1
|
Téllez L, Ibáñez-Samaniego L, Pérez Del Villar C, Yotti R, Martínez J, Carrión L, Rodríguez de Santiago E, Rivera M, González-Mansilla A, Pastor Ó, Bermejo J, Bañares R, Albillos A. Non-selective beta-blockers impair global circulatory homeostasis and renal function in cirrhotic patients with refractory ascites. J Hepatol 2020; 73:1404-1414. [PMID: 32446716 DOI: 10.1016/j.jhep.2020.05.011] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/27/2020] [Accepted: 05/07/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND & AIMS The safety of non-selective β-blockers (NSBBs) has been questioned in refractory ascites (RA). We studied the effects of NSBBs on cardiac systolic function, systemic hemodynamics, and renal perfusion pressure (RPP) and function in patients with diuretic-responsive ascites (DRA) and RA. METHODS We performed a prospective pre-post repeated-measures study in cirrhotic patients, 18 with DRA and 20 with RA on NSBBs for variceal bleeding prophylaxis. Systolic function (by ejection intraventricular pressure difference [EIVPD]), hepatic venous pressure gradient (HVPG), cardiopulmonary pressures, RPP, and sympathetic activation were measured at baseline and after 4 weeks of propranolol. RESULTS EIVPD was elevated at baseline (RA 4.5 [2.8-5.7] and DRA 4.2 [3.1-5.7] mmHg; normal 2.4-3.6 mmHg) and directly related to the severity of vasodilation and sympathetic activation. NSBBs led to similar reductions in heart rate and HVPG in both groups. NSBBs reduced EIPVD in RA but not in DRA (-20% vs. -2%, p <0.01). In RA, the NSBB-induced reduction in EIPVD correlated with the severity of vasodilation and with higher plasma nitric oxide, norepinephrine and IL-6 (r >0.40, all p <0.05). NSBBs reduced RPP in both groups, but impaired renal function only in patients with RA. Reduced EIPVD correlated with decreases in RPP and estimated glomerular filtration rate (r >0.40, all p <0.01). After NSBB treatment, RPP dropped below the threshold of renal flow autoregulation in 11 of the 20 (55%) patients with RA, including the 4 fulfilling the criteria for HRS-AKI. CONCLUSION Renal perfusion and function depend critically on systolic function and sympathetic hyperactivation in RA. NSBBs blunt the sympathetic overdrive, hamper cardiac output, lower RPP below the critical threshold and impair renal function. β-blockade should be used cautiously or even avoided in patients with RA. LAY SUMMARY We have identified the mechanisms by which non-selective beta-blockers could impair survival in patients with refractory ascites. We show that peripheral vasodilation and sympathetic activation lead to increased left ventricle systolic function in patients with cirrhosis and ascites, which acts as an adaptive mechanism to maintain renal perfusion. When ascites becomes refractory, this compensatory cardiac response to vasodilation is critically dependent on sympathetic hyperactivation and is hardly able to maintain renal perfusion. In this setting, β-blockade blunts the sympathetic overdrive of cardiac function, hampers cardiac output, lowers renal perfusion pressure below the critical threshold and impairs renal function.
Collapse
Affiliation(s)
- Luis Téllez
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBEREHD, Universidad de Alcalá, Madrid, Spain
| | - Luis Ibáñez-Samaniego
- Department of Digestive Diseases, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBEREHD, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Candelas Pérez Del Villar
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBERCV, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Raquel Yotti
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBERCV, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Javier Martínez
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBEREHD, Universidad de Alcalá, Madrid, Spain
| | - Laura Carrión
- Department of Digestive Diseases, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBEREHD, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Enrique Rodríguez de Santiago
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBEREHD, Universidad de Alcalá, Madrid, Spain
| | - Maite Rivera
- Department of Nephrology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Universidad de Alcalá, Madrid, Spain
| | - Ana González-Mansilla
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBERCV, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Óscar Pastor
- Servicio de Bioquímica Clínica, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBEROBN, Universidad de Alcalá, Madrid, Spain
| | - Javier Bermejo
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBERCV, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Rafael Bañares
- Department of Digestive Diseases, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón (iISGM), CIBEREHD, and Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Agustín Albillos
- Department of Gastroenterology and Hepatology, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), CIBEREHD, Universidad de Alcalá, Madrid, Spain.
| |
Collapse
|
2
|
Wang LW, Kesteven SH, Huttner IG, Feneley MP, Fatkin D. High-Frequency Echocardiography ― Transformative Clinical and Research Applications in Humans, Mice, and Zebrafish ―. Circ J 2018; 82:620-628. [DOI: 10.1253/circj.cj-18-0027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Louis W. Wang
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute
- St Vincent’s Hospital
- Faculty of Medicine, UNSW Sydney
| | - Scott H. Kesteven
- Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute
| | - Inken G. Huttner
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute
- St Vincent’s Hospital
- Faculty of Medicine, UNSW Sydney
| | - Michael P. Feneley
- Cardiac Physiology and Transplantation Division, Victor Chang Cardiac Research Institute
- St Vincent’s Hospital
- Faculty of Medicine, UNSW Sydney
| | - Diane Fatkin
- Molecular Cardiology Division, Victor Chang Cardiac Research Institute
- St Vincent’s Hospital
- Faculty of Medicine, UNSW Sydney
| |
Collapse
|
3
|
Chi Q, He Y, Luan Y, Qin K, Mu L. Numerical analysis of wall shear stress in ascending aorta before tearing in type A aortic dissection. Comput Biol Med 2017; 89:236-247. [DOI: 10.1016/j.compbiomed.2017.07.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 07/13/2017] [Accepted: 07/30/2017] [Indexed: 11/16/2022]
|
4
|
LE THUTHAO, TAN RUSAN, HUANG FEIQIONG, ZHONG LIANG, IDAPALAPATI SRIDHAR, GHISTA DHANJOO. INTRA-LEFT VENTRICULAR FLOW DISTRIBUTIONS IN DIASTOLIC AND SYSTOLIC PHASES, BASED ON ECHO VELOCITY FLOW MAPPING OF NORMAL SUBJECTS AND HEART FAILURE PATIENTS, TO CHARACTERIZE LEFT VENTRICULAR PERFORMANCE OUTCOMES OF HEART FAILURE. J MECH MED BIOL 2012. [DOI: 10.1142/s0219519412400295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heart failure (HF), one of the most common diseases in the world, causes left ventricular dysfunction (LV) and high mortality. HF patients are stratified into two groups based on their LV ejection fraction (EF) — HF with normal EF (HFNEF) and with reduced EF (HFREF). EF is a commonly used measure of LV contractile performance. Despite preserved EF, a complex mixture of systolic and diastolic dysfunction and variable degrees of LV remodelling underlying HFNEF poses challenges to diagnose and provide pharmacological treatment for HFNEF. In recent years, the velocity flow mapping (VFM) technique has been developed to generate flow velocity vector fields by post-processing color Doppler echocardiographic (echo) images. We aim to obtain the intra-LV blood flow patterns for patients with HFNEF, HFREF, and normal subjects, in order to characterize the LV performance outcomes of normal subjects and HF patients. Two subjects from each group of HFNEF, HFREF, and normal underwent echo scans. Velocity vector distributions throughout the cardiac cycle were then analysed using the VFM technique. In each subject, the outflow rate during systole, inflow rate during diastole, as well as wall stress-based pressure-normalized contractility index, dσ*/dt max , were computed and compared among the groups. This study demonstrated the use of VFM to visualize LV blood flow patterns in HF patients and normal subjects. Different patterns of flow distributions were observed in these subjects. In HFREF patients, dσ*/dt max , the peak outflow rate and peak inflow rate during early filling were markedly reduced. In HFNEF patients, peak outflow rates were increased compared to those of normal subjects.
Collapse
Affiliation(s)
- THU-THAO LE
- National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore 168752, Singapore
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - RU-SAN TAN
- National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore 168752, Singapore
| | - FEIQIONG HUANG
- National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore 168752, Singapore
| | - LIANG ZHONG
- National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore 168752, Singapore
| | - SRIDHAR IDAPALAPATI
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - DHANJOO GHISTA
- Missouri State University, West Plains, Missouri 65775, USA
| |
Collapse
|
5
|
Guerra M, Sampaio F, Brás-Silva C, Leite-Moreira AF. Left intraventricular diastolic and systolic pressure gradients. Exp Biol Med (Maywood) 2011; 236:1364-72. [DOI: 10.1258/ebm.2011.011134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To describe left ventricular (LV) function comprehensively, it is crucial to characterize precisely transmitral, intraventricular and transaortic pressure–flow relations. The site of measurement is important; as the measurement location is moved from the mitral valve toward the apex and the outflow tract, important regional pressure differences are recorded inside the LV. These intraventricular pressure gradients (IVPGs) play an important role in ventricular filling in the normal heart and may be abolished by systolic or diastolic dysfunction. Despite their apparent importance in ventricular filling and diastolic function, IVPGs have never been utilized in clinical cardiology, due to the complexity of their acquisition. The application of Doppler echocardiography allows the reconstruction of diastolic IVPGs completely non-invasively, thus avoiding the risk and expense of a cardiac catheterization. Regional pressure gradients are also present during ventricular emptying but their correlation with systolic function is not so clear. The current minireview highlights theories and experimental data on invasive and non-invasive assessment of diastolic and systolic IVPGs and their role in LV filling and emptying. We also review the pathophysiological modulation of regional gradients, their importance in understanding and evaluating the complex phenomena underlying ventricular filling, as well as their potential clinical application.
Collapse
Affiliation(s)
- Miguel Guerra
- Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto
- Department of Cardiothoracic Surgery
| | - Francisco Sampaio
- Department of Cardiology, Centro Hospitalar de Vila Nova de Gaia/Espinho, Rua Conceição Fernandes, Vila Nova de Gaia 4434-502
| | - Cármen Brás-Silva
- Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto
- Faculty of Nutrition and Food Sciences, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto
| | - Adelino F Leite-Moreira
- Department of Physiology and Cardiothoracic Surgery, Cardiovascular R&D Unit, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto
- Centre of Thoracic Surgery, Hospital São João, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
| |
Collapse
|
6
|
Bia D, Cabrera-Fischer EI, Zócalo Y, Armentano RL. Intra-aortic balloon pumping reduces the increased arterial load caused by acute cardiac depression, modifying central and peripheral load determinants in a time- and flow-related way. Heart Vessels 2011; 27:517-27. [DOI: 10.1007/s00380-011-0203-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 09/30/2011] [Indexed: 11/24/2022]
|
7
|
A modified elastance model to control mock ventricles in real-time: numerical and experimental validation. ASAIO J 2009; 54:563-73. [PMID: 19033767 DOI: 10.1097/mat.0b013e31818a5c93] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
This article describes an elastance-based mock ventricle able to reproduce the correct ventricular pressure-volume relationship and its correct interaction with the hydraulic circuit connected to it. A real-time control of the mock ventricle was obtained by a new left ventricular mathematical model including resistive and inductive terms added to the classical Suga-Sagawa elastance model throughout the whole cardiac cycle. A valved piston pump was used to mimic the left ventricle. The pressure measured into the pump chamber was fed back into the mathematical model and the calculated reference left ventricular volume was used to drive the piston. Results show that the classical model is very sensitive to pressure disturbances, especially during the filling phase, while the modified model is able to filter out the oscillations thus eliminating their detrimental effects. The presented model is thus suitable to control mock ventricles in real-time, where sudden pressure disturbances represent a key issue and are not negligible. This real-time controlled mock ventricle is able to reproduce the elastance mechanism of a natural ventricle by mimicking its preload (mean atrial pressure) and afterload (mean aortic pressure) sensitivity, i.e., the Starling law. Therefore, it can be used for designing and testing cardiovascular prostheses due to its capability to reproduce the correct ventricle-vascular system interaction.
Collapse
|
8
|
Long Q, Merrifield R, Xu XY, Kilner P, Firmin DN, Yang GZ. Subject-specific computational simulation of left ventricular flow based on magnetic resonance imaging. Proc Inst Mech Eng H 2008; 222:475-85. [DOI: 10.1243/09544119jeim310] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A detailed investigation of left ventricle (LV) flow patterns could improve our understanding of the function of the heart and provide further insight into the mechanisms of heart failure. This study presents patient-specific modelling with magnetic resonance imaging (MRI) to investigate LV blood flow patterns in normal subjects. In the study, the prescribed LV wall movements based on the MRI measurements drove the blood flow in and out of the LV in computational fluid dynamics simulation. For the six subjects studied, the simulated LV flow swirls towards the aortic valve and is ejected into the ascending aorta with a vertical flow pattern that follows the left-hand rule. In diastole, the inflow adopts a reasonably straight route (with no significant secondary flow) towards the apex in the rapid filling phase with slight variations in the jet direction between different cases. When the jet reaches about two thirds of the distance from the inflow plane to the apex, the blood flow starts to change direction and swirls towards the apex. In the more slowly filling phase, a centrally located jet is evident with vortices located on both sides of the jet on an anterior—posterior plane that passes through the mitral and aortic valves. In the inferior—superior plane, a main vortex appears for most of the cases in which an anticlockwise vortex appears for three cases and a clockwise vortex occurs for one case. The simulated flow patterns agree well qualitatively with MRI-measured flow fields.
Collapse
Affiliation(s)
- Q Long
- Brunel Institute for Bioengineering, Brunel University, Uxbridge, UK
| | - R Merrifield
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | - X Y Xu
- Department of Chemical Engineering and Chemical Technology, Imperial College London, London, UK
| | - P Kilner
- Cardiovascular MR Unit, Royal Brompton Hospital, Imperial College London, London, UK
| | - D N Firmin
- Cardiovascular MR Unit, Royal Brompton Hospital, Imperial College London, London, UK
| | - G-Z Yang
- Institute of Biomedical Engineering, Imperial College London, London, UK
| |
Collapse
|
9
|
Zhong L, Ghista DN, Ng EYK, Lim ST, Chua TSJ, Lee CN. Effect of left ventricular shape alteration on contractility and function. J Med Eng Technol 2007; 31:253-62. [PMID: 17566929 DOI: 10.1080/03091900500412692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We have investigated the effect of left ventricular (LV) shape on contractility and ejection function. In this study, a new contractility index is developed in terms of the wall stress (sigma*, normalized with respect to LV pressure) by means of an LV ellipsoidal model. Using cine-ventriculography data, the LV ellipsoidal model (LVEM) major (B) and minor axes (A) are derived for the entire cardiac cycle. Thereafter, a new contractility index (CONT1) is derived as dsigma*/dt, incorporating the LV ellipsoidal shape factor. Also, another contractility index (CONT2) was developed in terms of the generated sigma* at the start of ejection phase, and maximized with respect to B/Ashape parameter, to obtain the optimal value of B/Aover the physiological ranges of the ratio of myocardial volume and LV volume. The in vivovalue of B/Aat the start of ejection is compared with this optimal value, and the LV contractility is evaluated in terms of the proximity of the in vivo B/Ato the optimal B/A. The results indicate that a non-optimal less-ellipsoidal shape (or more spherical) is associated with decreased contractility (and poor systolic function) of the LV, associated with a failing heart.
Collapse
Affiliation(s)
- L Zhong
- School of Mechanical and Production Engineering, College of Engineering, Nanyang Technological University, Nanyang Avenue, Republic of Singapore
| | | | | | | | | | | |
Collapse
|
10
|
Yotti R, Bermejo J, Desco MM, Antoranz JC, Rojo-Alvarez JL, Cortina C, Allué C, Rodríguez-Abella H, Moreno M, García-Fernández MA. Doppler-Derived Ejection Intraventricular Pressure Gradients Provide a Reliable Assessment of Left Ventricular Systolic Chamber Function. Circulation 2005; 112:1771-9. [PMID: 16172285 DOI: 10.1161/circulationaha.104.485128] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Ejection intraventricular pressure gradients are caused by the systolic force developed by the left ventricle (LV). By postprocessing color Doppler M-mode (CDMM) images, we can measure noninvasively the ejection intraventricular pressure difference (EIVPD) between the LV apex and the outflow tract. This study was designed to assess the value of Doppler-derived EIVPDs as noninvasive indices of systolic chamber function. METHODS AND RESULTS CDMM images and pressure-volume (conductance) signals were simultaneously acquired in 9 minipigs undergoing pharmacological interventions and acute ischemia. Inertial, convective, and total EIVPD curves were calculated from CDMM recordings. Peak EIVPD closely correlated with indices of systolic function based on the pressure-volume relationship: peak elastance (within-animal R=0.98; between-animals R=0.99), preload recruitable stroke work (within-animal R=0.81; between-animals R=0.86), and peak of the first derivative of pressure corrected for end-diastolic volume (within-animal R=0.88; between-animals R=0.91). The correlation of peak inertial EIVPD with these indices was also high (all R>0.75). Load dependence of EIVPDs was studied in another 5 animals in which consecutive beats obtained during load manipulation were analyzed. During caval occlusion (40% EDV reduction), dP/dtmax, ejection fraction, and stroke volume significantly changed, whereas peak EIVPD remained constant. Aortic occlusion (40% peak LV pressure increase) significantly modified dP/dtmax, ejection fraction, and stroke volume; a nearly significant trend toward decreasing peak EIVPD was observed (P=0.06), whereas inertial EIVPD was unchanged (P=0.6). EIVPD beat-to-beat and interobserver variabilities were 2+/-12% and 5+/-11%, respectively. CONCLUSIONS Doppler-derived EIVPDs provide quantitative, reproducible, and relatively load-independent indices of global systolic chamber function that correlate closely with currently available reference methods.
Collapse
Affiliation(s)
- Raquel Yotti
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, 28007 Madrid, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
|
12
|
Zhong L, Ghista DN, Ng EYK, Lim ST, Chua TSJ, Lee CN. Left ventricular shape-based contractility index. J Biomech 2005; 39:2397-409. [PMID: 16168419 DOI: 10.1016/j.jbiomech.2005.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Accepted: 08/01/2005] [Indexed: 01/19/2023]
Abstract
This study develops contractility indices in terms of the left ventricular (LV) ellipsoidal geometrical shape-factor. The contractility index (CONT1) is given by the maximum value dsigma(*)/dt wherein sigma(*)=sigma/P, sigma is the wall stress, and sigma(*) is expressed in terms of the shape factor S (the ratio of the minor axis and major axis, B/A, of the instantaneous LV ellipsoidal model). Another contractility index (CONT2) is also developed based on how far apart the in vivo S at the start of ejection is from its optimized value, CONT2=(S(se)-S(se)(op))/S(se)(op), where S(se) refers to the value of S at the start of ejection, S(se)(op) is the derived optimal value of S(se) for which sigma* is maximum. The values of S(=B/A) were calculated from cineventriculographically monitored LV volume, myocardial volume and wall-thickness. Then both the contractility indices were evaluated in normal subjects, as well as in patients with mild heart failure and in patients with severe heart failure. The normal values of CONT1 and CONT2 are 8.75+/-2.30s(-1) and 0.09+/-0.07, respectively. CONT1 decreased in patients with mild and severe heart failures to 5.78+/-1.30 and 3.90+/-1.30, respectively. CONT2 increased in patients with mild and severe heart failures to 0.11+/-0.09 and 0.23+/-0.12, respectively. This implies that a non-optimal and less ellipsoidal shape is associated with decreased contractility (and poor systolic function) of the LV. CONT1 and CONT2 are useful as non-invasively determinable quantitative indices of LV contractility, to distinguish between normal and pathologic LVs.
Collapse
Affiliation(s)
- Liang Zhong
- School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | | | | | | | | | | |
Collapse
|
13
|
Mackerle J. Finite element modelling and simulations in cardiovascular mechanics and cardiology: A bibliography 1993–2004. Comput Methods Biomech Biomed Engin 2005; 8:59-81. [PMID: 16154871 DOI: 10.1080/10255840500141486] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The paper gives a bibliographical review of the finite element modelling and simulations in cardiovascular mechanics and cardiology from the theoretical as well as practical points of views. The bibliography lists references to papers, conference proceedings and theses/dissertations that were published between 1993 and 2004. At the end of this paper, more than 890 references are given dealing with subjects as: Cardiovascular soft tissue modelling; material properties; mechanisms of cardiovascular components; blood flow; artificial components; cardiac diseases examination; surgery; and other topics.
Collapse
Affiliation(s)
- Jaroslav Mackerle
- Department of Mechanical Engineering, Linköping Institute of Technology, Sweden.
| |
Collapse
|
14
|
Yotti R, Bermejo J, Antoranz JC, Rojo-Alvarez JL, Allue C, Silva J, Desco MM, Moreno M, García-Fernández MA. Noninvasive assessment of ejection intraventricular pressure gradients. J Am Coll Cardiol 2004; 43:1654-62. [PMID: 15120827 DOI: 10.1016/j.jacc.2003.09.066] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2003] [Revised: 08/14/2003] [Accepted: 09/29/2003] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The study was designed to validate in vivo a new method to measure ejection intraventricular pressure gradients (IVPGs) by processing color M-mode Doppler data and to assess the effects of inotropic interventions on IVPGs in the clinical setting. BACKGROUND In the absence of obstruction, ejection IVPGs cannot be estimated by Doppler using the simplified Bernoulli equation. METHODS High-fidelity micromanometers were placed in the left ventricle of eight minipigs, and synchronic Doppler images and pressure signals were obtained during different hemodynamic conditions. Twenty healthy volunteers and 20 dilated cardiomyopathy patients were studied at baseline and during esmolol, dobutamine, and atropine infusion (only dobutamine in patients). RESULTS Excellent agreement was observed between micromanometer and Doppler methods for measuring instantaneous pressure differences among the apex, the mid-cavity, and the outflow tract (R(intraclass) = 0.98, 0.81, 0.76, and 0.98 for the peak, time-to-peak, peak reverse, and time-to-peak reverse values, respectively; n = 810 beats). Error of the noninvasive method was -0.05 +/- 0.25 mm Hg for the peak pressure difference. Parametrical images demonstrated that IVPGs originate mainly in the mid-ventricle and then propagate to the outflow tract. Both the magnitude and the temporal course of IVPGs were different among volunteers and patients. Inotropic interventions induced significant changes in the apex-outflow tract pressure differences in both populations, whereas atropine had no effect on IVPGs. CONCLUSIONS For the first time, ejection IVPGs can be accurately visualized and measured by Doppler-echocardiography. Important aspects of the dynamic interaction among myocardial performance, load mechanics, and ejection dynamics can be assessed in the clinical setting using this method.
Collapse
Affiliation(s)
- Raquel Yotti
- Department of Cardiology, Hospital General Universitario Gregorio Marañon, Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
15
|
|
16
|
Bermejo J, Antoranz JC, Yotti R, Moreno M, García-Fernández MA. Spatio-temporal mapping of intracardiac pressure gradients. A solution to Euler's equation from digital postprocessing of color Doppler M-mode echocardiograms. ULTRASOUND IN MEDICINE & BIOLOGY 2001; 27:621-630. [PMID: 11397526 DOI: 10.1016/s0301-5629(01)00349-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Doppler assessment of intracardiac pressure gradients using the simplified Bernoulli equation is inaccurate in the absence of a restricted orifice. The purpose of this study is to develop a new general method to map instantaneous pressure gradients inside the heart using Doppler echocardiography. Color Doppler M-mode recordings are digitally postprocessed with a software algorithm that decodes flow velocity and fits a bivariate spatio-temporal tensor-product smoothing spline. Temporal and spatial accelerations are then calculated by analytical derivation of the fitted velocity data, allowing solution of both inertial and convective terms of Euler's equation. A database of 39 transmitral inflow and transaortic outflow color Doppler M-mode recordings from 20 patients with a number of cardiac conditions was analysed, along with matched pulsed-wave spectral recordings. A close agreement was observed between the spectral and postprocessed color Doppler velocity values (error = 0.8 +/- 11.7 cm/s), validating the data decoding and fitting process. Spatio-temporal pressure-gradient maps were obtained from all studies, allowing visualisation of instantaneous pressure gradients from the atrium to the apex during left ventricular filling, and from the apex to the outflow tract during ejection. Instantaneous pressure differences between localised intracardiac sample points closely matched previously published catheterization findings, both in magnitude and waveform shape. Our method shows that intracardiac instantaneous pressure gradients can be analysed noninvasively using color Doppler M-mode echocardiography combined with image postprocessing methods.
Collapse
Affiliation(s)
- J Bermejo
- Laboratory of Echocardiography, Department of Cardiology, Hospital General Universitario Gregorio Marañón, Universidad Complutense de Madrid, Madrid, Spain.
| | | | | | | | | |
Collapse
|
17
|
Redaelli A, Maisano F, Schreuder JJ, Montevecchi FM. Ventricular motion during the ejection phase: a computational analysis. J Appl Physiol (1985) 2000; 89:314-22. [PMID: 10904067 DOI: 10.1152/jappl.2000.89.1.314] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the present paper, the study of the ventricular motion during systole was addressed by means of a computational model of ventricular ejection. In particular, the implications of ventricular motion on blood acceleration and velocity measurements at the valvular plane (VP) were evaluated. An algorithm was developed to assess the force exchange between the ventricle and the surrounding tissue, i.e., the inflow and outflow vessels of the heart. The algorithm, based on the momentum equation for a transitory flowing system, was used in a fluid-structure model of the ventricle that includes the contractile behavior of the fibers and the viscous and inertial forces of the intraventricular fluid. The model calculates the ventricular center of mass motion, the VP motion, and intraventricular pressure gradients. Results indicate that the motion of the ventricle affects the noninvasive estimation of the transvalvular pressure gradient using Doppler ultrasound. The VP motion can lead to an underestimation equal to 12.4 +/- 6.6%.
Collapse
Affiliation(s)
- A Redaelli
- Department of Bioengineering and Centro di Bioingegneria e Innovazioni Tecnologiche in Cardiochirurgia, Politecnico di Milano, and Instituti di Ricovero e Cura a Carattere Scientifico San Raffaele, 20133 Milan, Italy.
| | | | | | | |
Collapse
|