Phasic aortic flow velocity was recorded in two patients with pulsus alternans using a flow velocity probe connected to a Doppler ultrasonic flowmeter system. The variations in beat-to-beat peak velocity paralleled the variations in arterial and ventricular systolic pressures. This study provides direct evidence that stroke volume varies during this abnormal haemodynamic status. It is conceivable, though not proved in this study, that this phenomenon may be secondary to alternation between large and small end-diastolic fibre length.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC487394 | PMC |
| http://dx.doi.org/10.1136/hrt.32.5.696 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Parametric Search for Optimal Channel Shape for Swirling Blood Flow in the Heart and Main Vessels.
Dokl Biochem Biophys
January 2025
Bakulev National Medical Research Center for Cardiovascular Surgery, Moscow, Russia.
The study presents a numerical parametric investigation of flow structures in channels with a longitudinal-radial profile zR = Const and a spherical dome at the base. The goal of the study was to examine the flow structures in these channels depending on the exponent N of the profile and the height of the dome, to determine the conditions that provide optimal centripetal swirling flow, analogous to blood flow in the heart chambers and major vessels. The investigation was conducted using a comparative analysis of flow structures in channel configurations zR = Const, carried out in two stages.
View Article and Find Full Text PDFKey Structural Features of Microvascular Networks Leading to the Formation of Multiple Equilibria.
Bull Math Biol
January 2025
Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Woodstock Rd, Oxford, Oxfordshire, OX2 6GG, UK.
We analyse mathematical models of blood flow in two simple vascular networks in order to identify structural features that lead to the formation of multiple equilibria. Our models are based on existing rules for blood rheology and haematocrit splitting. By performing bifurcation analysis on these simple network flow models, we identify a link between the changing flow direction in key vessels and the existence of multiple equilibria.
View Article and Find Full Text PDFAssociation between the Tpeak-Tend interval on admission and coronary microvascular dysfunction in Takotsubo syndrome.
ESC Heart Fail
January 2025
Division of Cardiology, Department of Medicine, Kindai University Faculty of Medicine, Osaka, Japan.
Aims: The Tpeak-Tend interval on electrocardiogram may be a predictor of worse outcomes in Takotsubo syndrome (TTS), but the mechanisms have not been fully determined. This study aimed to investigate the relationships between the corrected Tpeak-Tend (cTp-e) interval and coronary microvascular-dysfunction (CMD) assessed by the angiography-derived index of microvascular resistance (Angio-IMR) and the in-hospital prognosis in patients with TTS.
Methods And Results: We retrospectively evaluated 111 consecutive patients admitted for TTS who underwent coronary angiography at Kindai University Hospital from October 2009 to July 2023.
Accelerating computational fluid dynamics simulation of post-combustion carbon capture modeling with MeshGraphNets.
Front Artif Intell
January 2025
Lawrence Livermore National Laboratory, Livermore, CA, United States.
Packed columns are commonly used in post-combustion processes to capture CO emissions by providing enhanced contact area between a CO-laden gas and CO-absorbing solvent. To study and optimize solvent-based post-combustion carbon capture systems (CCSs), computational fluid dynamics (CFD) can be used to model the liquid-gas countercurrent flow hydrodynamics in these columns and derive key determinants of CO-capture efficiency. However, the large design space of these systems hinders the application of CFD for design optimization due to its high computational cost.
View Article and Find Full Text PDFMagnetohydrodynamic unsteady natural convection slip flow in a vertical parallel plate microchannel heated with constant heat flux.
Heliyon
January 2025
Department of Mechanical Engineering, Faculty of Engineering, Arak University, Arak 38156-88349, Iran.
This research presents a numerical study over the unsteady natural convection of an electrically conducting fluid in an open-ended vertical parallel plate microchannel under uniform and asymmetric heat flux subjected to a uniform lateral magnetic field. Slip velocity, as well as temperature jump at channel walls, are modeled using a first-order model. The effects of Knudsen number)(, heat flux ratio)rq(, Grashof number)(, and Hartmann number)M(on mass flow rate, the maximum temperature of the wall, and average Nusselt () as a function of time are discussed.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!