Publications by authors named "O Wieben"
Cerebral blood flow at rest declines with age. However, age-related changes in functional measures of cerebrovascular health including cerebrovascular reactivity and neurovascular coupling are not well understood. Additionally, the effect of apolipoprotein E (APOE) ε4, a strong genetic risk factor for Alzheimer's disease, on cerebral blood flow and cerebrovascular function remains unclear.
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- Right ventricular (RV) pressure-volume loops need calibration after acquisition using methods like cardiac MRI (CMR) or hypertonic saline (HS) to assess heart function accurately.
- A study involving 19 participants found that HS calibration consistently overestimated RV volumes at rest compared to CMR, leading to an underestimation of RV ejection fraction (RVEF) by approximately 8%.
- Despite discrepancies in RVEF, both calibration methods produced similar results for ventricular contractility (Ees), arterial afterload (Ea), and their relationship (Ees/Ea) during rest and exercise.
Background: Patients with syndromic heritable thoracic aortic diseases (sHTAD) who underwent prophylactic aortic root replacement are at high risk of distal aortic events, but the underlying mechanisms remain unclear. This prospective, longitudinal study evaluates the impact of valve-sparing aortic root replacement (VSARR) on aortic fluid dynamics and biomechanics in these patients.
Methods: Sixteen patients with Marfan or Loeys-Dietz syndrome underwent two time-resolved three-dimensional phase-contrast cardiovascular magnetic resonance (4D flow CMR) studies before (sHTAD-preSx) and after VSARR (sHTAD-postSx).
Sex differences in gray matter, white matter, and regional brain perfusion in young, healthy adults.
Am J Physiol Heart Circ Physiol
October 2024
Cerebrovascular and neurological diseases exhibit sex-specific patterns in prevalence, severity, and regional specificity, some of which are associated with altered cerebral blood flow (CBF). Females often exhibit higher resting CBF, but understanding the impact of sex per se on CBF is hampered by study variability in age, comorbidities, medications, and control for menstrual cycle or hormone therapies. A majority of studies report whole brain CBF without differentiating between gray and white matter or without assessing regional CBF.
View Article and Find Full Text PDFPurpose: Tricuspid valve flow velocities are challenging to measure with cardiovascular MR, as the rapidly moving valvular plane prohibits direct flow evaluation, but they are vitally important to diastolic function evaluation. We developed an automated valve-tracking 2D method for measuring flow through the dynamic tricuspid valve.
Methods: Nine healthy subjects and 2 patients were imaged.