The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform
Stanley S. Hillman - One of the best experts on this subject based on the ideXlab platform.
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Posterior lymph Heart function in two species of anurans: analysis based on both in vivo pressure-Volume relationships by conductance manometry and ultrasound.
The Journal of experimental biology, 2010Co-Authors: Dane A. Crossley, Stanley S. HillmanAbstract:Rhinella marina and Lithobates catesbeianus have known differences in the capacity to mobilize lymph to stabilize blood Volume following dehydration and hemorrhage. The purpose of these experiments was to assess whether there are interspecific differences in basic lymph Heart functions. The end diastolic Volumes of posterior lymph Hearts averaged 10.8 μl kg⁻¹ in R. marina and 7.9-10.8 μl kg⁻¹ in L. catesbeianus by conductance manometry, and 9-32 μl kg⁻¹ in R. marina by ultrasound techniques, which correlated with body mass. Stroke Volumes were approximately 20% of end diastolic Volumes in both species. Peak systolic pressures and Stroke work were correlated with the index of contractility (dP/dt(max)) in both species. Stroke Volume was correlated to Stroke work but not peak systolic pressure, end diastolic Volume or end diastolic pressure indicating the preload variables do not seem to determine Stroke Volume as would be predicted from Starling considerations of the blood Heart. Renal portal elastance (end systolic pressure/Stroke Volume) an afterload index did not differ interspecifically, and was equivalent to values for systemic flow indices from mice of equivalent ventricular Volume. These data, taken together with predictions derived from mammalian models on the effect of high resistance indicate afterload (renal portal pressure), may be important determinants of posterior lymph Heart Stroke Volume. The shape of the pressure-Volume loop is different from an idealized version previously reported, and is influenced by end diastolic Volume. Our data indicate that increasing end diastolic pressure and Volume can influence the loop shape but not the Stroke Volume. This indicates that lymph Hearts do not behave in a Starling Law manner with increased preload Volume.
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Posterior lymph Heart function in two species of anurans: analysis based on both in vivo pressure–Volume relationships by conductance manometry and ultrasound
Journal of Experimental Biology, 2010Co-Authors: Dane A. Crossley, Stanley S. HillmanAbstract:Rhinella marina and Lithobates catesbeianus have known differences in the capacity to mobilize lymph to stabilize blood Volume following dehydration and hemorrhage. The purpose of these experiments was to assess whether there are interspecific differences in basic lymph Heart functions. The end diastolic Volumes of posterior lymph Hearts averaged 10.8 μl kg⁻¹ in R. marina and 7.9-10.8 μl kg⁻¹ in L. catesbeianus by conductance manometry, and 9-32 μl kg⁻¹ in R. marina by ultrasound techniques, which correlated with body mass. Stroke Volumes were approximately 20% of end diastolic Volumes in both species. Peak systolic pressures and Stroke work were correlated with the index of contractility (dP/dt(max)) in both species. Stroke Volume was correlated to Stroke work but not peak systolic pressure, end diastolic Volume or end diastolic pressure indicating the preload variables do not seem to determine Stroke Volume as would be predicted from Starling considerations of the blood Heart. Renal portal elastance (end systolic pressure/Stroke Volume) an afterload index did not differ interspecifically, and was equivalent to values for systemic flow indices from mice of equivalent ventricular Volume. These data, taken together with predictions derived from mammalian models on the effect of high resistance indicate afterload (renal portal pressure), may be important determinants of posterior lymph Heart Stroke Volume. The shape of the pressure-Volume loop is different from an idealized version previously reported, and is influenced by end diastolic Volume. Our data indicate that increasing end diastolic pressure and Volume can influence the loop shape but not the Stroke Volume. This indicates that lymph Hearts do not behave in a Starling Law manner with increased preload Volume.
Dane A. Crossley - One of the best experts on this subject based on the ideXlab platform.
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Posterior lymph Heart function in two species of anurans: analysis based on both in vivo pressure-Volume relationships by conductance manometry and ultrasound.
The Journal of experimental biology, 2010Co-Authors: Dane A. Crossley, Stanley S. HillmanAbstract:Rhinella marina and Lithobates catesbeianus have known differences in the capacity to mobilize lymph to stabilize blood Volume following dehydration and hemorrhage. The purpose of these experiments was to assess whether there are interspecific differences in basic lymph Heart functions. The end diastolic Volumes of posterior lymph Hearts averaged 10.8 μl kg⁻¹ in R. marina and 7.9-10.8 μl kg⁻¹ in L. catesbeianus by conductance manometry, and 9-32 μl kg⁻¹ in R. marina by ultrasound techniques, which correlated with body mass. Stroke Volumes were approximately 20% of end diastolic Volumes in both species. Peak systolic pressures and Stroke work were correlated with the index of contractility (dP/dt(max)) in both species. Stroke Volume was correlated to Stroke work but not peak systolic pressure, end diastolic Volume or end diastolic pressure indicating the preload variables do not seem to determine Stroke Volume as would be predicted from Starling considerations of the blood Heart. Renal portal elastance (end systolic pressure/Stroke Volume) an afterload index did not differ interspecifically, and was equivalent to values for systemic flow indices from mice of equivalent ventricular Volume. These data, taken together with predictions derived from mammalian models on the effect of high resistance indicate afterload (renal portal pressure), may be important determinants of posterior lymph Heart Stroke Volume. The shape of the pressure-Volume loop is different from an idealized version previously reported, and is influenced by end diastolic Volume. Our data indicate that increasing end diastolic pressure and Volume can influence the loop shape but not the Stroke Volume. This indicates that lymph Hearts do not behave in a Starling Law manner with increased preload Volume.
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Posterior lymph Heart function in two species of anurans: analysis based on both in vivo pressure–Volume relationships by conductance manometry and ultrasound
Journal of Experimental Biology, 2010Co-Authors: Dane A. Crossley, Stanley S. HillmanAbstract:Rhinella marina and Lithobates catesbeianus have known differences in the capacity to mobilize lymph to stabilize blood Volume following dehydration and hemorrhage. The purpose of these experiments was to assess whether there are interspecific differences in basic lymph Heart functions. The end diastolic Volumes of posterior lymph Hearts averaged 10.8 μl kg⁻¹ in R. marina and 7.9-10.8 μl kg⁻¹ in L. catesbeianus by conductance manometry, and 9-32 μl kg⁻¹ in R. marina by ultrasound techniques, which correlated with body mass. Stroke Volumes were approximately 20% of end diastolic Volumes in both species. Peak systolic pressures and Stroke work were correlated with the index of contractility (dP/dt(max)) in both species. Stroke Volume was correlated to Stroke work but not peak systolic pressure, end diastolic Volume or end diastolic pressure indicating the preload variables do not seem to determine Stroke Volume as would be predicted from Starling considerations of the blood Heart. Renal portal elastance (end systolic pressure/Stroke Volume) an afterload index did not differ interspecifically, and was equivalent to values for systemic flow indices from mice of equivalent ventricular Volume. These data, taken together with predictions derived from mammalian models on the effect of high resistance indicate afterload (renal portal pressure), may be important determinants of posterior lymph Heart Stroke Volume. The shape of the pressure-Volume loop is different from an idealized version previously reported, and is influenced by end diastolic Volume. Our data indicate that increasing end diastolic pressure and Volume can influence the loop shape but not the Stroke Volume. This indicates that lymph Hearts do not behave in a Starling Law manner with increased preload Volume.
Saeed Ranjbar - One of the best experts on this subject based on the ideXlab platform.
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A novel quantitative indicator of the left ventricular contraction based on Volume changes of the left ventricular myocardial segments
arXiv: Medical Physics, 2018Co-Authors: Mersedeh Karvandi, Saeed RanjbarAbstract:Ejection fraction (EF) is commonly measured by echocardiography, by dividing the Volume ejected by the Heart (Stroke Volume) by the Volume of the filled Heart (end-diastolic Volume). Utilizing Volume changes of left myocardial segments per a cardiac cycle, physical laws and mathematical equations specific echocardiographic data, this paper serves to generalize EF by a novel parameter over the time that it can make available, more detailed, valuable and practical information to fully describe the left ventricular (LV) contractility function.Patients who underwent clinically-directed standard transthoracic echocardiography using 2D conventional echocardiography machines armed to measuring strain components, were asked to estimate displacements and longitudinal, radial and circumferential strains for each LV echocardiographic segments per a cardiac cycle. Volume fractional changes of the LV echocardiographic segments are expanded based on their strain components over the time. Ejected blood Volume fraction induced by a left myocardial sample, is computed within a cardiac cycle. Total fraction of the ejected blood Volume in the left ventricular cavity was obtained by integrating over the times and LV myocardial segments. EF is an especial value of this total fraction at the end systolic time. The common measurement of EF is only based on LV cavity Volumes at the end diastolic and systolic phases. These findings lead to determine detailed aspects of the left ventricular contraction. This generalized parameter has important implications to give the real value of EF in the sever Mitral valve regurgitations.
Mersedeh Karvandi - One of the best experts on this subject based on the ideXlab platform.
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A novel quantitative indicator of the left ventricular contraction based on Volume changes of the left ventricular myocardial segments
arXiv: Medical Physics, 2018Co-Authors: Mersedeh Karvandi, Saeed RanjbarAbstract:Ejection fraction (EF) is commonly measured by echocardiography, by dividing the Volume ejected by the Heart (Stroke Volume) by the Volume of the filled Heart (end-diastolic Volume). Utilizing Volume changes of left myocardial segments per a cardiac cycle, physical laws and mathematical equations specific echocardiographic data, this paper serves to generalize EF by a novel parameter over the time that it can make available, more detailed, valuable and practical information to fully describe the left ventricular (LV) contractility function.Patients who underwent clinically-directed standard transthoracic echocardiography using 2D conventional echocardiography machines armed to measuring strain components, were asked to estimate displacements and longitudinal, radial and circumferential strains for each LV echocardiographic segments per a cardiac cycle. Volume fractional changes of the LV echocardiographic segments are expanded based on their strain components over the time. Ejected blood Volume fraction induced by a left myocardial sample, is computed within a cardiac cycle. Total fraction of the ejected blood Volume in the left ventricular cavity was obtained by integrating over the times and LV myocardial segments. EF is an especial value of this total fraction at the end systolic time. The common measurement of EF is only based on LV cavity Volumes at the end diastolic and systolic phases. These findings lead to determine detailed aspects of the left ventricular contraction. This generalized parameter has important implications to give the real value of EF in the sever Mitral valve regurgitations.
Antonio Fernandes Moron - One of the best experts on this subject based on the ideXlab platform.
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Fetal cardiac function assessed by spatio-temporal image correlation
Archives of Gynecology and Obstetrics, 2011Co-Authors: Christiane Simioni, Luciano Marcondes Machado Nardozza, Liliam Cristine Rolo, O. Terasaka, Marina Maccagnano Zamith, Edward Araujo Júnior, Antonio Fernandes MoronAbstract:Background Three-dimensional (3D) and four-dimensional (4D) ultrasound have been proposed to be valuable tools for the examination of fetal Heart. Spatio-temporal image correlation (STIC) is a technique that adds a time component to 3D ultrasound imaging of the fetal Heart, so we can evaluate cardiac structures as a 4D cine sequence containing information of one full cardiac cycle. STIC gives the investigator the opportunity to freeze the displayed cardiac loop in end-diastolic and end-systolic phases. By STIC, 3D measurements of both the left and right ventricle can be used to calculate fetal Heart Stroke Volume, cardiac output and ejection fraction, and expressions of cardiac function. The ultimate goal of STIC technique is to improve fetal cardiac function analysis by decreasing the dependency on operator skills required by two-dimensional ultrasound. Context In this article, we describe literature practical approach for the examination of the fetal Heart function using 4D ultrasound by STIC technique.
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Heart Stroke Volume, cardiac output, and ejection fraction in 265 normal fetus in the second half of gestation assessed by 4D ultrasound using spatio-temporal image correlation.
The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine the Federation of Asia and , 2011Co-Authors: Christiane Simioni, Luciano Marcondes Machado Nardozza, Edward Araujo Júnior, Liliam Cristine Rolo, Marina Maccagnano Zamith, Ana Carolina Rabachini Caetano, Antonio Fernandes MoronAbstract:Objectives. The aim of this study was to establish nomograms for fetal Stroke Volume (SV), cardiac output (CO), and ejection fraction (EF) using four-dimensional ultrasound with spatio-temporal image correlation (STIC) modality.Methods. The fetal Heart was scanned using STIC modality, starting with classic four-chamber view plane, during fetal quiescence with abdomen uppermost, at an angle of 20–30°, without color Doppler flow mapping. In post-processing virtual organ, computer-aided analysis technique was used to obtain a sequence of six sections of each ventricular Volume in end-systolic Volume (ESV) and end-diastolic Volume (EDV). The SV (SV = EDV–ESV), CO (CO = SV × fetal Heart rate), and EF (EF = SV/EDV) for each ventricle were then calculated. Intra- and interobserver agreement were then calculated.Results. Two hundred sixty-five fetuses, ranging in gestational age (GA) from 20 to 34+6 weeks, were included in the study. The left and right SV and CO increased exponentially with gestation and EF remai...
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Fetal cardiac function assessed by spatio-temporal image correlation
Archives of gynecology and obstetrics, 2010Co-Authors: Christiane Simioni, Luciano Marcondes Machado Nardozza, Edward Araujo Júnior, Liliam Cristine Rolo, O. Terasaka, Marina Maccagnano Zamith, Antonio Fernandes MoronAbstract:Background Three-dimensional (3D) and four-dimensional (4D) ultrasound have been proposed to be valuable tools for the examination of fetal Heart. Spatio-temporal image correlation (STIC) is a technique that adds a time component to 3D ultrasound imaging of the fetal Heart, so we can evaluate cardiac structures as a 4D cine sequence containing information of one full cardiac cycle. STIC gives the investigator the opportunity to freeze the displayed cardiac loop in end-diastolic and end-systolic phases. By STIC, 3D measurements of both the left and right ventricle can be used to calculate fetal Heart Stroke Volume, cardiac output and ejection fraction, and expressions of cardiac function. The ultimate goal of STIC technique is to improve fetal cardiac function analysis by decreasing the dependency on operator skills required by two-dimensional ultrasound.
