Nonlinear dynamics modeling of mechanical periodicity of end diastolic volume of left ventricle

2001 ◽  
Vol 22 (10) ◽  
pp. 1183-1191
Author(s):  
Xu Shi-xiong ◽  
Mao Xiao-chun
Keyword(s):  
Nonlinear Dynamics ◽  
Left Ventricle ◽  
Dynamics Modeling ◽  
End Diastolic Volume ◽  
Mechanical Periodicity

Non-linear dynamic simulation of mechanical periodicity of end-diastolic volume of left ventricle under the influence of baroreflex

2006 ◽  
Vol 220 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Q Wang ◽  
S Xu ◽  
D Chen ◽  
M Collins
Keyword(s):  
Left Ventricle ◽  
Vascular System ◽  
Element Model ◽  
Baroreceptor Reflex ◽  
Lumped Parameter Model ◽  
Linear Dynamic ◽  
End Diastolic Volume ◽  
Lumped Parameter ◽  
Non Linear ◽  
Mechanical Periodicity

Mechanical periodicity (MP) of the end-diastolic volume (EDV) of the left ventricle (LV) is closely associated with cardiovascular pathophysiology. On the basis of the Starling's law of the LV and Burattini and Gnudi's four-element model of the vascular system, and considering baroreceptor reflex, a non-linear dynamic lumped-parameter model is proposed. This simulates the MP phenomena of the EDV by solving a series of one-dimensional discrete non-linear dynamic equations. The results demonstrate that excessive deviations of some physiological parameters often induce MP - the unstable phenomena of EDV - and verify that the effects of baroreceptor reflex enhance the ability of the human physiological system to maintain stability.

Biplane ventriculography in the rat

1986 ◽  
Vol 250 (1) ◽  
pp. H131-H136
Author(s):  
J. L. Heckman ◽  
L. Garvin ◽  
T. Brown ◽  
W. Stevenson-Smith ◽  
W. P. Santamore ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Left Ventricle ◽  
Ejection Fraction ◽  
Stroke Volume ◽  
Methyl Methacrylate ◽  
High Speed ◽  
Water Displacement ◽  
Systolic Volume ◽  
End Diastolic Volume ◽  
End Systolic Volume

Biplane ventriculography was performed on nine intact anesthetized rats. Images of the left ventricle large enough for analysis were obtained by placing the rats close to the radiographic tubes (direct enlargement). Sampling rates, adequate for heart rates of 500 beats/min, were obtained by filming at 500 frames/s. From the digitized silhouettes of the left ventricle the following information was obtained (means +/- SE): end-diastolic volume 0.60 +/- 0.03 ml, end-systolic volume 0.22 +/- 0.02 ml, stroke volume 0.38 +/- 0.02 ml, ejection fraction 0.63 +/- 0.02, cardiac output 118 +/- 7 ml/min, diastolic septolateral dimension 0.41 +/- 0.01 mm, diastolic anteroposterior dimension 0.40 +/- 0.01 mm, diastolic base-to-apex dimension 1.58 +/- 0.04 mm. To determine the accuracy with which the volume of the ventricle could be measured, 11 methyl methacrylate casts of the left ventricle were made. The correlation was high (r = 0.99 +/- 0.02 ml E) between the cast volumes determined by water displacement and by use of two monoplane methods (Simpson's rule of integration and the area-length method applied to the analysis of the anteroposterior films) and a biplane method (area-length). These results demonstrate that it is possible to obtain accurate dimensions and volumes of the rat left ventricle by use of high-speed ventriculography.

scholarly journals Cardiac involvement in patients with coronavirus pneumonia

2021 ◽  
Vol 20 (Supplement_1) ◽  
Author(s):  
O Germanova ◽  
O Tereshina
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Left Atrium ◽  
Longitudinal Strain ◽  
Cardiac Involvement ◽  
Mean Value ◽  
Systolic Pulmonary Artery Pressure ◽  
Functional Changes ◽  
End Diastolic Volume ◽  
The Mean

Abstract Funding Acknowledgements Type of funding sources: None. Background. New COVID-19 disease is well known by its primary damage of respiratory system. However, it is also possible to involve other organs and systems. Purpose. To determine the cardiac involvement in patients with COVID-19 pneumonia. Materials and methods. We performed echocardiography with speckle tracking in 48 patients. All of them had serologically verified COVID-19 pneumonia with lung involvement 5-60% on CT. None of them were treated by antimalarial drugs. 28 of them were men and 20 women, mean age - 45 ± 4,4 years old. We performed echocardiography in 1 month period from onset of the disease. Results. Most of the patients (30 patients) had enlargement of right heart chambers. Despite of right ventricle enlargement, in none of the patients had reduced right ventricle function (TAPSE 22 ± 2 mm, right ventricle strain -21,2 ± 1,5%). The mean systolic pulmonary artery pressure was slightly elevated (38 ± 2 mm Hg). Left ventricle was enlarged in 9 patients (with mean end diastolic volume 82 ± 5 ml/m2). In 25 of them, the ejection fraction was decreased (44 ± 4%). In all patients with COVID-19 pneumonia, the changes in circumferential and longitudinal strain were observed. Both parameters were decreased. The mean value of circumferential strain was -16,3 ± 1,9%. The longitudinal strain parameter was -14,2 ± 1,4%. 25 patients had enlargement of left atrium (>40ml/m2) and the reservoir strain of left atrium was decreased (-23,3 ± 1,5%)  in 29 of them. After 2 months from the onset of the disease, we noticed the normalization of echocardiography data in all patients. Nevertheless, we observed cardiac structural and functional changes in all patients, troponins levels were increased only in 12 patients. Conclusion. We observed cardiac involvement in different degree in all of patients with COVID-19 pneumonia. Changes characterized by atriums and ventricles enlargement, and left ventricle contractile dysfunction.  Due to the fact that only part of the patients with COVID-19 with cardiac changes had elevated troponins, we believe that the mechanism of these pathological changes need further research.

Nonlinear dynamics modeling and performance prediction for underactuated AUV with fins

2015 ◽  
Vol 84 (1) ◽  
pp. 237-249 ◽  
Author(s):  
Xiao Liang ◽  
Ye Li ◽  
Zhouhua Peng ◽  
Jundong Zhang
Keyword(s):  
Nonlinear Dynamics ◽  
Performance Prediction ◽  
Dynamics Modeling ◽  
Underactuated Auv ◽  
And Performance

Algorithm for diagnosis and typing of ALCAPA syndrome

2021 ◽  
Vol 3 (2) ◽  
pp. 01-07
Author(s):  
Mariela Céspedes Almira ◽  
Adel Eladio González Morejón ◽  
Giselle Serrano Ricardo ◽  
Tania Rosa González Rodríguez ◽  
Judith Escobar Bermúdez
Keyword(s):  
Coronary Artery ◽  
Left Ventricle ◽  
Left Coronary Artery ◽  
Cross Sectional Study ◽  
Left Ventricular ◽  
Volume Index ◽  
Cross Sectional ◽  
End Diastolic Volume ◽  
Congenital Origin ◽  
Diagnostic Modalities

ALCAPA syndrome was characterized by anomalous origin of left coronary artery from pulmonary artery. Its clinical presentation is varied and although it is an anomaly of congenital origin, it is not exclusive to pediatric ages. Its epidemiological documentation is difficult. We aimed to make the non-invasive diagnosis of the ALCAPA syndrome and its variants. An observational, prospective and cross-sectional study was conducted with 31 patients with a positive echocardiographic diagnosis of ALCAPA syndrome at Pediatric Cardio Center “William Soler” from 2005 to 2018. The variables with significance for diagnosis were the echocardiographic visualization of the anomalous connection and the reversed flow in the left coronary artery. The variables with significance for typing were age at diagnosis, ischemia in the electrocardiogram, echocardiographic visualization of left ventricle papillary muscles fibrosis, presence of severe mitral regurgitation, left ventricle spheroidal remodeling, left ventricle ejection fraction, left ventricular end-diastolic volume index, and left ventricular end-diastolic diameter index. An algorithm integrated by various diagnostic modalities associated with echocardiography as a tool for the detection of ALCAPA was developed. The documentation of the diagnostic and classificatory aspects of the syndrome is possible by detecting echocardiographic elements in conjunction with electrocardiographic and radiological aspects.

Computational Modeling of Human Left Ventricle to Assess the Effects of Trabeculae Carneae on the Diastolic and Systolic Functions

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Fatemeh Fatemifar ◽  
Marc D. Feldman ◽  
Geoffrey D. Clarke ◽  
Ender A. Finol ◽  
Hai-Chao Han
Keyword(s):  
Left Ventricle ◽  
Systolic Function ◽  
Strain Energy Function ◽  
Patient Specific ◽  
Papillary Muscles ◽  
End Diastolic Volume ◽  
Wall Stiffness ◽  
Biaxial Tests ◽  
Cutting Model

Trabeculae carneae are irregular structures that cover the endocardial surfaces of both ventricles and account for a significant portion of human ventricular mass. The role of trabeculae carneae in diastolic and systolic functions of the left ventricle (LV) is not well understood. Thus, the objective of this study was to investigate the functional role of trabeculae carneae in the LV. Finite element (FE) analyses of ventricular functions were conducted for three different models of human LV derived from high-resolution magnetic resonance imaging (MRI). The first model comprised trabeculae carneae and papillary muscles, while the second model had papillary muscles and partial trabeculae carneae, and the third model had a smooth endocardial surface. We customized these patient-specific models with myofiber architecture generated with a rule-based algorithm, diastolic material parameters of Fung strain energy function derived from biaxial tests and adjusted with the empirical Klotz relationship, and myocardial contractility constants optimized for average normal ejection fraction (EF) of the human LV. Results showed that the partial trabeculae cutting model had enlarged end-diastolic volume (EDV), reduced wall stiffness, and even increased end-systolic function, indicating that the absence of trabeculae carneae increased the compliance of the LV during diastole, while maintaining systolic function.

External mechanical work during relaxation period does not affect myocardial oxygen consumption

1991 ◽  
Vol 261 (6) ◽  
pp. H1778-H1784 ◽  
Author(s):  
K. Hata ◽  
Y. Goto ◽  
H. Suga
Keyword(s):  
Oxygen Consumption ◽  
Left Ventricle ◽  
Potential Energy ◽  
Myocardial Oxygen Consumption ◽  
Mechanical Work ◽  
Relaxation Period ◽  
End Diastolic Volume ◽  
The Cross

We assessed the effect of external mechanical work (EW) during the relaxation period (RP) on myocardial oxygen consumption (VO2) and clarified the energetic significance of the potential energy (PE) portion of the pressure-volume area (PVA) in the cross-circulated dog left ventricle. We changed the course of the relaxation segment of the pressure-volume (P-V) trajectory by increasing or decreasing EW within a given PVA without changing the end-diastolic volume (EDV) and the systolic segment of the P-V trajectory while measuring VO2. Thus the ventricle underwent ejection or filling during RP. Although the percent fraction of EW in PVA (%EW/PVA) was markedly increased from 32 +/- 12 (SD) to 93 +/- 3% in ejecting contractions (8 hearts) and from 0 to 93 +/- 5% in isovolumic contractions (3 hearts), these marked changes in %EW/PVA did not significantly affect VO2. Moreover, the VO2-PVA data during these procedures fell on the reference VO2-PVA relation line obtained by changing EDV and PVA of isovolumic contractions. We conclude that EW during RP at a constant PVA does not affect VO2 and part of PE can be converted into EW in an energetically equivalent manner.

Left Intraventricular Balloon Pump Optimization during Intractable Cardiac Arrest

1996 ◽  
Vol 19 (7) ◽  
pp. 422-430 ◽  
Author(s):  
S.F. Stamatelopoulos ◽  
L. Kochilas ◽  
N.S. Saridakis ◽  
N.A. Zakopoulos ◽  
S.D. Moulopoulos
Keyword(s):  
Cardiac Arrest ◽  
Left Ventricle ◽  
Aortic Pressure ◽  
Left Ventricular ◽  
Hemodynamic Effect ◽  
Dog Heart ◽  
End Diastolic Volume

This work aims to determine optimal balloon shape and volume during left intraventricular balloon pumping (IABP) in the fibrillating dog heart. A balloon volume equal to the left ventricular end-diastolic volume (LVEDV) maintained a higher systolic aortic pressure and flow (106.4 ± 2.7 mmHg and 84.7 ± 2.35 ml/kg/min, x ± SEM, respectively) than a 25% smaller (97.8 ± 3.3 mmHg, P=0.002 and 63.7 ± 4.1 ml/Kg/min, P=0.002, respectively) or a 25% larger balloon (87.4 ± 2.3 mmHg, P=0.002 and 70.9 ± 3.4 ml/kg/min, P=0.002, respectively). Among 5 different balloon shapes tested, a pear-shaped balloon inflated from the apex to the base of the left ventricle induced the highest (P varying from 0.042 to 0.01, compared to the remaining balloon shapes) systolic aortic pressure and flow (104.6 ± 4.5 mmHg and 77.9 ± 1.7 mg/kg/min, respectively). In conclusion, a pear shaped balloon, inflated to a volume equal to the LVEDV, from the apex to the base of the left ventricle, induced an optimal hemodynamic effect during LVBP.

scholarly journals 1180 2D and 3D assessment of the left ventricle volume and ejection fraction in a general population

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
F Ericsson ◽  
B Tayal ◽  
K Hay Kragholm ◽  
T Zaremba ◽  
N Holmark Andersen ◽  
...  
Keyword(s):  
General Population ◽  
Left Ventricle ◽  
Ejection Fraction ◽  
Large Population ◽  
Systolic Volume ◽  
End Diastolic Volume ◽  
Significant Difference ◽  
End Systolic Volume ◽  
The Mean ◽  
2D And 3D

Abstract Introduction In standard practice, LV volumes and EF are estimated by 2D technique. 3D echocardiographic assessment seems more reliable; however, this method has not yet been validated in the general population. Purpose To validate 3D echocardiography in a large population sample and investigate differences between 2D and 3D LVEF and volumes Methods In The Copenhagen City Heart Study, 4466 echocardiograms were available for analysis. The echocardiograms were obtained during four consecutive heartbeats in both 2D and 3D with GE Vivid E9. Offline analysis was performed on EchoPac v. 201. LVEF was calculated by the modified Simpsons Biplane Auto EF for 2D and by the 4LVQ method for 3D. Results The study included 2090 echocardiograms. The mean 2D LVEF was 57.3 ± 6.1% (IQR 54 - 61%) and 51.7 ± 7.9% (IQR 47 - 57%) by 3D. The mean end-diastolic volume (EDV) and end-systolic volume (ESV) by 2D and 3D techniques were: EDV 2D 106.1 ± 29.6 ml vs EDV 3D 128.2 ± 32.3 ml , ESV 2D 45.7 ± 15.6 ml vs. ESV 3D 45.7 ± 20.7 , p < 0.05 among all variables. The average difference of means between 2D and 3D LVEF was 5.6 ± 11.2%, -22.1 ± 56.8 ml for EDV, and -16.9 ± 32.9 ml for ESV. The correlation coefficient for LVEF was 0.42, EDV 0.76 and for ESV 0.70. Conclusion In our study, we found a significant difference in both LVEF and ventricular volumes when comparing 2D echocardiograms with 3D. 3DE had, in general, lower LVEF, higher EDV and ESV compared to 2D. Table 1: Summary of results Table 1 - Summary of results n = 2090 Variable Min Max Mean IQR (25-75) p-value LVEF, 2D (%) 18 76 57.3 ± 6.1 54-61 < 0.05 LVEF, 3d (%) 13 77 51.7 ± 7.9 47-57 < 0.05 EDV, 2D (ml) 13 275 106.1 ± 29.6 85-123.8 < 0.05 EDV, 3D (ml) 50 270 128.2 ± 32.3 106-148 < 0.05 ESV, 2D (ml) 15 150 45.7 ± 15.6 35-54 < 0.05 ESV, 3D (ml) 13 185 45.7 ± 20.7 48-74 < 0.05 LVEF: left ventricle ejection fraction, EDV: end-diastolic volume, ESV: end systolic volume, IQR: Inter-quartile range Abstract 1180 Figure 1: Correlation and BA-plot

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