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Martonová D, Holz D, Seufert J, Duong MT, Alkassar M, Leyendecker S. Comparison of stress and stress–strain approaches for the active contraction in a rat cardiac cycle model. J Biomech 2022; 134:110980. [DOI: 10.1016/j.jbiomech.2022.110980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/21/2022] [Accepted: 01/24/2022] [Indexed: 11/17/2022]
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Fukami H, Sunada K. Effects of vasopressin administration in the oral cavity on cardiac function and hemodynamics in rats. J Dent Anesth Pain Med 2022; 22:11-18. [PMID: 35169616 PMCID: PMC8814726 DOI: 10.17245/jdapm.2022.22.1.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/21/2021] [Accepted: 12/20/2021] [Indexed: 11/15/2022] Open
Abstract
Background The vasoconstrictive effect of epinephrine in local anesthetics affects the heart, which leads to hesitation among dentists in injecting local anesthetics into patients with cardiovascular disease. Due to its vasoconstrictive effects, the present study investigated the effects of vasopressin administration on cardiac function in rats. Methods Experiment 1 aimed to determine the vasopressin concentration that could affect cardiac function. An arterial catheter was inserted into the male Wistar rats. Next, 0.03, 0.3, and 3.0 U/mL arginine vasopressin (AVP) (0.03V, 0.3V, and 3.0V) was injected into the tongue, and the blood pressure was measured. The control group received normal saline only. In Experiment 2, following anesthesia infiltration, a pressure–volume catheter was placed in the left ventricle. Baseline values of end-systolic elastance, end-diastolic volume, end-systolic pressure, stroke work, stroke volume, and end-systolic elastance were recorded. Next, normal saline and 3.0V AVP were injected into the tongue to measure their effect on hemodynamic and cardiac function. Results After 3.0V administration, systolic blood pressures at 10 and 15 min were higher than those of the control group; they increased at 10 min compared with those at baseline. The diastolic blood pressures at 5–15 min were higher than those of the control group; they increased at 5 and 10 min compared with those at baseline. The preload decreased at 5 and 10 min compared to that at baseline. However, the afterload increased from 5 to 15 min compared with that of the control group; it increased at 10 min compared with that at baseline. Stroke volume decreased at 10 and 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Stroke work decreased from 5 to 15 min compared with that of the control group; it decreased from 5 to 15 min compared with that at baseline. Conclusion Our results showed that 3.0 U/mL concentration of vasopressin resulted in increased blood pressure, decreased stroke volume and stoke work, decreased preload and increased afterload, without any effect on myocardial contractility.
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Affiliation(s)
- Hayato Fukami
- Department of Dental Anesthesiology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan
| | - Katsuhisa Sunada
- Department of Dental Anesthesiology, School of Life Dentistry at Tokyo, The Nippon Dental University, Tokyo, Japan
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Chowdhury SM, Butts RJ, Taylor CL, Bandisode VM, Chessa KS, Hlavacek AM, Shirali GS, Baker GH. Validation of Noninvasive Measures of Left Ventricular Mechanics in Children: A Simultaneous Echocardiographic and Conductance Catheterization Study. J Am Soc Echocardiogr 2016; 29:640-7. [PMID: 27025669 DOI: 10.1016/j.echo.2016.02.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children. METHODS Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different methods. These estimates were calculated using a combination of noninvasive blood pressure readings, ventricular volumes derived from three-dimensional echocardiography, and Doppler time intervals. RESULTS Of 24 patients, 18 patients were heart transplant recipients, and six patients had small patent ductus arteriosus or small coronary fistulae. The mean age was 9.1 ± 5.6 years. The average invasive Ees was 3.04 ± 1.65 mm Hg/mL. Invasive Ees correlated best with echocardiographic Ees by the method of Tanoue (r = 0.85, P < .01), with a mean difference of -0.07 mm Hg/mL (95% limits of agreement, -2.0 to 1.4 mm Hg/mL). CONCLUSIONS Echocardiographic estimates of Ees correlate well with gold-standard measures obtained via conductance catheters in children with relatively normal loading conditions. The use of these noninvasive measures in accurately assessing left ventricular contractility appears promising and merits further study in children.
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Affiliation(s)
- Shahryar M Chowdhury
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina.
| | - Ryan J Butts
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
| | - Carolyn L Taylor
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
| | - Varsha M Bandisode
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
| | - Karen S Chessa
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
| | - Anthony M Hlavacek
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
| | - Girish S Shirali
- The Ward Family Heart Center, Children's Mercy Hospital, Kansas City, Missouri
| | - G Hamilton Baker
- Department of Pediatrics, Division of Cardiology, Medical University of South Carolina, Charleston, South Carolina
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Yotti R, Bermejo J, Benito Y, Sanz-Ruiz R, Ripoll C, Martínez-Legazpi P, del Villar CP, Elízaga J, González-Mansilla A, Barrio A, Bañares R, Fernández-Avilés F. Validation of noninvasive indices of global systolic function in patients with normal and abnormal loading conditions: a simultaneous echocardiography pressure-volume catheterization study. Circ Cardiovasc Imaging 2013; 7:164-72. [PMID: 24173273 DOI: 10.1161/circimaging.113.000722] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Noninvasive indices based on Doppler echocardiography are increasingly used in clinical cardiovascular research to evaluate left ventricular global systolic chamber function. Our objectives were to clinically validate ultrasound-based methods of global systolic chamber function to account for differences between patients in conditions of abnormal load, and to assess their sensitivity to load confounders. METHODS AND RESULTS Twenty-seven patients (8 dilated cardiomyopathy, 10 normal ejection fraction, and 9 end-stage liver disease) underwent simultaneous echocardiography and left heart catheterization with pressure-conductance instrumentation. The reference index, maximal elastance (Emax), was calculated from pressure-volume loop data obtained during acute inferior vena cava occlusion. A wide range of values were observed for left ventricular systolic chamber function (Emax: 2.8±1.0 mm Hg/mL), preload, and afterload. Among the noninvasive indices tested, the peak ejection intraventricular pressure difference showed the best correlation with Emax (R=0.75). A significant but weaker correlation with Emax was observed for ejection fraction (R=0.41), midwall fractional shortening (R=0.51), global circumferential strain (R=-0.53), and strain rate (R=-0.46). Longitudinal strain and strain rate failed to correlate with Emax, as did noninvasive single-beat estimations of this index. Principal component and multiple regression analyses demonstrated that peak ejection intraventricular pressure difference was less sensitive to load, whereas ejection fraction and longitudinal strain and strain rate were heavily influenced by afterload. CONCLUSIONS Current ultrasound methods have limited accuracy to characterize global left ventricular systolic chamber function in a given patient. The Doppler-derived peak ejection intraventricular pressure difference should be preferred for this purpose because it best correlates with the reference index and is more robust in conditions of abnormal load.
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Blaudszun G, Licker MJ, Morel DR. Preload-adjusted left ventricular dP/dtmax: a sensitive, continuous, load-independent contractility index. Exp Physiol 2013; 98:1446-56. [DOI: 10.1113/expphysiol.2013.073833] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Blaudszun G, Morel DR. Relevance of the volume-axis intercept, V0, compared with the slope of end-systolic pressure-volume relationship in response to large variations in inotropy and afterload in rats. Exp Physiol 2011; 96:1179-95. [PMID: 21890525 DOI: 10.1113/expphysiol.2011.059881] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The end-systolic pressure-volume relationship (ESPVR) is proposed and used as a reliable index of left ventricular (LV) contractility despite the fact that its afterload independence has been challenged. Furthermore, the physiological relevance of its volume-axis intercept, V(0), remains unclear. Systemic haemodynamics and pressure-volume loops obtained by inferior vena cava occlusion were recorded in 21 rats anaesthetized by isoflurane inhalation and instrumented with a conductance pressure-volume catheter in response to incremental I.V. doses of adrenaline, dobutamine, phenylephrine, metoprolol, papaverine and isoflurane inhalation. In conditions with large variations (± 100%) of both inotropy and afterload, infusion of negative inotropic drugs was associated with a dose-dependent rightward shift of ESPVR accompanied by a decrease in its slope (end-systolic elastance, E(es)), whereas positive inotropic agents produced an isolated decrease in V(0). With the predominant vasoactive drugs, there was a dose-dependent change in E(es) without major horizontal shifts, demonstrating that this slope mainly represents LV afterload rather than inotropy. When contractility was altered, V(0) was negatively correlated to the preload-adjusted contractility index, PAdP/dt(max), demonstrating that a reduced V(0) provides a good reflection of increased LV contractility. From these results, we computed a logarithmically adjusted E(es)/V(0) ratio, which resulted in reasonably strong concordance with PAdP/dt(max), including all the investigated drugs and dosages [n = 288; bias, 0.8 ± 16.2% (SD)]. Concordance with E(es) (bias, 7.2 ± 58.7%) or V(0) (bias, -0.6 ± 33.4%), used alone or with other commonly used contractility indices, was far less significant. In contrast to E(es), V(0) provides a relatively good LV contractility index because it is much less sensitive to afterload.
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Affiliation(s)
- Grégoire Blaudszun
- Department of Anaesthesiology, Pharmacology and Intensive Care, University Hospitals of Geneva, Geneva, Switzerland.
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Reymond P, Merenda F, Perren F, Rüfenacht D, Stergiopulos N. Validation of a one-dimensional model of the systemic arterial tree. Am J Physiol Heart Circ Physiol 2009; 297:H208-22. [PMID: 19429832 DOI: 10.1152/ajpheart.00037.2009] [Citation(s) in RCA: 362] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A distributed model of the human arterial tree including all main systemic arteries coupled to a heart model is developed. The one-dimensional (1-D) form of the momentum and continuity equations is solved numerically to obtain pressures and flows throughout the systemic arterial tree. Intimal shear is modeled using the Witzig-Womersley theory. A nonlinear viscoelastic constitutive law for the arterial wall is considered. The left ventricle is modeled using the varying elastance model. Distal vessels are terminated with three-element windkessels. Coronaries are modeled assuming a systolic flow impediment proportional to ventricular varying elastance. Arterial dimensions were taken from previous 1-D models and were extended to include a detailed description of cerebral vasculature. Elastic properties were taken from the literature. To validate model predictions, noninvasive measurements of pressure and flow were performed in young volunteers. Flow in large arteries was measured with MRI, cerebral flow with ultrasound Doppler, and pressure with tonometry. The resulting 1-D model is the most complete, because it encompasses all major segments of the arterial tree, accounts for ventricular-vascular interaction, and includes an improved description of shear stress and wall viscoelasticity. Model predictions at different arterial locations compared well with measured flow and pressure waves at the same anatomical points, reflecting the agreement in the general characteristics of the "generic 1-D model" and the "average subject" of our volunteer population. The study constitutes a first validation of the complete 1-D model using human pressure and flow data and supports the applicability of the 1-D model in the human circulation.
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Affiliation(s)
- Philippe Reymond
- Laboratory of Hemodynamics and Cardiovascular Technology, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
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Niederer SA, Smith NP. The role of the Frank-Starling law in the transduction of cellular work to whole organ pump function: a computational modeling analysis. PLoS Comput Biol 2009; 5:e1000371. [PMID: 19390615 PMCID: PMC2668184 DOI: 10.1371/journal.pcbi.1000371] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Accepted: 03/20/2009] [Indexed: 12/01/2022] Open
Abstract
We have developed a multi-scale biophysical electromechanics model of the rat left ventricle at room temperature. This model has been applied to investigate the relative roles of cellular scale length dependent regulators of tension generation on the transduction of work from the cell to whole organ pump function. Specifically, the role of the length dependent Ca(2+) sensitivity of tension (Ca(50)), filament overlap tension dependence, velocity dependence of tension, and tension dependent binding of Ca(2+) to Troponin C on metrics of efficient transduction of work and stress and strain homogeneity were predicted by performing simulations in the absence of each of these feedback mechanisms. The length dependent Ca(50) and the filament overlap, which make up the Frank-Starling Law, were found to be the two dominant regulators of the efficient transduction of work. Analyzing the fiber velocity field in the absence of the Frank-Starling mechanisms showed that the decreased efficiency in the transduction of work in the absence of filament overlap effects was caused by increased post systolic shortening, whereas the decreased efficiency in the absence of length dependent Ca(50) was caused by an inversion in the regional distribution of strain.
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Cheng HM, Yu WC, Sung SH, Wang KL, Chuang SY, Chen CH. Usefulness of systolic time intervals in the identification of abnormal ventriculo-arterial coupling in stable heart failure patients. Eur J Heart Fail 2008; 10:1192-200. [PMID: 19004668 DOI: 10.1016/j.ejheart.2008.09.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2007] [Revised: 06/01/2008] [Accepted: 09/08/2008] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The ratio of effective arterial elastance (Ea) to ventricular end-systolic elastance (Ees) indicates the status of ventriculo-arterial coupling. AIMS We investigated if systolic time intervals (pre-ejection period, PEP; ejection time, ET; and their ratio, PEP/ET) can be used to identify heart failure patients with abnormal ventriculo-arterial coupling. METHODS Age and sex-matched study subjects included 54 apparently healthy subjects with normal left ventricular (LV) function, and stable patients with LV diastolic (n=54) and systolic dysfunction (n=54). Ees and Ea were estimated non-invasively by echocardiography, and abnormal ventriculo-arterial coupling was defined as Ea/Ees>1.2. PEP, ET, and PEP/ET were measured automatically using electrocardiography, phonocardiography, and brachial pulse volume recording. RESULTS Ea/Ees>1.2 was present in 48.1% of subjects with systolic dysfunction. The PEP/ET was significantly associated with most parameters of LV structure and function, and Ea/Ees (r=0.67, p<0.001). Using PEP/ET> or =0.423 as cut point, the sensitivity and specificity to identify patients with Ea/Ees>1.2 were 85.7% and 84.3%, respectively for the whole population, and 84.6% and 78.6%, for patients with systolic dysfunction. CONCLUSION Abnormal ventriculo-arterial coupling was present in almost half of stable patients with systolic dysfunction. PEP/ET was useful in identifying such patients.
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Hsu SJ, Bouchard RR, Dumont DM, Wolf PD, Trahey GE. In vivo assessment of myocardial stiffness with acoustic radiation force impulse imaging. ULTRASOUND IN MEDICINE & BIOLOGY 2007; 33:1706-19. [PMID: 17698282 PMCID: PMC2117626 DOI: 10.1016/j.ultrasmedbio.2007.05.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 04/16/2007] [Accepted: 05/10/2007] [Indexed: 05/04/2023]
Abstract
Acoustic radiation force impulse (ARFI) imaging has been demonstrated to be capable of visualizing variations in local stiffness within soft tissue. Recent advances in ARFI beam sequencing and parallel imaging have shortened acquisition times and lessened transducer heating to a point where ARFI acquisitions can be executed at high frame rates on commercially available diagnostic scanners. In vivo ARFI images were acquired with a linear array placed on an exposed canine heart. The electrocardiogram (ECG) was also recorded. When coregistered with the ECG, ARFI displacement images of the heart reflect the expected myocardial stiffness changes during the cardiac cycle. A radio-frequency ablation was performed on the epicardial surface of the left ventricular free wall, creating a small lesion that did not vary in stiffness during a heartbeat, though continued to move with the rest of the heart. ARFI images showed a hemispherical, stiffer region at the ablation site whose displacement magnitude and temporal variation through the cardiac cycle were less than the surrounding untreated myocardium. Sequences with radiation force pulse amplitudes set to zero were acquired to measure potential cardiac motion artifacts within the ARFI images. The results show promise for real-time cardiac ARFI imaging.
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Affiliation(s)
- Stephen J Hsu
- Department of Biomedical Engineering, Duke University, Durham, NC, USA.
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