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Purpose: Helical flow has been shown to be present in the heart and arteries, but its existence in veins has not been demonstrated before. This study aimed to investigate if helical flow is present in the venous system and if the venous valves contribute to development of this flow pattern.
Methods: Color and spectral Doppler were used to calculate the true velocity vectors at five cross-sectional planes of the femoral and common femoral veins in 10 healthy individuals and eight patients with chronic venous disease.
Results: This study demonstrated that helical flow is a normal finding in the segments of veins that are in close proximity and downstream from a venous valve and a venous junction. This flow pattern is more prevalent when the calf muscle pump is active. Incompetence of the proximal great saphenous vein affects the outflow pattern, so that the helical flow is no longer present and is replaced by disorganized turbulent flow.
Conclusions: These findings suggest that helical flow is detectable, may have a physiological role in venous circulation, and the absence of it may be a feature of venous disease.
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http://dx.doi.org/10.1016/j.jvsv.2012.08.002 | DOI Listing |
J Cereb Blood Flow Metab
September 2025
iInstitut de Mécanique des Fluides de Toulouse (IMFT), Université de Toulouse, CNRS, INPT, Université Toulouse III - Paul Sabatier (UPS), Toulouse, France.
Cerebral Amyloid Angiopathy, a common age-related small vessel disease leading to hemorrhagic stroke, shares many characteristics with Alzheimer's disease: toxic amyloid deposits, microvascular alterations and enlarged perivascular spaces (EPVS). Together, PVS enlargement, reduced amyloid-β clearance and further accumulation form a vicious cycle underlying disease progression. Yet, the neuropathological correlates of EPVS, including the associated angioarchitecture, are poorly understood.
View Article and Find Full Text PDFLab Chip
September 2025
Department of Engineering Design, Indian Institute of Technology Madras, India.
Microfluidic devices offer more accurate fluid flow control and lower reagent use for uniform nanoparticle synthesis than batch synthesis. Here, we propose a microfluidic device that synthesizes uniform iron oxide nanoparticles (IONPs) for highly efficient intracellular delivery. The 3D-printed device was fabricated, comprising two inlets in the T-shaped channel with an inner diameter of 2 mm, followed by a helical mixing channel with a single outlet.
View Article and Find Full Text PDFGrowth and remodeling of the cardiac outflow tract (OFT) is poorly understood but associated with serious congenital heart defects (CHD). While only a minority of CHDs have identifiable genetic causes, the functional roles of mechanical forces in OFT remodeling are far less characterized. A key barrier has been the lack of longitudinal investigations examining the interplay between dynamic blood flow and wall motion across clinically relevant stages.
View Article and Find Full Text PDFMagn Reson Med
September 2025
Department of Integrative Bioscience and Biomedical Engineering, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan.
Purpose: This study investigated the effect of bicuspid aortic valve (BAV) morphology and ascending aortic curvature (AAAc) bending angles on aortic hemodynamics, focusing on transvalvular jets and secondary helical flows that contribute to systolic hemodynamic stress linked to aortic complications.
Methods: Using an MRI-compatible pulsatile flow and pressure system, 24 configurations involving six aortic valves (three Type 1 asymmetric BAVs, two Type 0 symmetric BAVs, and one tricuspid aortic valve [TAV]) across four ascending aortic morphologies-two diameters (30 mm and 40 mm) and two AAAc angles (130° and 109°)-were analyzed through four-dimensional-flow MRI measurements.
Results: Three Type 1 BAVs displayed highly deviated transvalvular jets directed toward the aortic wall on the side of the nonfused cusp.
Int J Biol Macromol
August 2025
Drug Discovery and Development Laboratory (DDD Lab), Department of Pharmaceutical Technology, Jadavpur University, Kolkata 700032, India. Electronic address:
GIRK channels are crucial in regulating cardiac excitability and present promising therapeutic targets. Notably, the genetic absence of GIRK4 prevents atrial fibrillation (AF) in knockout mice, yet research on specific GIRK4 modulators is limited. Addressing the challenges posed by GIRK4's intrinsic constitutive activity, we hypothesize that a GIRK inverse agonist unlike the traditional antagonist can actively downregulate the channel activity alongside reduction of the aberrant basal signaling which can translate to enhanced therapeutic efficacy.
View Article and Find Full Text PDF