Is the Munich Valsalva Implantation Technique (MuVIT) the One-Size-Fits-All Maneuver for Cardiac Output Reduction During TEVAR?

2021 ◽  
pp. 152660282198934
Author(s):  
Fabrizio Monaco ◽  
Gaia Barucco ◽  
Luca Bertoglio
Keyword(s):  
Cardiac Output ◽  
Implantation Technique ◽  
The One

Pushmi-Pullyu and the Right Atrium

2011 ◽  
pp. 55-62
Author(s):  
James R. Munis
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Right Ventricle ◽  
Flow Rate ◽  
Blood Flow Rate ◽  
The Other ◽  
Right Atrial ◽  
The One ◽  
The Right ◽  
Point Of Intersection

What does right atrial pressure (PRA) do to cardiac output (CO)? On the one hand, we've been taught that PRA represents preload for the right ventricle. That is, the higher the PRA, the greater the right ventricular output (and, therefore, CO). This is simply an application of Starling's law to the right side of the heart. On the other hand, we've been taught that PRA represents the downstream impedance to venous return (VR) from the periphery. That is, the higher the PRA, the lower the VR, and therefore, the lower the CO. The point of intersection between the 2 curves defines a unique blood flow rate, which is both CO and VR at the same time.

The Munich Valsalva Implantation Technique (MuVIT) for Cardiac Output Reduction During TEVAR: Vena Cava Occlusion With the Valsalva Maneuver

2020 ◽  
pp. 152660282096137
Author(s):  
Nikolaos Tsilimparis ◽  
Jan-Michel Abicht ◽  
Jan Stana ◽  
Nikolaos Konstantinou ◽  
Barbara Rantner ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Aortic Arch ◽  
Valsalva Maneuver ◽  
Pulmonary Veins ◽  
Vena Cava ◽  
Intrathoracic Pressure ◽  
Implantation Technique ◽  
Stent Grafts ◽  
Noninvasive Technique ◽  
Invasive Techniques

Purpose To demonstrate a physiologically induced alternative to the typical methods of reducing cardiac output during deployment of stent-grafts in the aortic arch and proximal aorta. Technique A modified Valsalva maneuver, the Munich Valsalva implantation technique (MuVIT), to raise the intrathoracic pressure, minimize backflow, and reduce the cardiac output is illustrated in a patient undergoing a triple-branch thoracic endovascular aortic repair (TEVAR). During manual mechanical ventilation, the adjustable pressure-limiting valve is carefully closed to 25 mm Hg, creating “manual bloating” of the lungs and sustained apnea. The increased intrathoracic pressure causes compression of the vena cava and pulmonary veins, reducing the venous backflow and gradually decreasing the arterial pressure. Once the desired pressure is obtained, the stent-graft is accurately deployed. The airway pressure is thereupon slowly reduced, and the patient is taken back to normal ventilation. The procedure is then finished following standard practice. Conclusion The MuVIT is a simple, noninvasive technique for cardiac output reduction during aortic arch TEVAR, eliminating the need for other invasive techniques.

scholarly journals The features of hemodynamic support of exercise stress in patients with neurocirculatory dystonia

2018 ◽  
Vol 9 (1) ◽  
pp. 49-53
Author(s):  
Dmitriy D. Zotov ◽  
Vladimir A. Isakov
Keyword(s):  
Physical Activity ◽  
Cardiac Output ◽  
Vascular Tone ◽  
Venous Return ◽  
Recovery Period ◽  
Young Patients ◽  
Exercise Stress ◽  
Relative Reduction ◽  
Hemodynamic Support ◽  
The One

Neurocirculatory dystonia occupies a special place among the most common cardiovascular diseases. On the one hand, it is almost the most often diagnosed cardiologic ambulatory disease in young patients, on the other hand, its clinical-nosological framework and diagnostic criteria have remain not completely defined just as decades ago. One of the characteristic manifestations of neurocirculatory dystonia is a reduction in physical capacity of patients, due both to the lack of strong-willed qualities and detraining, and disorders of oxygen and hemodynamic support of physical activity. In this study, it was shown that one of the factors limiting exercise tolerance in patients with neurocirculatory dystonia, is the lack of growth of parameters of cardiac output at all levels of exercise stress. These features of hemodynamic support of physical activity were most pronounced in patients with low tolerance to the load, while in the group with high physical ability they were in limits of statistically non-significant trends. The recovery period in patients neurocirculatory dystonia was extended: heart rate, in contrast to the healthy persons, did not return to initial values even for 10 minutes. Throughout the recovery period, patients remained observed at the peak of the load relative reduction in stroke and cardiac indexes. Perhaps one of the causes of hemodynamic dysadaptation in NDC patients to physical activity and reduced physical performance is a violation of their orthostatic reactions, the lack of mechanisms that ensure adequate venous return and cardiac output. Hyper-reactivity of the cardiovascular system, manifested in a consistent trend of tachycardia and increased peripheral vascular tone, may play a compensatory role.

scholarly journals Pengukuran Indeks Syok untuk Deteksi Dini Syok Hipovolemik pada Anak dengan Takikardia: telaah terhadap perubahan indeks isi sekuncup

Sari Pediatri ◽  
2016 ◽  
Vol 15 (5) ◽  
pp. 319
Author(s):  
Markus M. Danusantoso
Keyword(s):  
Cardiac Output ◽  
Cardiac Output Monitor ◽  
The One

Latar belakang. Syok merupakan gawat darurat yang sering terjadi pada anak dengan manifestasi klinis awal takikardia sebagai kompensasi atas penurunan indeks isi sekuncup (IIS). Indeks syok (rasio laju jantung terhadap tekanan darah sistolik) berhubungan erat dengan IIS pada orang dewasa dan dapat digunakan menilai beratnya syok serta keberhasilan resusitasi cairan secara sederhana dan murah. Hal ini belum pernah dicoba untuk diterapkan pada anak.Tujuan. Menilai kemampuan indeks syok sebagai deteksi dini syok hipovolemik pada anak dengan takikardia.Metode. Uji diagnostik dan studi kuasi eksperimental (the one group pretest-posttest design) pada anak dengan takikardia yang dilakukan resusitasi cairan. Indeks isi sekuncup diukur dengan alat USCOM (ultrasound cardiac output monitor). Indeks syok dan IIS diukur sebelum dan setelah resusitasi cairan. Peningkatan IIS ≥10% setelah resusitasi cairan merupakan baku emas keberhasilan resusitasi cairan.Hasil. Duapuluh delapan (70%) di antara 40 subjek penelitian memiliki IIS rendah dan indeks syok sebelum resusitasi cairan berkisar antara 1,12-2,04. Duabelas (30%) subjek dengan IIS normal dan indeks syok sebelum resusitasi cairan berkisar antara 1,00-1,74. Tidak terbukti terdapat korelasi antara indeks syok dengan IIS sebelum (p= 0,845; r 0,32) dan setelah resusitasi cairan (p= 0,112; r 0,256). Penurunan indeks syok optimal setelah resusitasi cairan adalah ≥0,02 (IK 95% 0,504 sampai 0,835) dengan sensitivitas 60,71% dan spesifisitas 66,67%.Kesimpulan. Pengukuran indeks syok tidak terbukti dapat digunakan untuk deteksi dini syok hipovolemik pada anak dengan takikardia. 

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Fundamental Research into Thin Films in a Developing Country

1972 ◽  
Vol 30 ◽  
pp. 500-501
Author(s):  
J.A. Eades ◽  
E. Grünbaum
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Empirical Process ◽  
Nucleation And Growth ◽  
Research Groups ◽  
Film Research ◽  
Fundamental Research ◽  
Controlled Deposition ◽  
The One ◽  
The University

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

Preparation of Electron Transparent Metal-Matrix Composites

1968 ◽  
Vol 26 ◽  
pp. 334-335 ◽  
Author(s):  
M. R. Pinnel ◽  
A. Lawley
Keyword(s):  
Stainless Steel ◽  
Load Transfer ◽  
Volume Fraction ◽  
Steel Wire ◽  
Initial Step ◽  
Interfacial Region ◽  
Matrix Composites ◽  
Specific Test ◽  
The Matrix ◽  
The One

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.

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