Browsing by Subject "Blood Pressure Determination"
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Item Blood pressure management in hemodialysis patients(2016-06-03) Van Buren, PeterItem Central Hemodynamic Monitoring of Train Drivers in Western Russia(2020-01-21) Duncan, Steven G.; Chang, Mary P.; Orlov, Sergei A.; Gorenkov, Roman V.BACKGROUND: Train drivers are exposed to work-related stressors which contribute to higher rates of cardiovascular disease. No studies have characterized precursors of this effect in Western Russia. AIM: This project aims to identify early disturbances and trends in central hemodynamic parameters among young locomotive driver assistants in order to elucidate patterns of decompensation. METHODS: This study is a retrospective review of hemodynamic parameters among train conductors in the Moscow region of the Russian Federation from December 2003 to September 2004. Subjects underwent regular hemodynamic monitoring within this period before every train departure. Automated oscillometric methods were used to obtain resting measurements of blood pressure, cardiac output, pulse wave velocity, and systemic vascular resistance with the device "KAP CG osm – 'Globus'". Men with pre-existing hypertension were excluded. RESULTS: The sample was comprised of 168 individuals and 8674 unique measurements; the mean age was 26.2 ± 4.6 years with an average of 52 ± 17 measurements per person over 33.8 ± 8.9 weeks. The average values for each hemodynamic parameter were within normal limits. Across all measurements, heart rate showed the greatest time-independent variation while systolic blood pressure showed the least; coefficients of variation (σ/x̄) were 10.6% and 6.8% respectively. Hypertensive episodes were observed in 36.3% of participants. Strong, positive correlations were observed between diastolic blood pressure and systemic vascular resistance (r = 0.72, p < 0.001), systolic blood pressure and cardiac output (r = 0.71, p < 0.001) respectively. Older subjects tended to have higher diastolic blood pressure (r = 0.51, p < 0.001). Over time, systemic vascular resistance showed the greatest variance with an average upward trend when data were fit to a linear regression model. Increasing systemic vascular resistance over time was positively correlated with decreasing systolic blood pressure and increasing diastolic blood pressure. DISCUSSION: Persistent changes in central hemodynamics can precede the development of clinical arterial hypertension. The results of this study suggest that implementation of early monitoring and prophylactic measures may be beneficial for high-risk individuals.Item A Multi-Parametric Investigation of Vascular Alterations in Elderly with Hypertension(2015-01-26) Sheffield, Adam; Sheng, Min; King, Kevin; Ravi, Harshan; Peng, Shin-lei; Liu, Peiying; German, Zohre; Lu, HanzhangBACKGROUND: Along with aging comes many cardiovascular and cerebral changes that impact a person's health. These changes manifest as variances in blood pressure, brain volume, cerebral blood flow (CBF), oxygen metabolism, and neurological functioning. OBJECTIVE: The purpose of this study is to provide evidence to support new or previously known biomarkers for declining cerebrovascular health, such as cerebral arterial stiffness, reduced vessel capacity, and thickening of the extracellular matrix. METHODS: 45 participants ranging from the ages of 61 to 79 with a mean of 67 were studied using a 3 Tesla MRI. Several MRI techniques were employed to acquire and analyze data. Phase-contrast (PC) MRI was used for acquiring images of moving fluid, so that arteries containing blood flow to the brain could be isolated in order to calculate total CBF. Blood-oxygen-level dependent contrast images and end-tidal CO2 and O2 measurements were also obtained using MRI after the participants were given a different sequence of gases to breathe containing varying amounts of oxygen, carbon dioxide, and nitrogen. This allowed the cerebrovascular reactivity (CVR) and venous cerebral volume (vCBV) of the vessels to be determined. Venous oxygenation (Yv) was assessed using T2-relaxation-under-spin-tagging (TRUST) MRI technique. Linear regressions were performed to account for age, sex, and blood pressure. Data were also analyzed by putting participants with a systolic blood pressure greater than 140 into a hypertensive category for comparison. Other data acquired during or immediately prior to the MRI scans include systolic and diastolic blood pressure, brain volume, and the oxygen saturation level of venous and arterial blood. RESULTS: A p-value of <0.05 was used to determine significance. The CVR for the hypertensive group was lower than that of the non-hypertensive group (p<0.01) and CVR decreased as systolic blood pressure increased (p=0.02). CVR also decreased with increasing age (p=0.02) and was higher in males than in females (p<0.01). CBF increased with systolic blood pressure (p=0.03) and was higher in females (p=0.03). Yv also increased with systolic blood pressure (p=0.02) and correlated strongly with CBF values (p<0.001). CONCLUSION: These results support certain relationships between blood pressure and the vascular markers within the brain, which may appear before cognitive decline or clinical symptoms emerge. This study is an early step on the path to discovering easily identifiable precursors to neurological changes that take place as normal aging processes occur.Item Out-of-office BP monitoring in hypertension: where we are and where we are going(2021-09-10) Vongpatanasin, Wanpen