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Abstract
AIM Evidence on the impact of blood pressure (BP)-lowering drugs on left ventricular (LV) mechanics in hypertension is still limited. We performed a meta-analysis of speckle-tracking echocardiographic studies in order to provide a new piece of information on this topic. METHODS The PubMed, OVID-MEDLINE, and Cochrane library databases were analysed to search for articles published from the inception up to 31 October 2021. Studies were identified by using MeSH terms and crossing the following search items: 'myocardial strain', 'left ventricular mechanics', 'speckle tracking echocardiography', 'systolic dysfunction', 'left ventricular hypertrophy', 'systemic hypertension', 'BP lowering drugs,' 'antihypertensive therapy'. RESULTS A total of 1140 hypertensive patients (mean age 55.4 years, 50% men, follow-up 6-36 months) were included in eight studies. Pretreatment and posttreatment pooled SBP/DBPs were 148.4 ± 3.5/88.7 ± 2 vs. 127.4 ± 1.9/77.8 ± 0.9 mmHg. Corresponding values for ejection fraction (EF), LV mass (LVM) index, and global longitudinal strain (GLS) were 64 ± 2.3 vs. 65.9 ± 1.7% (SMD: 0.14 ± 0.03, CI 0.08- 0.20, P = 0.001); 108.4 ± 11.2 vs. 100.2 ± 11.0 g/m2 (SMD: -0.27 ± 0.10, CI -0.46 to -0.08, P < 0.01); -17.7 ± 0.6 vs. -19.6 ± 0.4%, (SMD 0.26 ± 0.03, CI 0.20-0.32, P < 0.0001), respectively. A meta-regression analysis showed a significant relation between GLS improvement and the extent of reduction of LVMI (P = 0.0003), but not of SBP (P = 0.27). CONCLUSION Our meta-analysis suggests that antihypertensive treatment has a clear beneficial effect on LV mechanisms, and the improvement in GLS is mainly related to the reduction in LVMI rather than SBP.
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Samaee M, Nelsen NH, Gaddam MG, Santhanakrishnan A. Diastolic Vortex Alterations With Reducing Left Ventricular Volume: An In Vitro Study. J Biomech Eng 2020; 142:121006. [PMID: 32601698 DOI: 10.1115/1.4047663] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Indexed: 07/25/2024]
Abstract
Despite the large number of studies of intraventricular filling dynamics for potential clinical applications, little is known as to how the diastolic vortex ring properties are altered with reduction in internal volume of the cardiac left ventricle (LV). The latter is of particular importance in LV diastolic dysfunction (LVDD) and in congenital diseases such as hypertrophic cardiomyopathy (HCM), where LV hypertrophy (LVH) can reduce LV internal volume. We hypothesized that peak circulation and the rate of decay of circulation of the diastolic vortex would be altered with reducing end diastolic volume (EDV) due to increasing confinement. We tested this hypothesis on physical models of normal LV and HCM geometries, under identical prescribed inflow profiles and for multiple EDVs, using time-resolved particle image velocimetry (TR-PIV) measurements on a left heart simulator. Formation and pinch-off of the vortex ring were nearly unaffected with changes to geometry and EDV. Pinch-off occurred before the end of early filling (E-wave) in all test conditions. Peak circulation of the vortex core near the LV outflow tract (LVOT) increased with lowering EDV and was lowest for the HCM model. The rate of decay of normalized circulation in dimensionless formation time (T*) increased with decreasing EDV. When using a modified version of T* that included average LV cross-sectional area and EDV, normalized circulation of all tested EDVs collapsed closely in the normal LV model (10% maximum difference between EDVs). Collectively, our results show that LV shape and internal volume play a critical role in diastolic vortex ring dynamics.
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Affiliation(s)
- Milad Samaee
- School of Mechanical and Aerospace Engineering, Oklahoma State University, 201 General Academic Building, Stillwater, OK 74078
| | - Nicholas H Nelsen
- School of Mechanical and Aerospace Engineering, Oklahoma State University, 201 General Academic Building, Stillwater, OK 74078
| | - Manikantam G Gaddam
- School of Mechanical and Aerospace Engineering, Oklahoma State University, 201 General Academic Building, Stillwater, OK 74078
| | - Arvind Santhanakrishnan
- School of Mechanical and Aerospace Engineering, Oklahoma State University, 201 General Academic Building, Stillwater, OK 74078
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The Effect of Dobutamine Stress Testing on Vortex Formation Time in Patients Evaluated for Ischemia. J Cardiovasc Transl Res 2020; 14:735-743. [DOI: 10.1007/s12265-020-09998-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 03/25/2020] [Indexed: 02/06/2023]
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4
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Universality of vortex ring decay in the left ventricle. J Biomech 2020; 103:109695. [DOI: 10.1016/j.jbiomech.2020.109695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 02/08/2020] [Accepted: 02/21/2020] [Indexed: 11/18/2022]
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Is mitral annular ascent useful in studying left ventricular function through left atrio-ventricular interactions? Indian Heart J 2018; 70:368-372. [PMID: 29961452 PMCID: PMC6034026 DOI: 10.1016/j.ihj.2017.08.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 08/13/2017] [Accepted: 08/22/2017] [Indexed: 12/03/2022] Open
Abstract
Background The mitral annulus (MA) is a crucial structure that is in constant motion throughout the cardiac cycle. The main purpose of this study was to determine if M-mode evaluation of the longitudinal motion of the MA could be useful to examine atrio-ventricular interactions. Methods Echocardiographic data obtained from 150 patients (mean age 56 ± 16; 82 males) from the University of Cincinnati College of Medicine was evaluated to examine if any relationship exists between MA motion and measures of atrio-ventricular interactions. Results Even though left atrial size, left ventricular (LV) mass index, LV ejection fraction (LVEF) and degree of LV diastolic dysfunction (LVDD) were significant echocardiographic variables affecting MA motion; LVEF and the degree of LVDD were the main determinants of MA excursion during systole (MAPSE) and after atrial contraction (MAa). Our results confirm the surrogate value of MAPSE with regards to LVEF and also show that the extent of MA excursion during systole is the main determinant of MAa. The effect of LV diastolic function applies more strongly to MAPSE than to MAa. However, the maximal MAa amplitude varies in accordance to the type of LVDD. Conclusions We have shown for the first time that M-mode interrogation of the MA longitudinal motion appears useful to assess atrio-ventricular interactions. Since LV systolic and diastolic functions are so closely related; additional studies are now required to examine how this longitudinal measure correlates with known circumferential rotational data obtained with other imaging modalities.
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Lopez-Candales A, Hernandez-Suarez DF, Menendez FL. Are Measures of Left Ventricular Longitudinal Shortening Affected by Left Atrial Enlargement? Cardiol Res 2018; 9:1-6. [PMID: 29479378 PMCID: PMC5819621 DOI: 10.14740/cr637w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 11/30/2017] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Even though left atrial (LA) size and function are intimately related to left ventricular (LV) diastolic dysfunction, the role of LA with regard to LV systolic function is less clear. Consequently, we examined the potential association that might exist between measures of longitudinal LV systolic shortening and LA dilation using LA volume index (LAVI). METHODS In this retrospective analysis, data from 75 echocardiograms (mean age 53 ± 14; range 24 - 89 years; mean body surface area (BSA) 2.0 ± 0.3) were analyzed. RESULTS Peak global longitudinal (PGLS) correlated best with LV mass index (LVMI) followed by mitral annular systolic excursion (MAPSE), and age. Similar results were obtained when analyzing the best variables that correlated with LAVI. Finally, MAPSE correlated best with PGLS, then with MA tissue Doppler systolic velocity, BSA, and LAVI in that order. All patients had normal LV ejection fraction (LVEF) and normal sinus rhythm when studied. CONCLUSIONS LAVI does not directly affect LV systolic function and longitudinal measures of LV shortening are mainly dependent on LV mass. Additional studies are now required to determine how these associations vary when different degrees of LV dilatation and systolic dysfunction are included in the analysis.
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Affiliation(s)
- Angel Lopez-Candales
- Cardiovascular Medicine Division, School of Medicine, University of Puerto Rico, San Juan, Puerto Rico
| | | | - Francisco Lopez Menendez
- Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Zhou BY, Xie MX, Wang J, Wang XF, Lv Q, Liu MW, Kong SS, Zhang PY, Liu JF. Relationship between the abnormal diastolic vortex structure and impaired left ventricle filling in patients with hyperthyroidism. Medicine (Baltimore) 2017; 96:e6711. [PMID: 28445281 PMCID: PMC5413246 DOI: 10.1097/md.0000000000006711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Intraventricular hydrodynamics plays an important role in evaluating cardiac function. Relationship between diastolic vortex and left ventricular (LV) filling is still rarely elucidated. The aim of this study was to evaluate the evolution of vortex during diastole in hyperthyroidism (HT) and explore the alteration of hydromechanics characteristics with sensitive indexes.Forty-three patients diagnosed with HT were classified into 2 groups according to whether myocardial damage existed: simple hyperthyroid group (HT1, n = 21) and thyrotoxic cardiomyopathy (HT2, n = 22). Twenty-seven age- and gender-matched healthy volunteers were enrolled as the control group. Offline vector flow mapping (VFM model) was used to analyze the LV diastolic blood flow patterns and fluid dynamics. Hemodynamic parameters, vortex area (A), circulation (C), and intraventricular pressure gradient (ΔP), in different diastolic phases (early, mid, and late) were calculated and analyzed.HT2, with a lower E/A ratio and left ventricular ejection fraction (LVEF), had a larger left atrium diameter (LAD) compared with those of the control group and HT1 (P < .05). Compared with the control group, the vortex size and strength, intraventricular pressure gradient during early and mid-diastole were higher in HT1 and lower in HT2 (P < .05). And in late diastole, the vortex size and strength, intraventricular pressure gradient of HT2 became higher than those of the control group (P < .05). Good correlation could be found between CE and E/A (P < .05), CM and ΔPM (P < .01), CL and FT3 (P < .05).VFM is proven practical for detecting the relationship between the changes of left ventricular diastolic vortex and the abnormal left ventricular filling.
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Affiliation(s)
- Bin-Yu Zhou
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
- Department of Ultrasound, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, China
| | - Ming-Xing Xie
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Jing Wang
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Xin-Fang Wang
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Qing Lv
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Man-Wei Liu
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Shuang-Shuang Kong
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Ping-Yu Zhang
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
| | - Jin-Feng Liu
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan
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Kamphuis VP, Westenberg JJM, van der Palen RLF, Blom NA, de Roos A, van der Geest R, Elbaz MSM, Roest AAW. Unravelling cardiovascular disease using four dimensional flow cardiovascular magnetic resonance. Int J Cardiovasc Imaging 2016; 33:1069-1081. [PMID: 27888419 PMCID: PMC5489572 DOI: 10.1007/s10554-016-1031-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/21/2016] [Indexed: 11/29/2022]
Abstract
Knowledge of normal and abnormal flow patterns in the human cardiovascular system increases our understanding of normal physiology and may help unravel the complex pathophysiological mechanisms leading to cardiovascular disease. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has emerged as a suitable technique that enables visualization of in vivo blood flow patterns and quantification of parameters that could potentially be of prognostic value in the disease process. In this review, current image processing tools that are used for comprehensive visualization and quantification of blood flow and energy distribution in the heart and great vessels will be discussed. Also, imaging biomarkers extracted from 4D flow CMR will be reviewed that have been shown to distinguish between normal and abnormal flow patterns. Furthermore, current applications of 4D flow CMR in the heart and great vessels will be discussed, showing its potential as an additional diagnostic modality which could aid in disease management and timing of surgical intervention.
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Affiliation(s)
- Vivian P Kamphuis
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands
| | - Jos J M Westenberg
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Roel L F van der Palen
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Nico A Blom
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - Albert de Roos
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rob van der Geest
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mohammed S M Elbaz
- Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Arno A W Roest
- Division of Pediatric Cardiology, Department of Pediatrics, Leiden University Medical Center, Leiden, The Netherlands
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9
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Irizarry Pagán EE, Vargas PE, López-Candales A. The clinical dilemma of heart failure with preserved ejection fraction: an update on pathophysiology and management for physicians. Postgrad Med J 2016; 92:346-55. [DOI: 10.1136/postgradmedj-2015-133859] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/11/2016] [Indexed: 12/20/2022]
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Lai CQ, Lim GL, Jamil M, Mattar CNZ, Biswas A, Yap CH. Fluid mechanics of blood flow in human fetal left ventricles based on patient-specific 4D ultrasound scans. Biomech Model Mechanobiol 2015; 15:1159-72. [DOI: 10.1007/s10237-015-0750-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Accepted: 12/01/2015] [Indexed: 11/28/2022]
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Elbaz MSM, Calkoen EE, Westenberg JJM, Lelieveldt BPF, Roest AAW, van der Geest RJ. Vortex flow during early and late left ventricular filling in normal subjects: quantitative characterization using retrospectively-gated 4D flow cardiovascular magnetic resonance and three-dimensional vortex core analysis. J Cardiovasc Magn Reson 2014; 16:78. [PMID: 25270083 PMCID: PMC4177574 DOI: 10.1186/s12968-014-0078-9] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 09/01/2014] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND LV diastolic vortex formation has been suggested to critically contribute to efficient blood pumping function, while altered vortex formation has been associated with LV pathologies. Therefore, quantitative characterization of vortex flow might provide a novel objective tool for evaluating LV function. The objectives of this study were 1) assess feasibility of vortex flow analysis during both early and late diastolic filling in vivo in normal subjects using 4D Flow cardiovascular magnetic resonance (CMR) with retrospective cardiac gating and 3D vortex core analysis 2) establish normal quantitative parameters characterizing 3D LV vortex flow during both early and late ventricular filling in normal subjects. METHODS With full ethical approval, twenty-four healthy volunteers (mean age: 20±10 years) underwent whole-heart 4D Flow CMR. The Lambda2-method was used to extract 3D LV vortex ring cores from the blood flow velocity field during early (E) and late (A) diastolic filling. The 3D location of the center of vortex ring core was characterized using cylindrical cardiac coordinates (Circumferential, Longitudinal (L), Radial (R)). Comparison between E and A filling was done with a paired T-test. The orientation of the vortex ring core was measured and the ring shape was quantified by the circularity index (CI). Finally, the Spearman's correlation between the shapes of mitral inflow pattern and formed vortex ring cores was tested. RESULTS Distinct E- and A-vortex ring cores were observed with centers of A-vortex rings significantly closer to the mitral valve annulus (E-vortex L=0.19±0.04 versus A-vortex L=0.15±0.05; p=0.0001), closer to the ventricle's long-axis (E-vortex: R=0.27±0.07, A-vortex: R=0.20±0.09, p=0.048) and more elliptical in shape (E-vortex: CI=0.79±0.09, A-vortex: CI=0.57±0.06; <0.001) compared to E-vortex. The circumferential location and orientation relative to LV long-axis for both E- and A-vortex ring cores were similar. Good to strong correlation was found between vortex shape and mitral inflow shape through both the annulus (r=0.66) and leaflet tips (r=0.83). CONCLUSIONS Quantitative characterization and comparison of 3D vortex rings in LV inflow during both early and late diastolic phases is feasible in normal subjects using retrospectively-gated 4D Flow CMR, with distinct differences between early and late diastolic vortex rings.
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Affiliation(s)
- Mohammed S M Elbaz
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, C3-Q room 54, Albinusdreef 2, Leiden, 2333 ZA The Netherlands
| | - Emmeline E Calkoen
- />Department of Paediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jos J M Westenberg
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, C3-Q room 54, Albinusdreef 2, Leiden, 2333 ZA The Netherlands
| | - Boudewijn P F Lelieveldt
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, C3-Q room 54, Albinusdreef 2, Leiden, 2333 ZA The Netherlands
- />Department of Intelligent Systems, Delft University of Technology, Delft, The Netherlands
| | - Arno A W Roest
- />Department of Paediatric Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rob J van der Geest
- />Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, C3-Q room 54, Albinusdreef 2, Leiden, 2333 ZA The Netherlands
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Ghosh E, Kovács SJ. The vortex formation time to diastolic function relation: assessment of pseudonormalized versus normal filling. Physiol Rep 2013; 1:e00170. [PMID: 24400169 PMCID: PMC3871482 DOI: 10.1002/phy2.170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 10/30/2013] [Accepted: 11/01/2013] [Indexed: 01/18/2023] Open
Abstract
In early diastole, the suction pump feature of the left ventricle opens the mitral valve and aspirates atrial blood. The ventricle fills via a blunt profiled cylindrical jet of blood that forms an asymmetric toroidal vortex ring inside the ventricle whose growth has been quantified by the standard (dimensionless) expression for vortex formation time, VFTstandard = {transmitral velocity time integral}/{mitral orifice diameter}. It can differentiate between hearts having distinguishable early transmitral (Doppler E-wave) filling patterns. An alternative validated expression, VFTkinematic reexpresses VFTstandard by incorporating left heart, near “constant-volume pump” physiology thereby revealing VFTkinematic's explicit dependence on maximum rate of longitudinal chamber expansion (E′). In this work, we show that VFTkinematic can differentiate between hearts having indistinguishable E-wave patterns, such as pseudonormal (PN; 0.75 < E/A < 1.5 and E/E′ > 8) versus normal. Thirteen age-matched normal and 12 PN data sets (738 total cardiac cycles), all having normal LVEF, were selected from our Cardiovascular Biophysics Laboratory database. Doppler E-, lateral annular E′-waves, and M-mode data (mitral leaflet separation, chamber dimension) was used to compute VFTstandard and VFTkinematic. VFTstandard did not differentiate between groups (normal [3.58 ± 1.06] vs. PN [4.18 ± 0.79], P = 0.13). In comparison, VFTkinematic for normal (3.15 ± 1.28) versus PN (4.75 ± 1.35) yielded P = 0.006. Hence, the applicability of VFTkinematic for diastolic function quantitation has been broadened to include analysis of PN filling patterns in age-matched groups.
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Affiliation(s)
- Erina Ghosh
- Department of Biomedical Engineering, School of Engineering and Applied Science, Washington University in St Louis St. Louis, Missouri
| | - Sándor J Kovács
- Department of Biomedical Engineering, School of Engineering and Applied Science, Washington University in St Louis St. Louis, Missouri ; Cardiovascular Biophysics Laboratory, Cardiovascular Division, Department of Internal Medicine, School of Medicine, Washington University in St Louis St. Louis, Missouri
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López-Candales A. Automated Functional Imaging for Assessment of Left Ventricular Mechanics in the Presence of Left Ventricular Hypertrophy. Echocardiography 2013; 31:605-14. [DOI: 10.1111/echo.12441] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Angel López-Candales
- Division of Cardiovascular Diseases; University of Cincinnati College of Medicine; Cincinnati Ohio
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Pagel PS, Hudetz JA. Chronic pressure-overload hypertrophy attenuates vortex formation time in patients with severe aortic stenosis and preserved left ventricular systolic function undergoing aortic valve replacement. J Cardiothorac Vasc Anesth 2013; 27:660-4. [PMID: 23727466 DOI: 10.1053/j.jvca.2013.01.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Indexed: 01/19/2023]
Abstract
OBJECTIVE Transmitral blood flow produces a vortex ring that enhances the hydraulic efficiency of early left ventricular (LV) filling. The effect of pressure-overload hypertrophy on the duration of LV vortex ring formation (vortex formation time [VFT]) is unknown. The current investigation tested the hypothesis that chronic LV pressure-overload hypertrophy produced by severe aortic stenosis (AS) reduces VFT in patients with preserved LV systolic function undergoing aortic valve replacement. DESIGN Observational study. SETTING Veterans Affairs Medical Center. PARTICIPANTS After the Institutional Review Board's approval, 8 patients (7 men and 1 woman; age, 62±5 y; and ejection fraction, 59%±5%) with AS (peak pressure gradient, 81±22 mmHg; aortic valve area, 0.78±0.25 cm(2)) scheduled for aortic valve replacement were compared with 8 patients (all men; age, 63±3 y; and ejection fraction, 60%±7%) without AS undergoing coronary artery bypass graft surgery. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Under general anesthesia, peak early LV filling (E) and atrial systole (A) blood flow velocities and their corresponding velocity-time integrals were obtained using pulse-wave Doppler echocardiography to determine E/A and atrial filling fraction (β). Mitral valve diameter (D) was calculated as the average of minor and major axis lengths obtained in the midesophageal bicommissural and long-axis transesophageal echocardiography imaging planes, respectively. Posterior wall thickness (PWT) was measured at end-diastole using M-mode echocardiography. VFT was calculated as 4×(1-β)×SV/πD(3), where SV = stroke volume measured using thermodilution. Systemic and pulmonary hemodynamics, LV diastolic function, PWT, and VFT were determined during steady-state conditions 30 minutes before cardiopulmonary bypass. Early LV filling was attenuated in patients with AS (eg, E/A, 0.77±0.11 compared with 1.23±0.13; β, 0.43±0.09 compared with 0.35±0.02; p<0.05 for each). LV hypertrophy was observed (PWT, 1.4±0.1 cm compared with 1.1±0.2 cm; p<0.05) and VFT was lower (3.0±0.9 v 4.3±0.5; p<0.05) in patients with versus without AS. Linear regression analysis showed a significant correlation between VFT and PWT (VFT = -2.57 ×PWT + 6.81; r(2) = 0.345; p = 0.017). CONCLUSION The results indicated that pressure-overload hypertrophy produced by AS reduced VFT in patients with normal LV systolic function undergoing aortic valve replacement.
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Affiliation(s)
- Paul S Pagel
- Anesthesia Service, Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, WI 53295, USA.
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Ghosh E, Kovács SJ. Early Left Ventricular Diastolic Function Quantitation Using Directional Impedances. Ann Biomed Eng 2013; 41:1269-78. [DOI: 10.1007/s10439-013-0756-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 01/23/2013] [Indexed: 11/25/2022]
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Stewart KC, Charonko JC, Niebel CL, Little WC, Vlachos PP. Left ventricular vortex formation is unaffected by diastolic impairment. Am J Physiol Heart Circ Physiol 2012; 303:H1255-62. [PMID: 22961866 DOI: 10.1152/ajpheart.00093.2012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Normal left ventricular (LV) filling occurs rapidly early in diastole caused by a progressive pressure gradient within the ventricle and with a low left atrial pressure. This normal diastolic function is altered in patients with heart failure. Such impairment of diastolic filling is manifested as an abrupt deceleration of the early filling wave velocity. Although variations within the early filling wave have been observed previously, the underlying hydrodynamic mechanisms are not well understood. Previously, it was proposed that the mitral annulus vortex ring formation time was the total duration of early diastolic filling and provided a measure of the efficiency of diastolic filling. However, we found that the favorable LV pressure difference driving early diastolic filling becomes zero simultaneously with the deceleration of the early filling wave propagation velocity and pinch-off of the LV vortex ring. Thus we calculated the vortex ring formation time using the duration of the early diastolic filling wave from its initiation to the time of the early filling wave propagation velocity deceleration when pinch-off occurs. This formation time does not vary with decreasing intraventricular pressure difference or with degree of diastolic dysfunction. Thus we conclude the vortex ring pinch-off occurs before the completion of early diastole, and its formation time remains invariant to changes of diastolic function.
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Affiliation(s)
- Kelley C Stewart
- Department of Mechanical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
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Le TB, Sotiropoulos F. On the three-dimensional vortical structure of early diastolic flow in a patient-specific left ventricle. EUROPEAN JOURNAL OF MECHANICS. B, FLUIDS 2012; 35:20-24. [PMID: 22773898 PMCID: PMC3388554 DOI: 10.1016/j.euromechflu.2012.01.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We study the formation of the mitral vortex ring during early diastolic filling in a patient-specific left ventricle using direct numerical simulation. The geometry of the left ventricle is reconstructed from Magnetic Resonance Imaging (MRI). The heart wall motion is modeled by a cell-based activation methodology, which yields physiologic kinematics with heart rate equal to 52 beats per minute. We show that the structure of the mitral vortex ring consists of the main vortex ring and trailing vortex tubes, which originate at the heart wall. The trailing vortex tubes play an important role in exciting twisting circumferential instability modes of the mitral vortex ring. At the end of diastole, the vortex ring impinges on the wall and the intraventricular flow transitions to a weak turbulent state. Our results can be used to help interprete and analyze three-dimensional in-vivo flow measurements obtained with MRI.
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Affiliation(s)
- Trung Bao Le
- St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Fotis Sotiropoulos
- St. Anthony Falls Laboratory, Department of Civil Engineering, University of Minnesota, Minneapolis, MN, USA
- Corresponding author at: Saint Anthony Falls Lab., Dept. Civil Engineering, University of Minnesota, 2 Third Ave SE, Minneapolis, MN 55414. Tel: +1 612 624 2022
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Töger J, Kanski M, Carlsson M, Kovács SJ, Söderlind G, Arheden H, Heiberg E. Vortex ring formation in the left ventricle of the heart: analysis by 4D flow MRI and Lagrangian coherent structures. Ann Biomed Eng 2012; 40:2652-62. [PMID: 22805980 DOI: 10.1007/s10439-012-0615-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 06/28/2012] [Indexed: 10/28/2022]
Abstract
Recent studies suggest that vortex ring formation during left ventricular (LV) rapid filling is an optimized mechanism for blood transport, and that the volume of the vortex ring is an important measure. However, due to lack of quantitative methods, the volume of the vortex ring has not previously been studied. Lagrangian Coherent Structures (LCS) is a new flow analysis method, which enables in vivo quantification of vortex ring volume. Therefore, we aimed to investigate if vortex ring volume in the human LV can be reliably quantified using LCS and magnetic resonance velocity mapping (4D PC-MR). Flow velocities were measured using 4D PC-MR in 9 healthy volunteers and 4 patients with dilated ischemic cardiomyopathy. LV LCS were computed from flow velocities and manually delineated in all subjects. Vortex volume in the healthy volunteers was 51 ± 6% of the LV volume, and 21 ± 5% in the patients. Interobserver variability was -1 ± 13% and interstudy variability was -2 ± 12%. Compared to idealized flow experiments, the vortex rings showed additional complexity and asymmetry, related to endocardial trabeculation and papillary muscles. In conclusion, LCS and 4D PC-MR enables measurement of vortex ring volume during rapid filling of the LV.
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Affiliation(s)
- Johannes Töger
- Department of Clinical Physiology, Skåne University Hospital Lund, Lund University, 221 85, Lund, Sweden
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Pagel PS, Gandhi SD, Iqbal Z, Hudetz JA. Cardiopulmonary Bypass Transiently Inhibits Intraventricular Vortex Ring Formation in Patients Undergoing Coronary Artery Bypass Graft Surgery. J Cardiothorac Vasc Anesth 2012; 26:376-80. [DOI: 10.1053/j.jvca.2011.10.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Indexed: 11/11/2022]
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Assessment of Transmitral Vortex Formation in Patients with Diastolic Dysfunction. J Am Soc Echocardiogr 2012; 25:220-7. [DOI: 10.1016/j.echo.2011.10.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Indexed: 11/19/2022]
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