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Marchese P, Cantinotti M, Van den Eynde J, Assanta N, Franchi E, Pak V, Santoro G, Koestenberger M, Kutty S. Left ventricular vortex analysis by high-frame rate blood speckle tracking echocardiography in healthy children and in congenital heart disease. IJC HEART & VASCULATURE 2021; 37:100897. [PMID: 34786451 PMCID: PMC8579140 DOI: 10.1016/j.ijcha.2021.100897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/29/2022]
Abstract
Background High-frame rate blood speckle tracking (BST) echocardiography is a new technique for the assessment of intracardiac flow. The purpose of this study was to evaluate the characteristics of left ventricular (LV) vortices in healthy children and in those with congenital heart disease (CHD). Methods Characteristics of LV vortices were analyses based on 4-chamber BST images from 118 healthy children (median age 6.84 years, range 0.01-17 years) and 43 children with CHD (median age 0.99 years, range 0.01-14 years). Both groups were compared after propensity matching. Multiple linear regression was used to identify factors that independently influence vortex characteristics. Results Feasibility of vortex imaging was 93.7% for healthy children and 95.6% for CHD. After propensity matching, there were no overall significant differences in vortex distance to apex, distance to interventricular septum (IVS), height, width, sphericity index, or area. However, multiple regression analysis revealed significant associations of LV morphology with vortex characteristics. Furthermore, CHD involving LV volume overload and CHD involving LV pressure overload were both associated with vortices localized closer to the IVS. Conclusions LV vortex analysis using high-frame rate BST echocardiography is feasible in healthy children and in those with CHD. As they are associated with LV morphology and are modified in some types of CHD, vortices might yield diagnostic and prognostic value. Future studies are warranted to establish applications of vortex imaging in the clinical setting.
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Key Words
- -i, indexed to BSA
- AV, atrioventricular
- BMI, body mass index
- BSA, body surface area
- BST, blood speckle tracking
- Blood speckle imaging
- Bpm, beats per minute
- CHD, congenital heart disease
- CI, correlation index
- Congenital
- ED, end-diastolic
- Echocardiography
- Fps, frame per second
- Heart defects
- ICC, intraclass correlation coefficient
- IQR, interquartile range
- IVS, interventricular septum
- LV, left ventricle/ventricular
- LVEDA, left ventricular end-diastolic area
- LVEDD, left ventricular end-diastolic dimension
- LVEDV, left ventricular end-diastolic volume
- LVEF, left ventricular ejection fraction
- LVESD, left ventricular end-systolic dimension
- LVESV, left ventricular end-systolic volume
- LVOT, left ventricular outflow tract
- LVPO, CHD involving left ventricle pressure overload
- LVSV, left ventricular stroke volume
- LVVO, CHD involving left ventricular volume overload
- Left ventricle
- MV, mitral valve
- Pediatrics
- RVPO, CHD involving right ventricular pressure overload
- RVVO, CHD involving right ventricular volume overload
- TGA, transposition of the great arteries
- Vortex imaging
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Affiliation(s)
- Pietro Marchese
- Fondazione G. Monasterio CNR-Regione Toscana, Massa and Pisa, Italy.,Adult Institute of Clinical Physiology, Pisa, Italy
| | | | - Jef Van den Eynde
- Taussig Heart Center, Department of Pediatrics, Johns Hopkins Hospital, Baltimore, MD, USA.,Department of Cardiovascular Sciences, KU Leuven, Leuven, Belgium
| | - Nadia Assanta
- Fondazione G. Monasterio CNR-Regione Toscana, Massa and Pisa, Italy
| | - Eliana Franchi
- Fondazione G. Monasterio CNR-Regione Toscana, Massa and Pisa, Italy
| | - Vitali Pak
- Fondazione G. Monasterio CNR-Regione Toscana, Massa and Pisa, Italy
| | - Giuseppe Santoro
- Fondazione G. Monasterio CNR-Regione Toscana, Massa and Pisa, Italy
| | | | - Shelby Kutty
- Taussig Heart Center, Department of Pediatrics, Johns Hopkins Hospital, Baltimore, MD, USA
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Cesarovic N, Weisskopf M, Kron M, Glaus L, Peper ES, Buoso S, Suendermann S, Canic M, Falk V, Kozerke S, Emmert MY, Stoeck CT. Septaly Oriented Mild Aortic Regurgitant Jets Negatively Influence Left Ventricular Blood Flow-Insights From 4D Flow MRI Animal Study. Front Cardiovasc Med 2021; 8:711099. [PMID: 34434980 PMCID: PMC8380779 DOI: 10.3389/fcvm.2021.711099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/06/2021] [Indexed: 11/23/2022] Open
Abstract
Objectives: Paravalvular leakage (PVL) and eccentric aortic regurgitation remain a major clinical concern in patients receiving transcatheter aortic valve replacement (TAVR), and regurgitant volume remains the main readout parameter in clinical assessment. In this work we investigate the effect of jet origin and trajectory of mild aortic regurgitation on left ventricular hemodynamics in a porcine model. Methods: A pig model of mild aortic regurgitation/PVL was established by transcatheter piercing and dilating the non-coronary (NCC) or right coronary cusp (RCC) of the aortic valve close to the valve annulus. The interaction between regurgitant blood and LV hemodynamics was assessed by 4D flow cardiovascular MRI. Results: Six RCC, six NCC, and two control animals were included in the study and with one dropout in the NCC group, the success rate of model creation was 93%. Regurgitant jets originating from NCC were directed along the ventricular side of the anterior mitral leaflet and integrated well into the diastolic vortex forming in the left ventricular outflow tract. However, jets from the RCC were orientated along the septum colliding with flow within the vortex, and progressing down to the apex. As a consequence, the presence as well as the area of the vortex was reduced at the site of impact compared to the NCC group. Impairment of vortex formation was localized to the area of impact and not the entire vortex ring. Blood from the NCC jet was largely ejected during the following systole, whereas ejection of large portion of RCC blood was protracted. Conclusions: Even for mild regurgitation, origin and trajectory of the regurgitant jet does cause a different effect on LV hemodynamics. Septaly oriented jets originating from RCC collide with the diastolic vortex, reduce its size, and reach the apical region of the left ventricle where blood resides extendedly. Hence, RCC jets display hemodynamic features which may have a potential negative impact on the long-term burden to the heart.
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Affiliation(s)
- Nikola Cesarovic
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland.,Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Miriam Weisskopf
- Division of Surgical Research, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Mareike Kron
- Division of Surgical Research, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Lukas Glaus
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Eva S Peper
- Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland
| | - Stefano Buoso
- Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland
| | - Simon Suendermann
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,Department of Cardiovascular Surgery, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Marko Canic
- Division of Surgical Research, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Volkmar Falk
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology, Zurich, Switzerland.,Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,Department of Cardiovascular Surgery, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland
| | - Maximilian Y Emmert
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,Department of Cardiovascular Surgery, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Christian T Stoeck
- Institute for Biomedical Engineering, University and ETH Zürich, Zurich, Switzerland
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Kasoju VT, Santhanakrishnan A. Pausing after clap reduces power required to fling wings apart at low Reynolds number. BIOINSPIRATION & BIOMIMETICS 2021; 16:056006. [PMID: 34034247 DOI: 10.1088/1748-3190/ac050a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 05/25/2021] [Indexed: 06/12/2023]
Abstract
The smallest flying insects, such as thrips (body length < 2 mm), are challenged with needing to move in air at a chord-based Reynolds number (Rec) of the order of 10. Pronounced viscous dissipation at such a low Recrequires considerable energetic expenditure for tiny insects to stay aloft. Thrips flap their densely bristled wings at large stroke amplitudes, bringing both wings in close proximity to each other at the end of upstroke ('clap') and moving their wings apart at the start of downstroke ('fling'). From high-speed videos of free take-off flights of thrips, we observed that their forewings remain clapped for approximately 10% of the wingbeat cycle before the start of downstroke (fling stroke). We sought to examine if there are aerodynamic advantages associated with pausing wing motion after upstroke (clap stroke) and before downstroke (fling stroke) at Rec= 10. A dynamically scaled robotic clap and fling platform was used to measure lift and drag forces generated by physical models of solid (non-bristled) and bristled wings in single wing and wing pair configurations, for pause times ranging between 0% to 41% of the cycle. For solid and bristled wing pairs, pausing before the start of downstroke (fling stroke) dissipated vorticity generated at the end of upstroke (clap stroke). This resulted in a decrease in the drag coefficient averaged across downstroke (fling stroke) and in turn reduced power requirements. Also, increasing the pause time resulted in a larger decrease in the dimensionless power coefficient for the wing-pair configurations compared to the single-wing configurations. Our findings show that wing-wing interaction observed in the clap and fling motion of tiny insect wings is necessary to realize the aerodynamic benefits of pausing before fling, by reducing the power required to clap and fling for a small compromise in lift.
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Affiliation(s)
- Vishwa T Kasoju
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, United States of America
| | - Arvind Santhanakrishnan
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078, United States of America
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Kasoju VT, Moen DS, Ford MP, Ngo TT, Santhanakrishnan A. Interspecific variation in bristle number on forewings of tiny insects does not influence clap-and-fling aerodynamics. J Exp Biol 2021; 224:272163. [PMID: 34286832 DOI: 10.1242/jeb.239798] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 07/19/2021] [Indexed: 11/20/2022]
Abstract
Miniature insects must overcome significant viscous resistance in order to fly. They typically possess wings with long bristles on the fringes and use clap-and-fling mechanism to augment lift. These unique solutions to the extreme conditions of flight at tiny sizes (< 2 mm body length) suggest that natural selection has optimized wing design for better aerodynamic performance. However, species vary in wingspan, number of bristles (n), and bristle gap (G) to diameter (D) ratio (G/D). How this variation relates to body length (BL) and its effects on aerodynamics remain unknown. We measured forewing images of 38 species of thrips and 21 species of fairyflies. Our phylogenetic comparative analyses showed that n and wingspan scaled positively and similarly with body length across both groups, whereas G/D decreased with BL, with a sharper decline in thrips. We next measured aerodynamic forces and visualized flow on physical models of bristled wings performing clap-and-fling kinematics at chord-based Reynolds number of 10 using a dynamically scaled robotic platform. We examined the effects of dimensional (G, D, wingspan) and non-dimensional (n, G/D) geometric variables on dimensionless lift and drag. We found that: (a) increasing G reduced drag more than decreasing D; (b) changing n had minimal impact on lift generation; and (c) varying G/D minimally affected aerodynamic forces. These aerodynamic results suggest little pressure to functionally optimize n and G/D. Combined with the scaling relationships between wing variables and BL, much wing variation in tiny flying insects might be best explained by underlying shared growth factors.
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Affiliation(s)
- Vishwa T Kasoju
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078-5016, USA
| | - Daniel S Moen
- Department of Integrative Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Mitchell P Ford
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078-5016, USA
| | - Truc T Ngo
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078-5016, USA
| | - Arvind Santhanakrishnan
- School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078-5016, USA
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