Objectives: Arterial stiffness is widely accepted as an important predictor of cardiovascular disease (CVD) development. While obesity is generally associated with increased CVD risk, there is evidence that overweight patients with existing CVD may have better clinical outcomes than their lean counterparts. Our study sought to observe any potential association between brachial−ankle pulse wave velocity (BAPWV), a marker of arterial stiffness related to CVD risk, and Body Mass Index (BMI), a crude and widely used measure of obesity.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
November 2021
Background: The use of wearable cuffless blood pressure (BP) devices is becoming commercially prevalent with little published validation information. Most devices rely, at least in part, on the relationship between pulse arrival time (PAT) and BP, a theoretical fundamental relationship that was first commercially exploited in 1993 with the release of the Casio BP-100 digital watch.
Objective: This study explored the PAT method of BP estimation in a commercial device where it first began, the Casio BP-100 (Model No.
Introduction: Ventricular function in elderly patients with aortic stenosis is impeded both by restricted aortic flow and arterial stiffening. A number of patients continue to have exertional intolerance after relief of aortic valvular obstruction due to unrecognized ventriculo-arterial coupling mismatch.
Hypothesis: Quantification of valvulo-arterial load (VAL), using a simultaneous applanation tonometry/cardiac magnetic resonance (CMR) technique, can accurately assess the relative contributions of aortic stiffness and valve gradient in older patients with aortic stenosis.
Cardiovasc Eng Technol
June 2020
Purpose: Optimal assessment of cardiovascular performance requires simultaneous measurement of load independent left ventricular (LV) contractility, arterial function and LV/arterial coupling. We aimed to demonstrate feasibility of non-invasive ventricular pressure-volume and aortic pressure-flow-impedance measurements using simultaneous arterial tonometry (AT) and cardiovascular magnetic resonance imaging (CMRI).
Methods: 21 consecutive patients referred for CMRI were enrolled to undergo a simultaneous AT and CMRI protocol.
Despite multiple studies, it has not been possible to account for the normal changes of blood pressure that occur from infancy to old age. We sought a comprehensive explanation, by linking brachial pressure with the well documented changes in the arterial pulse waveform, whose peak and nadir determine systolic, diastolic and pulse pressure in brachial arteries. Changes in humans arterial pulse wave contour from birth to old age can be readily explained on (i) growth, with increasing length of the body from birth to adolescence, and adult height maintained thereafter, and (ii) degeneration and dilation of the aorta from elastic fibre fracture throughout life, causing progressive increase in aortic pressure wave amplitude from early return of wave reflection, and summation of incident with reflected waves in systole.
View Article and Find Full Text PDFInvasive studies of the twentieth century showed the value of aortic pressure-time integrals as markers of myocardial oxygen demand and supply. More recent studies have used these concepts to evaluate the mechanisms of ischemic predisposition using noninvasive arterial tonometry in cardiology outpatients. We sought to evaluate the spectrum of myocardial oxygen demand and supply in a large cross-sectional community sample of healthy volunteers and identify the roles of age, sex, and wave reflection.
View Article and Find Full Text PDF"Structure and Function of Arteries"-is a topic of great importance to those who deal with arterial hypertension, since it links the source of flow, the left ventricle of the heart (whose output is pulsatile) to the peripheral tissues (whose flow is near continuous). The arterial tree acts passively as a conduit and cushion, and the interaction of heart, arterial tree, and organs is conventionally gauged on the basis of blood pressure measured by cuff in a conveniently located place (the brachial artery). For any precision and perspective to be gained, measurements of brachial systolic and diastolic pressure need be supplemented by other information.
View Article and Find Full Text PDF: Whether isolated systolic hypertension in the young (ISHY) implies a worse outcome and needs antihypertensive treatment is still a matter for dispute. ISHY is thought to have different mechanisms than systolic hypertension in the elderly. However, findings from previous studies have provided inconsistent results.
View Article and Find Full Text PDFBackground: Cerebral syndromes in older humans, secondary stroke in younger persons following trauma, and sickle cell anaemia in children, are linked by unexplained microvascular damage and high cerebral pressure or flow pulsations. The aim of this study was to characterize age-related pressure and flow waveforms patterns entering the brain, to explain these in terms of disturbed physiological function, and to consider clinical implications.
Method: Blood flow velocity waves were measured in four cerebral vascular territories by transcranial Doppler of 1020 apparently normal patients (497 men, 21-78 years).
This paper aims to summarize and map contemporary views on some contentious aspects of arterial hemodynamics that have remained unresolved despite years of research. These were discussed during a workshop entitled held in London on June 14 and 15, 2016. To do this we formulated a list of potential consensus statements informed by discussion at the meeting in London and quantified the degree of agreement and invited comments from the participants of the workshop.
View Article and Find Full Text PDFIn the time domain, pulsatile flow and pressure can be characterised as the ratio of the late systolic boost of flow or pressure to the pulse amplitude so as to estimate the hydraulic input to the brain. While vascular impedance has been widely used to represent the load presented to the heart by the systemic circulation, it has not been applied to the cerebral circulation.We set out to study the relationship between the pressure and the flow augmentation index (AIx) in the time domain and to determine cerebral vascular impedance using aortic blood pressure and cerebral blood flow waveforms in the frequency domain.
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