and rϭϪ0.66; PϽ0.001 for all). The slopes of the regression lines for the decline in oscillatory compliance with age were significantly steeper than those recorded for large artery compliance estimates. The change in blood pressure with age independently contributed to the decrease in large artery compliance but not oscillatory compliance in both groups. Consistent age-related changes were found in the pressure pulse contour by analysis of waveforms obtained invasively or noninvasively from the upper limb. The change in the oscillatory or reflective compliance estimate was independent of blood pressure change and may represent a better marker than large artery or capacitive compliance of the degenerative aging process in altering pulsatile arterial function. (Hypertension. 1999;33:1392-1398.)Key Words: age Ⅲ compliance Ⅲ resistance Ⅲ impedance A daptations in the arterial vasculature play a critical role in influencing cardiovascular hemodynamics with advancing age. 1 The generalized structural and functional changes in the arterial circulation contribute to alterations in regional blood flow, progression of atherogenesis, and the microvascular abnormalities that occur during senescence. 2 In large arteries, aging results in progressive deposition of calcium salts, fraying and fragmentation of elastin, and an increase in the number and cross-linking of collagen fibers that alter the compliance characteristics of the vessel wall. 3 A rigid aorta is less able to buffer the pulsatile output from the heart; it contributes to an increase in systolic blood pressure and left ventricular afterload and a decrease in diastolic blood pressure and impaired coronary perfusion. Recent evidence suggests that an increase in pulse pressure is accompanied by progressive vessel wall damage and atherogenesis and is associated with an increase in cardiac morbidity and mortality rates. 4,5 In addi...

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Patient outcomes and cost were compared when home healthcare was delivered by telemedicine or by traditional means for patients receiving skilled nursing care at home. A randomized controlled trial was established using three groups. The first group, control group C, received traditional skilled nursing care at home. The second group, video intervention group V, received traditional skilled nursing care at home and virtual visits using videoconferencing technology. The third group, monitoring intervention group M, received traditional skilled nursing care at home, virtual visits using videoconferencing technology, and physiologic monitoring for their underlying chronic condition. Discharge to a higher level of care (hospital, nursing home) within 6 months of study participation was 42% for C subjects, 21% for V subjects, and 15% for M subjects. There was no difference in mortality between the groups. Morbidity, as evaluated by changes in the knowledge, behavior and status scales of the Omaha Assessment Tool, showed no differences between groups except for increased scores for activities of daily living at study discharge in the V and M groups. The average visit costs were $48.27 for face-to-face home visits, $22.11 for average virtual visits (video group), and $32.06 and $38.62 for average monitoring group visits for congestive heart failure and chronic obstructive pulmonary disease subjects, respectively. This study has demonstrated that virtual visits between a skilled home healthcare nurse and chronically ill patients at home can improve patient outcome at lower cost than traditional skilled face-to-face home healthcare visits.

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