380: STROKE VOLUME CHANGE PREDICTS PATIENT OUTCOME

The mitral annulus (MA) has a complex shape and motion, and its excursion has been correlated to left ventricular (LV) function. During the cardiac cycle the annulus’ excursion encompasses a volume that is part of the total LV volume change during both filling and emptying. Our objective was to evaluate the contribution of MA excursion and shape variation to total LV volume change. Nine healthy subjects aged 56 ± 11 (means ± SD) years underwent transesophageal echocardiography (TEE). The MA was outlined in all time frames, and a four-dimensional (4-D) Fourier series was fitted to the MA coordinates (3-D+time) and divided into segments. The annular excursion volume (AEV) was calculated based on the temporally integrated product of the segments’ area and their incremental excursion. The 3-D LV volumes were calculated by tracing the endocardial border in six coaxial planes. The AEV (10 ± 2 ml) represented 19 ± 3% of the total LV stroke volume (52 ± 12 ml). The AEV correlated strongly with LV stroke volume ( r = 0.73; P < 0.05). Peak MA area occurred during middiastole, and 91 ± 7% of reduction in area from peak to minimum occurred before the onset of LV systole. The excursion of the MA accounts for an important portion of the total LV filling and emptying in humans. These data suggest an atriogenic influence on MA physiology and also a sphincter-like action of the MA that may facilitate ventricular filling and aid competent valve closure. This 4-D TEE method is the first to allow noninvasive measurement of AEV and may be used to investigate the impact of physiological and pathological conditions on this important aspect of LV performance.

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Stroke volume change after digoxin loading in septic shock patients with transient left ventricular systolic dysfunction.

10.1183/13993003.congress-2018.pa2347 ◽

2018 ◽

Author(s):

Dong Hyun Lee ◽

Jin-Heon Jeong ◽

Bo Hyoung Kang ◽

Soojung Um ◽

Choonhee Son

Keyword(s):

Septic Shock ◽

Stroke Volume ◽

Volume Change ◽

Left Ventricular Systolic Dysfunction ◽

Systolic Dysfunction ◽

Left Ventricular ◽

Ventricular Systolic Dysfunction

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Carotid artery velocity time integral and corrected flow time measured by a wearable Doppler ultrasound detect stroke volume rise from simulated hemorrhage to transfusion

BMC Research Notes ◽

10.1186/s13104-021-05896-y ◽

2022 ◽

Vol 15 (1) ◽

Author(s):

Jon-Émile S. Kenny ◽

Igor Barjaktarevic ◽

David C. Mackenzie ◽

Mai Elfarnawany ◽

Zhen Yang ◽

...

Keyword(s):

Carotid Artery ◽

Stroke Volume ◽

Doppler Ultrasound ◽

Volume Change ◽

Maximum Velocity ◽

Human Model ◽

Velocity Time Integral ◽

Time Integral ◽

Simulated Hemorrhage ◽

Corrected Flow Time

Abstract Objective Doppler ultrasonography of the common carotid artery is used to infer stroke volume change and a wearable Doppler ultrasound has been designed to improve this workflow. Previously, in a human model of hemorrhage and resuscitation comprising approximately 50,000 cardiac cycles, we found a strong, linear correlation between changing stroke volume, and measures from the carotid Doppler signal, however, optimal Doppler thresholds for detecting a 10% stroke volume change were not reported. In this Research Note, we present these thresholds, their sensitivities, specificities and areas under their receiver operator curves (AUROC). Results Augmentation of carotid artery maximum velocity time integral and corrected flowtime by 18% and 4%, respectively, accurately captured 10% stroke volume rise. The sensitivity and specificity for these thresholds were identical at 89% and 100%. These data are similar to previous investigations in healthy volunteers monitored by the wearable ultrasound.

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Artifacts caused by dehydration and epoxy embedding in TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008599x ◽

1991 ◽

Vol 49 ◽

pp. 338-339

Author(s):

Hilton H. Mollenhauer

Keyword(s):

Electron Microscopy ◽

Electron Beam ◽

Volume Change ◽

Tissue Damage ◽

Beam Specimen ◽

Chemical Fixation ◽

Resin Impregnation ◽

Storage Vesicles ◽

A Cell ◽

Tissue Shrinkage

Various means have been devised to preserve biological specimens for electron microscopy, the most common being chemical fixation followed by dehydration and resin impregnation. It is intuitive, and has been amply demonstrated, that these manipulations lead to aberrations of many tissue elements. This report deals with three parts of this problem: specimen dehydration, epoxy embedding resins, and electron beam-specimen interactions. However, because of limited space, only a few points can be summarized.Dehydration: Tissue damage, or at least some molecular transitions within the tissue, must occur during passage of a cell or tissue to a nonaqueous state. Most obvious, perhaps, is a loss of lipid, both that which is in the form of storage vesicles and that associated with tissue elements, particularly membranes. Loss of water during dehydration may also lead to tissue shrinkage of 5-70% (volume change) depending on the tissue and dehydrating agent.

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Short-term volume and turgor regulation in yeast

Essays in Biochemistry ◽

10.1042/bse0450147 ◽

2008 ◽

Vol 45 ◽

pp. 147-160 ◽

Cited By ~ 12

Author(s):

Jörg Schaber ◽

Edda Klipp

Keyword(s):

Dynamic Model ◽

Volume Change ◽

Volume Regulation ◽

Time Course ◽

Osmotic Shock ◽

Intracellular Concentration ◽

Short Term ◽

Hydrodynamic Property ◽

Turgor Regulation ◽

Thermodynamic Framework

Volume is a highly regulated property of cells, because it critically affects intracellular concentration. In the present chapter, we focus on the short-term volume regulation in yeast as a consequence of a shift in extracellular osmotic conditions. We review a basic thermodynamic framework to model volume and solute flows. In addition, we try to select a model for turgor, which is an important hydrodynamic property, especially in walled cells. Finally, we demonstrate the validity of the presented approach by fitting the dynamic model to a time course of volume change upon osmotic shock in yeast.

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