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Lee J, El Hangouche N, Pathrose A, Soulat G, Barker AJ, Thomas JD, Markl M. Bicuspid aortic valve morphology and hemodynamics by same-day echocardiography and cardiac MRI. THE INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING 2022; 38:2047-2056. [PMID: 35294708 DOI: 10.1007/s10554-022-02593-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 03/07/2022] [Indexed: 11/28/2022]
Abstract
This study investigated the impact of bicuspid aortic valve (BAV) on valve morphology and motion as well as proximal and aortic hemodynamics using a same-day echocardiography and cardiac MRI. Transthoracic echocardiography, two-dimensional cine MRI of the aortic valve, and aortic 4D flow MRI were performed on the same day in 9 normofunctional BAV patients (age = 41 ± 12, 3 female), 4 BAV with moderate to severe aortic stenosis (AS) (age = 63 ± 5, 1 female), and 36 healthy tricuspid aortic valve controls (age = 52 ± 10, 21 female). Valve opening and closing timings and transvalvular peak velocity were measured using B-mode and Doppler echocardiogram, respectively. Valve orifice morphology at a fully-opened state was characterized using cine MRI. Ascending aortic (AAo) wall shear stress (WSS) was measured using 4D flow MRI data. Valve motion timings were similar between BAV and controls. BAV was associated with an increased orifice aspect ratio (1.44 ± 0.11 vs. 1.10 ± 0.13, P < 0.001), transvalvular peak velocity (1.5 ± 0.3 vs. 1.2 ± 0.2 m/s, P < 0.001) and maximum AAo WSS (1.62 ± 0.31 vs. 0.91 ± 0.24 Pa, P < 0.001). The increased orifice aspect ratio was associated with the increase in transvalvular peak velocity (r = 0.80, P < 0.0001) and maximum AAo WSS (r = 0.83, P < 0.0001). Transvalvular peak velocity was also positively correlated with maximum AAo WSS (r = 0.83, P < 0.0001). A same-day echo and MRI imaging allows for a comprehensive assessment of the impact of aortic valve disease on valve function and hemodynamics. In this pilot application to BAV, we found increased orifice aspect ratio may be responsible for increased transvalvular peak velocity and maximum AAo WSS.
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Affiliation(s)
- Jeesoo Lee
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL, 60611, USA.
| | - Nadia El Hangouche
- Department of Cardiology, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Ashitha Pathrose
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL, 60611, USA
| | - Gilles Soulat
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL, 60611, USA
| | - Alex J Barker
- Department of Radiology, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - James D Thomas
- Department of Cardiology, Northwestern Memorial Hospital, Chicago, IL, 60611, USA
| | - Michael Markl
- Department of Radiology, Feinberg School of Medicine, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL, 60611, USA
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, 60208, USA
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Saisho H, Scharfschwerdt M, Schaller T, Sadat N, Aboud A, Ensminger S, Fujita B. Ex vivo evaluation of the Ozaki procedure in comparison with the native aortic valve and prosthetic valves. Interact Cardiovasc Thorac Surg 2022; 35:6650697. [PMID: 35895002 PMCID: PMC9443990 DOI: 10.1093/icvts/ivac199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/14/2022] [Accepted: 07/26/2022] [Indexed: 11/19/2022] Open
Affiliation(s)
- Hiroyuki Saisho
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
| | - Michael Scharfschwerdt
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
| | - Tim Schaller
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
| | - Najla Sadat
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
- DZHK (German Centre for Cardiovascular Research—Partner Site Hamburg/Kiel/Lübeck) , Germany
| | - Anas Aboud
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
| | - Stephan Ensminger
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
- DZHK (German Centre for Cardiovascular Research—Partner Site Hamburg/Kiel/Lübeck) , Germany
| | - Buntaro Fujita
- Department of Cardiac and Thoracic Vascular Surgery, University Hospital of Schleswig Holstein , Lübeck, Germany
- University of Lübeck , Lübeck, Germany
- DZHK (German Centre for Cardiovascular Research—Partner Site Hamburg/Kiel/Lübeck) , Germany
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3
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Kaya M, Balasubramanian V, Li JKJ. Inadequacy of Augmentation Index for Monitoring Arterial Stiffness: Comparison with Arterial Compliance and Other Hemodynamic Variables. Cardiovasc Eng Technol 2022; 13:590-602. [PMID: 35102522 DOI: 10.1007/s13239-021-00605-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 12/14/2021] [Indexed: 01/09/2023]
Abstract
PURPOSE Augmentation Index (AIx) is used clinically for monitoring both wave reflections and arterial stiffness, which when increased is a risk factor of cardiovascular mortality and morbidity. We hypothesize that AIx is not solely related to vascular stiffness as described by arterial compliance and other hemodynamic parameters since AIx underestimates wave reflections. METHODS Aortic pressure and flow datasets (n = 42) from mongrel dogs were obtained from our experiments and Mendeley Data under various conditions. Arterial compliances based on the Windkessel model (Ct), the stroke volume (SV) to pulse pressure (PP) ratio (Cv = SV/PP), and at inflection pressure point (CPi) were computed. Other relevant hemodynamic factors are also computed. RESULTS AIx was poorly associated with arterial stiffness calculated from Ct (r = 0.299, p = 0.058) or CPi (r = 0.203, p = 0.203), even when adjusted for heart rates. Ct and Cv were monotonically associated. Alterations in inflection pressure (Pi) did not follow the changes in pulse pressure (PP) (r = 0.475, p = 0.002), and Pi was quantitatively similar to systolic pressure (r = 0.940, p < 0.001). CONCLUSION AIx is neither linearly correlated with arterial stiffness, nor with arterial compliance and several cardiac and arterial parameters have to be considered when AIx is calculated.
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Affiliation(s)
- Mehmet Kaya
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150 W University Blvd, Melbourne, FL, 32901, USA.
| | - Vignesh Balasubramanian
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 150 W University Blvd, Melbourne, FL, 32901, USA
| | - John K-J Li
- Department of Biomedical Engineering and Robert Wood Johnson Medical School, Rutgers University, 599 Taylor Road, Piscataway, NJ, 08854, USA
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Tasca G, Jaworek M, Lucherini F, Trinca F, Redaelli P, Antona C, Vismara R. Leaflet kinematics after the Yacoub and Florida-sleeve operations: results of an in vitro study. Eur J Cardiothorac Surg 2021; 59:674-679. [PMID: 33236049 DOI: 10.1093/ejcts/ezaa370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 08/14/2020] [Accepted: 09/05/2020] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES The Florida-sleeve is a valve-sparing technique that causes minimal interference to leaflet kinematics and aortic root dynamism. The aim of this in vitro study was to evaluate the effects of the Florida-sleeve and Yacoub techniques on aortic leaflet kinematics. METHODS Two groups of 6 whole porcine hearts were treated with either the Florida-sleeve technique or the Yacoub technique and tested in a pulsatile loop. Valve fluid dynamics, coronary flow analysis and valve echocardiograms were performed both before and after the procedures. RESULTS Both procedures showed no difference in rapid valve opening time as compared with their respective baseline values. The Florida-sleeve procedure showed a shorter slow closing time (192 ± 19 ms vs baseline 244 ± 14 ms, P = 0.016) and increased slow closing velocity (-1.5 ± 0.4 cm/s vs baseline -0.8 ± 0.4 cm/s, P = 0.038). In the rapid valve closing phase, the Yacoub procedure showed a trend towards slower closing valve velocity (-16 ± 9 cm/s vs baseline -25 ± 9 cm/s, P = 0.07). The Yacoub procedure showed larger leaflet displacement at the end of the slow valve closing time that was 2.0 ± 0.5 cm vs baseline 1.5 ± 0.3 cm, P = 0.044. When comparing the Florida-sleeve and Yacoub procedures, the former showed statistically significant shorter slow valve closing time (P = 0.017). CONCLUSIONS This study showed that the Florida-sleeve technique alters the slow closing phase of the aortic valve leaflet kinematics when compared with both the normal baseline and Yacoub procedure, while the latter showed a larger leaflet displacement before the rapid closing valve phase.
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Affiliation(s)
- Giordano Tasca
- Department of Cardiac Surgery, Heart Health Center, King Saud Medical City, Riyadh, Kingdom of Saudi Arabia.,Department of Electronic, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Michal Jaworek
- Department of Electronic, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Federico Lucherini
- Department of Electronic, Information and Bioengineering, Politecnico di Milano, Milan, Italy
| | - Francesco Trinca
- Cardiovascular Department, Operative Unit of Cardiac Surgery, Spedali Civili di Brescia, Brescia, Italy
| | - Paola Redaelli
- Cardiovascular Department, Cardiac Surgery Unit, San Raffaele Hospital, Milan, Italy
| | - Carlo Antona
- Cardiovascular Surgery Department, ASST Fatebenefratelli "Luigi Sacco" University Hospital, Milan, Italy
| | - Riccardo Vismara
- Department of Electronic, Information and Bioengineering, Politecnico di Milano, Milan, Italy
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Zhong Z, Sun K, Dan G, Luo Q, Farzaneh-Far A, Karaman MM, Zhou XJ. Visualization of Human Aortic Valve Dynamics Using Magnetic Resonance Imaging with Sub-Millisecond Temporal Resolution. J Magn Reson Imaging 2021; 54:1246-1254. [PMID: 33761166 DOI: 10.1002/jmri.27603] [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: 11/11/2020] [Revised: 03/03/2021] [Accepted: 03/05/2021] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Visualization of aortic valve dynamics is important in diagnosing valvular diseases but is challenging to perform with magnetic resonance imaging (MRI) due to the limited temporal resolution. PURPOSE To develop an MRI technique with sub-millisecond temporal resolution and demonstrate its application in visualizing rapid aortic valve opening and closing in human subjects in comparison with echocardiography and conventional MRI techniques. STUDY TYPE Prospective. POPULATION Twelve healthy subjects. FIELD STRENGTH/SEQUENCE 3 T; gradient-echo-train-based sub-millisecond periodic event encoded imaging (get-SPEEDI) and balanced steady-state free precession (bSSFP). ASSESSMENT Images were acquired using get-SPEEDI with a temporal resolution of 0.6 msec. get-SPEEDI was triggered by an electrocardiogram so that each echo in the gradient echo train corresponded to an image at a specific time point, providing a time-resolved characterization of aortic valve dynamics. For comparison, bSSFP was also employed with 12 msec and 24 msec temporal resolutions, respectively. The durations of the aortic valve rapid opening (Tro ), rapid closing (Trc ), and the maximal aortic valve area (AVA) normalized to height were measured with all three temporal resolutions. M-mode echocardiograms with a temporal resolution of 0.8 msec were obtained for further comparison. STATISTICAL TEST Parameters were compared between the three sequences, together with the echocardiography results, with a Mann-Whitney U test. RESULTS Significantly shorter Tro (mean ± SD: 27.5 ± 6.7 msec) and Trc (43.8 ± 11.6 msec) and larger maximal AVA/height (2.01 ± 0.29 cm2 /m) were measured with get-SPEEDI compared to either bSSFP sequence (Tro of 56.3 ± 18.8 and 63.8 ± 20.2 msec; Trc of 68.2 ± 16.6 and 72.8 ± 18.2 msec; maximal AVA/height of 1.63 ± 0.28 and 1.65 ± 0.32 cm2 /m for 12 msec and 24 msec temporal resolutions, respectively, P < 0.05). In addition, the get-SPEEDI results were more consistent with those measured using echocardiography, especially for Tro (29.0 ± 4.1 msec, P = 0.79) and Trc (41.6 ± 4.3 msec, P = 0.16). DATA CONCLUSION: get-SPEEDI allows for visualization of human aortic valve dynamics and provided values closer to those measured using echocardiography than the bSSFP sequences. LEVEL OF EVIDENCE 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Zheng Zhong
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Kaibao Sun
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Guangyu Dan
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Qingfei Luo
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Afshin Farzaneh-Far
- Department of Radiology, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Meryem Muge Karaman
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Xiaohong Joe Zhou
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Radiology, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA
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Nishida K, Yokoi Y, Yamada A, Takaya N, Yamagiwa K, Kawada S, Mori K, Manabe S, Kanda E, Fujioka T, Kishino M, Tateishi U. Optimal phase analysis of electrocardiogram-gated computed tomography angiography in patients with Stanford type A acute aortic dissection. Eur J Radiol Open 2020; 7:100289. [PMID: 33318968 PMCID: PMC7726336 DOI: 10.1016/j.ejro.2020.100289] [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: 11/12/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 10/27/2022] Open
Abstract
Objective To determine the phase that facilitates flap observation of the ascending aorta in Stanford type A acute aortic dissection with perfused false lumen. Methods We reconstructed retrospective Electrocardiogram-gated Computed Tomography Angiography images of the ascending aorta of all 20 patients to 20 phases of curved-multiplanar reconstruction in 5% increment. One radiologist created and randomized 10 cross-sectional images of each phase for every patient and two radiologists scored these images on a 5-point scale depending on the degree of flap stoppage. We calculated the average score for each phase of each case and compared them among the three groups. Results Image scores were significantly better in the 65 %-100 % R-R interval group than those in the 5%-30 % (p < 2e-16) and 35 %-60 % R-R interval groups(p = 7.2e-10). Similar scores were observed in the Heart Rate > 70 group (p = 0.00039, 2.2e-14). Moreover a similar tendency was observed in the arrhythmia group (p = 0.0035, 0.294). No difference was found in the degree of flap stoppage in the 65 %-100 % R-R interval group between the Heart Rate > 70 and Heart Rate ≤ 70 groups (p = 0.466) and between the arrhythmia and non-arrhythmia groups (p = 0.1240). Conclusion In observing the ascending aorta, We obtained a good image at 65 %-100 % R-R interval and similar tendency was observed in the patients with arrhythmia.
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Key Words
- AAD, acute aortic dissection
- AC, atrial contraction phase
- AEC, automatic exposure control
- AR, Aortic Regurgitation
- Aorta thoracic
- CTA, computed tomography angiography
- Computed tomography angiography
- D, diastolic phase
- DLP, dose-length-product
- Dissecting
- E, effective dose
- ECG, electrocardiogram
- Electrocardiography
- HR, heart rate
- IVR, isovolumetric relaxation phase
- MPR, multiplanar reconstruction
- RF, rapid filling phase
- RR, R-R interval
- Radiation dose
- S, systolic phase
- SF, slow filling phase
- bpm, beats per minute
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Affiliation(s)
- Kenji Nishida
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan.,Department of Diagnostic Radiology and Nuclear Medicine, Graduate School of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Yuki Yokoi
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Ayumi Yamada
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Nobuhiro Takaya
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Ken Yamagiwa
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Shuichi Kawada
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Koichi Mori
- Department of Diagnostic Radiology, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Susumu Manabe
- Department of Cardiovascular Surgery, Tsuchiura Kyodo General Hospital, 4-1-1 Otsuno, Tsuchiura, Ibaraki, Japan
| | - Eiichiro Kanda
- Department of Nephrology, Kawasaki Medical School Hospital, 577 Matsushima, Kurashiki, Okayama, Japan
| | - Tomoyuki Fujioka
- Department of Diagnostic Radiology and Nuclear Medicine, Graduate School of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Mitsuhiro Kishino
- Department of Diagnostic Radiology and Nuclear Medicine, Graduate School of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
| | - Ukihide Tateishi
- Department of Diagnostic Radiology and Nuclear Medicine, Graduate School of Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-0034, Japan
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Augmentation index in the assessment of wave reflections and systolic loading. Comput Biol Med 2019; 113:103418. [PMID: 31493580 DOI: 10.1016/j.compbiomed.2019.103418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND Augmentation index (AIx) is used to quantify the augmented systolic aortic pressure that impedes ventricular ejection. Its use as an index of wave reflections is questionable. We hypothesize that AIx is quantitatively different from the reflection coefficient under varied physiological conditions. METHODS 42 datasets of aortic pressure and flow waveforms were obtained during induced hypertension (methoxamine infusion) and vasodilation (nitroprusside infusion) in our mongrel dog experiments (n = 5) and from Mendeley data during various interventions (vasoconstrictors, vasodilators, pacing, stimulation, hemorrhage and hemodilution). Wave reflections and principal components of reflection coefficients were computed for comparison to AIx and heart rate normalized AIx. RESULTS: Principal reflection coefficient, Γ1, increased in hypertension and decreased in vasodilation, hemorrhage and hemodilution. AIx followed the trend in many cases but was consistently lower than Γ1 in almost all the subjects. The Bland-Altman analysis also showed that both AIx and normalized AIx underestimated Γ1. The relationship between augmentation index and reflection coefficient was explained by a linear regression model (r2 = 0.23, p < 0.01) in which AIx followed directional changes in Γ1 and the normalization of AIx resulted in a linear model that explained less variation in the relationship between AIx and Γ1. CONCLUSION AIx is a reasonable clinical trend indicator, albeit not an accurate surrogate measure of the amount of wave reflections.
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8
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De Paulis R, Salica A. Surgical anatomy of the aortic valve and root-implications for valve repair. Ann Cardiothorac Surg 2019; 8:313-321. [PMID: 31240175 DOI: 10.21037/acs.2019.04.16] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The aortic root is an important anatomical structure positioned at the center of the heart, making it critical to the functioning of the major cardiac chambers. Deep knowledge of the anatomical "surroundings" of the aortic root is crucial for surgeon attempting to spare or repair a leaking aortic valve. In fact, root dissection is a necessary step to "skeletonize" the aortic valve, allowing the surgeon to work on the critical components of its structure, namely the aorto-ventricular junction, the virtual basal ring (VBR) and the sino-tubular junction (STJ). These three components, along with the insertion of the leaflet to the aortic wall, form the skeleton of the aortic valve that is essential in guaranteeing valve competence. A good anatomical proportion between the various component of the skeleton of the aortic valve need to be verified, or re-established in order to set the basis for an optimal aortic valve repair. Once the skeleton of the heart has been correctly addressed, the condition of the valve leaflets need to be considered. Excess of leaflet tissue is treated by leaflet plication or resection and lack of leaflet tissue is addressed by tissue extension with autologous or heterologous materials. In the present manuscript, we highlight the principal structure of the aortic root and describe in detail each anatomical component. This basic anatomical knowledge is also important for a through understanding of the normal function of the valve and root structure during the cardiac cycle. The close boundaries existing between the left ventricular cavity and the aorta are important in explaining the sophisticated function of opening and closing of the aortic valve. Similarly, the role played by the sinuses of Valsalva in regulating the blood flow exiting the ventricle underline the concept that "form follows function" and emphasizes the importance of a good anatomical reconstruction for an optimal and long-lasting valve function.
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Affiliation(s)
| | - Andrea Salica
- Department of Cardiac Surgery, European Hospital, Rome, Italy
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Lansac E, Lim HS, Shomura Y, Lim KH, Rice NT, Di Centa I, Youssefi P, Goetz W, Duran CMG. Aortic valve opening and closure: the clover dynamics. Ann Cardiothorac Surg 2019; 8:351-361. [PMID: 31240179 DOI: 10.21037/acs.2019.05.03] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Systolic aortic root expansion is reported to facilitate valve opening, but the precise dynamics remain unknown. A sonometric study with a high data sampling rate (200 to 800 Hz) was conducted in an acute ovine model to better understand the timing, mechanisms, and shape of aortic valve opening and closure. Methods Eighteen piezoelectric crystals were implanted in 8 sheep at each annular base, commissures, sinus of Valsalva, sinotubular junction, nodulus of Arantius, and ascending aorta (AA). Geometric changes were time related to pressures and flows. Results The aortic root was hemodynamically divided into left ventricular (LV) and aortic compartments situated, respectively, below and above the leaflets. During isovolumetric contraction (IVC), aortic root expansion started in the LV compartment, most likely due to volume redistribution in the LV outflow tract below the leaflets. This expansion initiated leaflet separation prior to ejection (2.1%±0.5% of total opening area). Aortic compartment expansion was delayed toward the end of IVC, likely related to volume redistribution above the leaflets due to accelerating aortic backflow toward the aortic valve and coronary flow reduction due to myocardial contraction. Maximum valve opening during the first third of ejection acquired a truncated cone shape [leaflet free edge area smaller than annular base area (-41.5%±5.5%)]. The distal orifice became clover shaped because the leaflet free edge area is larger than the commissural area by 16.3%±2.0%. Conclusions Aortic valve opening is initiated prior to ejection related to delicate balance between LV, aortic root, and coronary dynamics. It is clover shaped at maximum opening in systole. A better understanding of these mechanisms should stimulate more physiological surgical approaches of valve repair and replacement.
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Affiliation(s)
- Emmanuel Lansac
- Department of Cardiovascular Surgery, Institut Mutualiste Montsouris, Paris, France
| | - Hou-Sen Lim
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Yu Shomura
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Khee Hiang Lim
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Nolan T Rice
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Isabelle Di Centa
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Pouya Youssefi
- Department of Cardiovascular Surgery, Institut Mutualiste Montsouris, Paris, France.,Hospital Foch, Suresnes, France
| | - Wolfgang Goetz
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
| | - Carlos M G Duran
- The International Heart Institute of Montana Foundation at St. Patrick Hospital and Health Sciences Center and The University of Montana, Missoula, Montana, USA
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10
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Aortic root dynamism, geometry, and function after the remodeling operation: Clinical relevance. J Thorac Cardiovasc Surg 2018; 156:951-962.e2. [DOI: 10.1016/j.jtcvs.2018.03.157] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 02/11/2018] [Accepted: 03/06/2018] [Indexed: 01/09/2023]
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11
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Kim IC, Chang S, Hong GR, Lee SH, Lee S, Ha JW, Chang BC, Kim YJ, Shim CY. Comparison of Cardiac Computed Tomography With Transesophageal Echocardiography for Identifying Vegetation and Intracardiac Complications in Patients With Infective Endocarditis in the Era of 3-Dimensional Images. Circ Cardiovasc Imaging 2018; 11:e006986. [DOI: 10.1161/circimaging.117.006986] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 01/26/2018] [Indexed: 02/06/2023]
Affiliation(s)
- In-Cheol Kim
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Suyon Chang
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Geu-Ru Hong
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Seung Hyun Lee
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Sak Lee
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Jong-Won Ha
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Byung-Chul Chang
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Young Jin Kim
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
| | - Chi Young Shim
- From the Division of Cardiology, Severance Cardiovascular Hospital (I.-C.K., G.-R.H., J.-W.H., C.Y.S.), Department of Cardiovascular Surgery, Severance Cardiovascular Hospital (S.H.L., S.L., B.-C.C.), and Department of Radiology, Research Institute of Radiological Science, Severance Hospital (S.C., Y.J.K.), Yonsei University College of Medicine; and Division of Cardiology, Department of Internal Medicine, Dongsan Medical Center, Keimyung University (I.-C.K.)
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Mohammadi H, Cartier R, Mongrain R. 3D physiological model of the aortic valve incorporating small coronary arteries. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2017; 33:e2829. [PMID: 27591390 DOI: 10.1002/cnm.2829] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 07/04/2016] [Accepted: 08/26/2016] [Indexed: 06/06/2023]
Abstract
The diseases of the coronary arteries and the aortic root are still the leading causes of mortality and morbidity worldwide. In this study, a 3D global fluid-structure interaction of the aortic root with inclusion of anatomically inspired small coronary arteries using the finite element method is presented. This innovative model allows to study the impact and interaction of root biomechanics on coronary hemodynamics and brings a new understanding to small coronary vessels hemodynamics. For the first time, the velocity profiles and shear stresses are reported in distal coronary arteries as a result of the aortic flow conditions in a global fluid-structure interaction model.
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Affiliation(s)
- Hossein Mohammadi
- Mechanical Engineering Department, McGill University, Montreal, Quebec, H3A 0C3, Canada
| | - Raymond Cartier
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, Quebec, H1T 1C8, Canada
| | - Rosaire Mongrain
- Mechanical Engineering Department, McGill University, Montreal, Quebec, H3A 0C3, Canada
- Department of Cardiovascular Surgery, Montreal Heart Institute, Montreal, Quebec, H1T 1C8, Canada
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13
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The dicrotic notch analyzed by a numerical model. Comput Biol Med 2016; 72:54-64. [PMID: 27016670 DOI: 10.1016/j.compbiomed.2016.03.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/16/2016] [Accepted: 03/13/2016] [Indexed: 10/22/2022]
Abstract
Divergent concepts on the origin of the dicrotic notch are widespread in medical literature and education. Since most medical textbooks explain the origin of the dicrotic notch as caused by the aortic valve closure itself, this is commonly transmitted in medical physiology courses. We present clinical data and numerical simulations to demonstrate that reflected pressure waves could participate as one of the causes of the dicrotic notch. Our experimental data from continuous arterial pressure measurements from adult patients undergoing vascular surgery suggest that isolated changes in peripheral vascular resistance using an intravenous bolus of phenylephrine (a selective alpha 1-receptor agonist and thus a potent vasoconstrictor) modify the dicrotic notch. We then explore the mechanisms behind this phenomenon by using a numerical model based on integrated axisymmetric Navier-Stokes equations to compute the hemodynamic flow. Our model illustrates clearly how modifications in peripheral artery resistance may result in changes in the amplitude of the dicrotic notch by modifying reflected pressure waves. We believe that this could be a useful tool in teaching medical physiology courses.
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Aboelkassem Y, Savic D, Campbell SG. Modeling predicts a connection between sinus vortex effects and aortic compliance. J Theor Biol 2016; 389:306-9. [DOI: 10.1016/j.jtbi.2015.10.037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Revised: 10/24/2015] [Accepted: 10/28/2015] [Indexed: 10/22/2022]
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15
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Salica A, Pisani G, Morbiducci U, Scaffa R, Massai D, Audenino A, Weltert L, Guerrieri Wolf L, De Paulis R. The combined role of sinuses of Valsalva and flow pulsatility improves energy loss of the aortic valve. Eur J Cardiothorac Surg 2015; 49:1222-7. [PMID: 26362428 DOI: 10.1093/ejcts/ezv311] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/20/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Normal aortic valve opening and closing movement is a complex mechanism mainly regulated by the blood flow characteristics and the cyclic modifications of the aortic root. Our previous in vitro observations demonstrated that the presence of the Valsalva sinuses, independently from root compliance, is important in reducing systolic pressure drop across the aortic valve. This in vitro study was designed to ascertain if this effect is dependent on the flow characteristics. METHODS Stentless 21, 23 and 25 mm aortic prostheses were sutured inside Dacron graft with and without sinuses. Hydrodynamic performance of the root models was investigated in steady-state (continuous) and unsteady-state (pulsatile) flow regimes. Aortic transvalvular pressure drop and effective orifice area (EOA) were evaluated. RESULTS The continuous flow analysis revealed that no marked differences in pressure drop characterized the two root configurations at flow regimes lower than 15 l/min, independently of valve size. Conversely, at higher flow regimes (up to 30 l/min) a relatively low pressure drop continued to characterize grafts with sinuses, whereas marked increments in pressure drop were measured in straight grafts, especially in the smaller size (77.05 ± 4.58 vs 23.80 ± 2.44 mmHg; 18.40 ± 1.31 vs 7.66 ± 0.37 mmHg and 29.54 ± 0.17 vs 7.12 ± 0.07 mmHg, for 21, 23 and 25 mm valve, respectively). Under pulsatile conditions, the presence of sinuses clearly confirmed lower pressure drops also more evident in the smaller valve sizes (53.89 ± 1.06 vs 11.6 ± 0.24 mmHg at 7 l/min for 21 mm valve). EOA values were always lower in the absence of sinuses. In continuous flow regimes, at 30 l/min EOA of 25 mm valve size was 3.67 ± 0.02 cm(2) in the Valsalva model versus 1.79 ± 0.01 cm(2) for the Straight model. In pulsatile tests, at 7 l/min a 25-valve size demonstrated an EOA of 5.47 ± 0.60 in the Valsalva model versus 2.50 ± 0.02 cm(2) in the Straight model. CONCLUSIONS These findings (i) confirm the hypothesis that the sinuses of Valsalva play a key role in optimizing the aortic haemodynamics during systole, minimizing energy losses; (ii) suggest that the sinuses of Valsalva are needed because of the complex nature of blood flow during ejection.
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Affiliation(s)
- Andrea Salica
- Division of Cardiac Surgery, European Hospital, Rome, Italy
| | - Giuseppe Pisani
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Umberto Morbiducci
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | | | - Diana Massai
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Alberto Audenino
- Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Luca Weltert
- Division of Cardiac Surgery, European Hospital, Rome, Italy
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Del Río Palma J, Romero V. E, Cerrolaza M. ANALYSIS OF BLOOD FLOW PASSING THROUGH AORTIC AND MITRAL VALVES USING A COMPUTATIONAL MODEL OF CONCENTRATED PARAMETERS. BIOMEDICAL ENGINEERING: APPLICATIONS, BASIS AND COMMUNICATIONS 2014. [DOI: 10.4015/s1016237214500689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Blood flow has been extensively studied because of its close relationship with cardiovascular disease. Heart valves blood flow analysis is particularly complex due to the high mobility of its leaflets, a fact that has stimulated the development of computational models aimed to its better understanding. For studying heart valves blood flow, we developed a mathematical model derived from clinical observations based on echocardiographic images, which describe valve leaflets motion and its influence on blood flow. This work presents a concentrated-parameters-based model of heart valves blood flow that takes into consideration five main factors affecting such a flow in the mitral and aortic valves. This model considers factors that are related to blood fluid and valve leaflets characteristics. Considering the main factors involved, it was found that blood flow exhibit an abnormal behavior in response to small variations (less than 10%) in blood pressure gradient or in leaflets stiffness. Likewise, after changing the roughness of the leaflets, the impact is smaller, only slightly affecting blood flow behavior with changes beyond 30%. Moreover, it was observed that the influence of fluid vortices originated behind the valves can be disregarded and the kinetic energy induced by them is almost negligible.
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Affiliation(s)
- J. Del Río Palma
- National Institute of Bioengineering, Central University of Venezuela, Venezuela
| | - E. Romero V.
- National Institute of Bioengineering, Central University of Venezuela, Venezuela
- Cardiovascular Studies Lab, "JM Vargas" School of Medicine, Central University of Venezuela, Venezuela
| | - M. Cerrolaza
- National Institute of Bioengineering, Central University of Venezuela, Venezuela
- International Center for Numerical Methods in Engineering (CIMNE), Polytechnic University of Catalonia, Spain
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De Paulis R, Salica A, Pisani G, Morbiducci U, Weltert L, Maselli D. Hemodynamics of the aortic valve and root: implications for surgery. Ann Cardiothorac Surg 2013; 2:40-3. [PMID: 23977557 DOI: 10.3978/j.issn.2225-319x.2012.11.16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 11/30/2012] [Indexed: 11/14/2022]
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Tsang W, Veronesi F, Sugeng L, Weinert L, Takeuchi M, Jeevanandam V, Lang RM. Mitral Valve Dynamics in Severe Aortic Stenosis before and after Aortic Valve Replacement. J Am Soc Echocardiogr 2013; 26:606-14. [DOI: 10.1016/j.echo.2013.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Indexed: 10/27/2022]
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20
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Tsang W, Meineri M, Hahn RT, Veronesi F, Shah AP, Osten M, Nathan S, Russo M, Lang RM, Horlick EM. A three-dimensional echocardiographic study on aortic-mitral coupling in transcatheter aortic valve replacement. Eur Heart J Cardiovasc Imaging 2013; 14:950-6. [PMID: 23720379 DOI: 10.1093/ehjci/jet058] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Normal aortic valve (AV) and mitral valve (MV) function in a reciprocal interdependent fashion. We hypothesized that MV function would be affected by severe aortic stenosis (AS) and that it would remain altered after transcatheter AV replacement (TAVR). Using three-dimensional (3D) echocardiography, we studied aortic-mitral coupling in patients with severe AS undergoing TAVR and compared them with controls. METHODS AND RESULTS Three-dimensional transoesophageal echocardiography (Philips iE33) was performed on 43 patients: 27 with severe AS studied pre- and post-TAVR and 16 controls. A custom software tracked the aortic annulus (AoA) and mitral annulus (MA), allowing dynamic automated measurements of AoA and MA morphology, angle, and motion. The AS pre-TAVR patients had significantly reduced MA displacement, MA area, and maximum AoA area compared with the controls. Post-TAVR, MA displacement, MA area, and AoA area remained reduced. End-systolic AoA-MA angle was significantly wider in the AS patients compared with the controls and remained wider post-TAVR. Pre-TAVR, there was no difference in MA or AoA dynamics between patients with mild vs. moderate-to-severe MA calcium; Edwards-Sapien vs. a Medtronic CoreValve valve; normal vs. reduced left ventricular systolic function whereas post-TAVR, MA dynamics were significantly reduced in those with moderate-to-severe MA calcium. CONCLUSION This is the first study to demonstrate that AS can affect a secondary 'unaffected' valve, the MV, due to the calcification in the aortic-mitral fibrous continuity. TAVR does not result in recovery of MV structure. These changes have implications in the future TAVR valve development and the possible need for MV assessment pre- and post-TAVR.
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Affiliation(s)
- Wendy Tsang
- University of Chicago Medical Center, 5841 South Maryland Avenue, MC 5084, Chicago, IL 60637, USA
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Nobari S, Mongrain R, Leask R, Cartier R. The effect of aortic wall and aortic leaflet stiffening on coronary hemodynamic: a fluid-structure interaction study. Med Biol Eng Comput 2013; 51:923-36. [PMID: 23549924 DOI: 10.1007/s11517-013-1066-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Accepted: 03/16/2013] [Indexed: 12/22/2022]
Abstract
Pathologies of the aortic valve such as aortic sclerosis are thought to impact coronary blood flow. Recent clinical investigations have observed simultaneous structural and hemodynamic variations in the aortic valve and coronary arteries due to regional pathologies of the aortic valve. The goal of the present study is to elucidate this observed and yet unexplained phenomenon, in which a local pathology in the aortic valve region could potentially lead to the initiation or progression of coronary artery disease. Results revealed a considerable impact on the coronary flow, velocity profile, and consequently shear stress due to an increase in the aortic wall or aortic leaflet stiffness and thickness which concur with clinical observations. The cutoff value of 0.75 for fractional flow reserve was reached when the values of leaflet thickness and aortic wall stiffness were approximately twice and three times their normal value, respectively. Variations observed in coronary velocity profiles as well as wall shear stress suggest a possible link for the initiation of coronary artery disease.
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Affiliation(s)
- S Nobari
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada.
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Chang SA, Kim HK, Sohn DW. Impact of afterload on the assessment of severity of aortic stenosis. J Cardiovasc Ultrasound 2012; 20:79-84. [PMID: 22787524 PMCID: PMC3391632 DOI: 10.4250/jcu.2012.20.2.79] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 05/08/2012] [Accepted: 05/15/2012] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Aortic stenosis (AS) is increasingly diagnosed in current aging society. Echocardiography is the most important tool in the assessment of AS and its severity. However, load-dependency of Doppler measurement could affect the accuracy of AS severity assessment. We tried to evaluate the impact of afterload on the assessment of AS severity by modification of afterload using pneumatic compression (Pcom). METHODS Forty patients diagnosed as moderate or severe AS [effective orifice area of aortic valve (EOAAV) by continuity equation of < 1.5 cm2] were consecutively enrolled. Patients with severely uncontrolled hypertension, severe left ventricular (LV) dysfunction, and other significant valve disease were excluded. Comprehensive echocardiography was performed at baseline to assess AS severity. Then, pneumatic compression of the lower extremities by 100 mmHg was applied to increase LV afterload. After 3 minutes, echocardiography was repeated to assess AS severity. RESULTS Mean blood pressure was significantly increased under Pcom (p < 0.001), while heart rate remained unchanged. Peak aortic valve velocity (Vmax) was slightly, but significantly decreased under Pcom (p = 0.03). However, Doppler velocity index and EOAAV by continuity equation were not affected by Pcom. CONCLUSION AS severity assessment by echocardiography was not dependent on the change of LV afterload imposed by Pcom. AV Vmax was slightly decreased with LV afterload increment, but these changes were too small to alter treatment plan of AS patients. EOAAV and Doppler velocity index are more stable parameters for AS severity assessment.
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Affiliation(s)
- Sung-A Chang
- Division of Cardiology, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Torii R, El-Hamamsy I, Donya M, Babu-Narayan SV, Ibrahim M, Kilner PJ, Mohiaddin RH, Xu XY, Yacoub MH. Integrated morphologic and functional assessment of the aortic root after different tissue valve root replacement procedures. J Thorac Cardiovasc Surg 2012; 143:1422-8. [DOI: 10.1016/j.jtcvs.2011.12.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 12/02/2011] [Accepted: 12/14/2011] [Indexed: 10/28/2022]
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Torii R, Xu XY, El-Hamamsy I, Mohiaddin R, Yacoub MH. Computational biomechanics of the aortic root. ACTA ACUST UNITED AC 2011. [DOI: 10.5339/ahcsps.2011.16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Ryo Torii
- 1Qatar Cardiovascular Research Center, Doha,
Qatar
- 2Harefield Heart Science Centre, Imperial College London, Harefield,
UK
- 5Department of Chemical Engineering,
Imperial College London, London, UK
| | - Xiao Yun Xu
- 5Department of Chemical Engineering,
Imperial College London, London, UK
| | - Ismail El-Hamamsy
- 4Department of Cardiac Surgery, Montreal
Heart Institute, Montreal, Canada
| | - Raad Mohiaddin
- 3Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital and
Imperial College London, London, UK
| | - Magdi H. Yacoub
- 1Qatar Cardiovascular Research Center, Doha,
Qatar
- 2Harefield Heart Science Centre, Imperial College London, Harefield,
UK
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de Heer LM, Budde RPJ, Mali WPTM, de Vos AM, van Herwerden LA, Kluin J. Aortic root dimension changes during systole and diastole: evaluation with ECG-gated multidetector row computed tomography. Int J Cardiovasc Imaging 2011; 27:1195-204. [PMID: 21359833 PMCID: PMC3230759 DOI: 10.1007/s10554-011-9838-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 02/16/2011] [Indexed: 10/27/2022]
Abstract
Cardiac pulsatility and aortic compliance may result in aortic area and diameter changes throughout the cardiac cycle in the entire aorta. Until this moment these dynamic changes could never be established in the aortic root (aortic annulus, sinuses of Valsalva and sinotubular junction). The aim of this study was to visualize and characterize the changes in aortic root dimensions during systole and diastole with ECG-gated multidetector row computed tomography (MDCT). MDCT scans of subjects without aortic root disease were analyzed. Retrospectively, ECG-gated reconstructions at each 10% of the cardiac cycle were made and analyzed during systole (30-40%) and diastole (70-75%). Axial planes were reconstructed at three different levels of the aortic root. At each level the maximal and its perpendicular luminal dimension were measured. The mean dimensions of the total study group (n = 108, mean age 56 ± 13 years) do not show any significant difference between systole and diastole. The individual dimensions vary up to 5 mm. However, the differences range between minus 5 mm (diastolic dimension is greater than systolic dimensions) and 5 mm (vice versa). This variability is independent of gender, age, height and weight. This study demonstrated a significant individual dynamic change in the dimensions of the aortic root. These results are highly unpredictable. Most of the healthy subjects have larger systolic dimensions, however, some do have larger diastolic dimensions.
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Affiliation(s)
- Linda M de Heer
- Department of Cardio-Thoracic Surgery, Division of Heart and Lungs, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands.
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Lang RM, Tsang W, Weinert L, Mor-Avi V, Chandra S. Valvular Heart Disease. J Am Coll Cardiol 2011; 58:1933-44. [DOI: 10.1016/j.jacc.2011.07.035] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 07/14/2011] [Accepted: 07/18/2011] [Indexed: 10/16/2022]
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Troiani D, Manni E. The work by Giulio Ceradini in explaining the mechanism of semilunar cardiac valve function. ADVANCES IN PHYSIOLOGY EDUCATION 2011; 35:110-113. [PMID: 21652491 DOI: 10.1152/advan.00071.2010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Using an excised pig heart preparation with tubes, a manometer, and a visualizing apparatus, Giulio Ceradini, an Italian physiologist working in the years of 1871-1872 in Carl Ludwig's famous laboratory in Leipzig, Germany, illustrated the mechanism of closure of the semilunar valves. He was the first to conceive that the closure of the heart valves depends not on a static back pressure nor upon eddies but is primarily the consequence of the decelerated systolic efflux. This pioneer research of Ceradini was first published in German in 1872 (4). The purpose of the present report is to revisit Ceradini's pioneering experiments and his interpretation of heart valve closure, which remains as true as it was in 1872.
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Affiliation(s)
- Diana Troiani
- Institute of Human Physiology, School of Medicine, Catholic University, Rome, Italy.
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Late Outcomes Following Freestyle Versus Homograft Aortic Root Replacement. J Am Coll Cardiol 2010; 55:368-76. [DOI: 10.1016/j.jacc.2009.09.030] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 09/28/2009] [Accepted: 09/30/2009] [Indexed: 11/23/2022]
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30
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El-Hamamsy I, Chester AH, Yacoub MH. Cellular regulation of the structure and function of aortic valves. J Adv Res 2010. [DOI: 10.1016/j.jare.2010.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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Hjortnaes J, Bouten CV, Van Herwerden LA, Gründeman PF, Kluin J. Translating Autologous Heart Valve Tissue Engineering from Bench to Bed. TISSUE ENGINEERING PART B-REVIEWS 2009; 15:307-17. [DOI: 10.1089/ten.teb.2008.0565] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Jesper Hjortnaes
- Division of Heart & Lungs, Department of Clinical and Experimental Cardio-Thoracic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Carlijn V.C. Bouten
- Division of Heart & Lungs, Department of Clinical and Experimental Cardio-Thoracic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
- Cell & Tissue Engineering Laboratory, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Lex A. Van Herwerden
- Division of Heart & Lungs, Department of Clinical and Experimental Cardio-Thoracic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Paul F. Gründeman
- Division of Heart & Lungs, Department of Clinical and Experimental Cardio-Thoracic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Jolanda Kluin
- Division of Heart & Lungs, Department of Clinical and Experimental Cardio-Thoracic Surgery, University Medical Center Utrecht, Utrecht, The Netherlands
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Virag Z, Lulić F. Modeling of aortic valve dynamics in a lumped parameter model of left ventricular-arterial coupling. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11565-008-0051-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Chester AH, Kershaw JDB, Sarathchandra P, Yacoub MH. Localisation and function of nerves in the aortic root. J Mol Cell Cardiol 2008; 44:1045-1052. [PMID: 18485360 DOI: 10.1016/j.yjmcc.2008.03.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 02/19/2008] [Accepted: 03/19/2008] [Indexed: 11/25/2022]
Abstract
Neural structures have been shown to be present in valve cusp tissue. We aimed to characterise the influence of neuronal stimulation on the component structures of the aortic root and cusps. Specimens of sinus, sinotubular junction (STJ), annulus and cusp tissue were dissected from porcine aortic roots and either stimulated with electrical field stimulation (EFS) in isolated tissue baths or fixed for immunohistochemical characterisation of neuronal structures. Sinus, STJ and annular tissue all gave tetrodotoxin-sensitive, frequency-dependent contractions in response to EFS. Contractions in annular tissue were only evident in tissue from the left- and non-coronary cusps, but not from the right-coronary cusp. Cusp tissue gave no contractile response to EFS, however in the presence of 1 mumol tetrodotoxin a strong contractile response was evident. This contractile response was unmasked when cusp tissue was stimulated in the presence of a nitric oxide synthase or guanylate cyclase inhibitors. Immunohistochemical analysis identified a network of neurofilament positive fibers in tissue from all aortic root structures that were associated with the presence of tyrosine hydroxylase and choline acetyl transferase. The nerve fibers in cusp tissue were in close proximity to the endothelial surface and demonstrated positive staining for neuronal nitric oxide synthase. Nerves in the aortic valve exert a nitric oxide-mediated neurogenic dilator tone in cusp tissue and are capable of producing contractile responses in different components of the aortic root. These responses could influence valve function in health and disease.
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Affiliation(s)
- Adrian H Chester
- Department of Cardiothoracic Surgery, National Heart and Lung Institute Imperial College London Heart Science Centre, Harefield, Middlesex UB9 6JH, UK.
| | - John D B Kershaw
- Department of Cardiothoracic Surgery, National Heart and Lung Institute Imperial College London Heart Science Centre, Harefield, Middlesex UB9 6JH, UK
| | - Padmini Sarathchandra
- Department of Cardiothoracic Surgery, National Heart and Lung Institute Imperial College London Heart Science Centre, Harefield, Middlesex UB9 6JH, UK
| | - Magdi H Yacoub
- Department of Cardiothoracic Surgery, National Heart and Lung Institute Imperial College London Heart Science Centre, Harefield, Middlesex UB9 6JH, UK
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Settepani F, Szeto WY, Pacini D, De Paulis R, Chiariello L, Di Bartolomeo R, Gallotti R, Bavaria JE. Reimplantation valve-sparing aortic root replacement in Marfan syndrome using the Valsalva conduit: an intercontinental multicenter study. Ann Thorac Surg 2007; 83:S769-73; discussion S785-90. [PMID: 17257924 DOI: 10.1016/j.athoracsur.2006.10.084] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2006] [Revised: 10/05/2006] [Accepted: 10/24/2006] [Indexed: 11/21/2022]
Abstract
BACKGROUND Introduced by DePaulis in 2000, the Gelweave Valsalva graft (Sulzer Vascutek, Refrewshire, Scotland) is a modified Dacron conduit (DuPont, Wilmington, DE), with prefashioned sinuses of Valsalva. The aim of this study was to evaluate the mid-term results of the reimplantation valve-sparing aortic root replacement using the Gelweave Valsalva prosthesis in Marfan syndrome patients. METHODS A retrospective review was performed of 35 patients with Marfan syndrome in four centers who underwent the reimplantation valve-sparing aortic root replacement using the Gelweave Valsalva prosthesis. RESULTS The patients were predominantly men, with a mean age of 36.5 +/- 12.6 years (range, 14 to 62 years). Two patients presented with acute type A dissections and underwent emergent operations. Elective hemiarch reconstruction using hypothermic circulatory arrest was required in 11 patients. Aortic valve cusp repair was performed in 2 patients. There were no operative or hospital deaths, and no patients died during follow-up. The mean follow-up was 19 months (range, 1 to 60 months). Significant (>2+) aortic insufficiency (AI), requiring aortic valve replacement, developed in 3 patients during follow-up that requiring aortic valve replacement. The 5-year freedom from reoperation owing to structural valve deterioration was 88.9% +/- 8.1%. There were no episodes of clinically significant thromboembolism. CONCLUSIONS Reimplantation valve-sparing aortic root replacement with the Gelweave Valsalva prosthesis in Marfan patients provides satisfactory mid-term results, thus encouraging further use of this type of repair. However, long-term results are needed in order to define the durability of this technique.
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Lodato JA, Weinert L, Baumann R, Coon P, Anderson A, Kim A, Fedson S, Sugeng L, Lang RM. Use of 3-Dimensional Color Doppler Echocardiography to Measure Stroke Volume in Human Beings: Comparison with Thermodilution. J Am Soc Echocardiogr 2007; 20:103-12. [PMID: 17275694 DOI: 10.1016/j.echo.2006.07.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Indexed: 11/22/2022]
Abstract
BACKGROUND The availability of accurate noninvasive measurements of cardiac output (CO) would be useful in assessing disease severity and the effects of therapeutic interventions in many different clinical settings. Current noninvasive methods are limited by their dependence on geometric assumptions. We tested the feasibility of a new technique for CO measurements based on 3-dimensional color Doppler echocardiographic (3D-CD) imaging. OBJECTIVE We sought to compare the accuracy of CO determination in human beings as measured by 3D-CD and conventional 2-dimensional echocardiography (2DE) using thermodilution as the gold standard for comparison. METHODS Simultaneous 3D-CD, 2DE, and thermodilution data were acquired in 47 patients postcardiac transplantation with good acoustic windows who required routine hemodynamic evaluation with a pulmonary artery catheter. Data were stored on compact disc and analyzed offline using custom software. Echocardiographic data were compared against thermodilution using linear regression and Bland-Altman analysis. RESULTS Correlation coefficients for 3D-CD and 2DE of the left ventricular outflow tract were r = 0.94 and r = 0.78, respectively. Correlation coefficients for 3D-CD and 2DE of the mitral valve were r = 0.93 and r = 0.75, respectively. Compared with 2DE, 3D-CD demonstrated a smaller bias and narrower limits of agreement in the left ventricular outflow tract (-1.84 +/- 16.8 vs -8.6 +/- 36.2 mL) and mitral valve inflow (-0.2 +/- 15.6 vs 10.0 +/- 26 mL). CONCLUSION The 3D-CD determination of CO is feasible and accurate. Compared with previous noninvasive modalities, 3D-CD has the advantages of independence of geometric assumptions and ease of image acquisition and analysis.
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Affiliation(s)
- Joseph A Lodato
- Noninvasive Cardiac Imaging Laboratory, Section of Cardiology, Department of Internal Medicine, University of Chicago Medical Center, Chicago, Illinois 60637, USA
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Fries R, Graeter T, Aicher D, Reul H, Schmitz C, Böhm M, Schäfers HJ. In vitro comparison of aortic valve movement after valve-preserving aortic replacement. J Thorac Cardiovasc Surg 2006; 132:32-7. [PMID: 16798299 DOI: 10.1016/j.jtcvs.2006.02.034] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Revised: 01/11/2006] [Accepted: 02/06/2006] [Indexed: 10/24/2022]
Abstract
OBJECTIVE In aortic valve regurgitation and aortic dilatation, preservation of the aortic valve is possible by means of root remodeling (Yacoub procedure) or valve reimplantation (David procedure). In vivo studies suggest that reimplantation might substantially influence aortic valve-motion characteristics. Evaluation of aortic valve movement in vivo, however, is technically limited and is difficult to standardize. We evaluated the aortic valve-motion pattern echocardiographically in vitro after reimplantation and remodeling. METHODS By using aortic roots of house pigs (aortoventricular diameter, 22 mm) a Yacoub procedure (22-mm graft; group Y, n = 5) or a David I procedure (24-mm graft; group D, n = 5) was performed. Roots after supracommissural replacement (22-mm graft; group C, n = 5) served as control valves. In an electrohydraulic, computer-controlled pulse duplicator the valves were tested at flows of 2, 4, 7, and 9 L/min. Echocardiographically assessed parameters were rapid valve-opening velocity, slow valve-closing velocity, rapid valve-closing velocity, rapid valve-opening time, rapid valve-closing time, ejection time, maximum valve opening, slow valve-closing displacement, and maximum flow velocity. RESULTS Mean rapid valve-opening velocity and mean rapid valve-closing velocity at a cardiac output of 2 to 9 L/min were fastest in group D (rapid valve-opening velocity: 69 +/- 10 cm/s [group D] vs 39 +/- 4 cm/s [group Y] vs 42 +/- 4 cm/s [group C], P = .0041; rapid valve-closing velocity: 22 +/- 2 cm/s [group D] vs 16 +/- 2 cm/s [group Y] vs 17 +/- 1 cm/s [group C], P = .0272), and slow valve-closing velocity was slowest in group D (0.2 +/- 0.1 cm/s [group D] vs 1.0 +/- 0.3 cm/s [group Y] vs 0.6 +/- 0.1 cm/s [group C], P = .0063). With increasing cardiac output, the difference in rapid valve-opening velocity between the groups increased, the difference in slow valve-closing velocity remained unchanged, and the difference in rapid valve-closing velocity decreased. CONCLUSIONS In this standardized experimental setting remodeling of the aortic valve provides significantly smoother valve movements. This might contribute to preservation of a better valve performance during long-term follow-up.
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Affiliation(s)
- Roland Fries
- Department of Cardiology, University Hospital Homburg, Homburg/Saar, Germany.
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Schmidt C, Theilmeier G, Van Aken H, Flottmann C, Wirtz SP, Kehl HG, Hoffmeier A, Berendes E. Effective systolic orifice area of the aortic valve: implications for Doppler echocardiographic cardiac output determinations. Acta Anaesthesiol Scand 2005; 49:1135-41. [PMID: 16095455 DOI: 10.1111/j.1399-6576.2005.00763.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Substantial research using echocardiography has established that stroke volume (SV) or cardiac output (CO) can be measured non-invasively at the level of the aortic valve (AV) with high accuracy. Stroke volume is the product of the velocity time integral occurring at the sampling site and the effective systolic AV orifice area (AVOAeff). Nevertheless, a generally accepted method for the determination of AVOAeff is still lacking. METHODS Aortic valve OAeff was measured in 228 consecutive patients scheduled for coronary artery surgery. Two widely adopted methods were applied to approximate the constantly changing orifice area of the AV: (1) the circular orifice model (AVOA-CM), and (2) the triangular orifice model (AVOA-TM). Aortic valve OA-CM assumes the shape of a circle as an appropriately time averaged geometrical model, and AVOA-TM takes the shape of an equilateral triangle for granted. RESULTS The AV was easily imaged by echocardiography in both short- and long-axis views in all patients. Relying on AVOA-CM, AVOAeff was 3.49+/-0.77 cm2. AVOA-TM estimates were 2.80+/-0.55 cm2 (mean+/-SD). The results did not agree (bias analysis). CONCLUSIONS The echocardiographic measurement of SV or CO at the level of the AV has to be reconsidered.
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Affiliation(s)
- C Schmidt
- Department of Anesthesiology and Surgical Intensive-Care Medicine, University of Münster Hospital, Münster, Germany.
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Kadem L, Dumesnil JG, Rieu R, Durand LG, Garcia D, Pibarot P. Impact of systemic hypertension on the assessment of aortic stenosis. Heart 2005; 91:354-61. [PMID: 15710719 PMCID: PMC1768735 DOI: 10.1136/hrt.2003.030601] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To determine the effect of systemic arterial hypertension on the indices of aortic stenosis (AS) severity. METHODS A severe supravalvar AS was created in 24 pigs. The maximum and mean pressure gradients across the stenosis were measured by Doppler echocardiography and by catheterisation. Both echocardiography and catheter data were used to calculate stenosis effective orifice area, energy loss coefficient, and peak systolic left ventricular wall stress. Measurements were taken both at normal aortic pressures and during hypertension induced by banding of the distal thoracic aorta in 14 pigs and by intravenous administration of phenylephrine in 10 pigs. RESULTS During hypertension, systemic arterial resistance downstream from the stenosis increased greatly (all animals: 71 (40)%), whereas total systemic arterial compliance decreased significantly (-38 (21)%). Hypertension resulted in a moderate increase in effective orifice area (29 (14)%) and energy loss coefficient (25 (17)%) and substantial decreases in catheter gradients (maximum: -40 (20)%; mean: -43 (20)%; peak to peak: -70 (23)%) and Doppler gradients (maximum: -35 (17)%; mean: -37 (16)%). In multivariate analysis, peak to peak gradient was significantly (p < 0.001) related to the energy loss coefficient, mean flow rate, and arterial compliance, whereas maximum and mean catheter gradients were related only to the energy loss coefficient and flow rate. Of major importance, maximum systolic left ventricular wall stress increased greatly during hypertension (43 (23)%). CONCLUSIONS The severity of AS may be partially masked by the presence of coexisting hypertension. The markers of AS severity should thus be interpreted with caution in hypertensive patients and be re-evaluated when the patient is in a normotensive state.
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Affiliation(s)
- L Kadem
- Research Centre of Laval Hospital, Quebec Heart Institute, Laval University, Sainte-Foy, Quebec, Canada
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Scharfschwerdt M, Misfeld M, Sievers HH. The influence of a nonlinear resistance element upon in vitro aortic pressure tracings and aortic valve motions. ASAIO J 2005; 50:498-502. [PMID: 15497392 DOI: 10.1097/01.mat.0000137038.03251.35] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
In vitro testing of biological heart valves requires pressure and flow waveforms closely simulating natural conditions, which are mainly influenced by the characteristics of the vascular system. Simulation of the arterial function in artificial circulations was mostly performed by the useful Windkessel model but sometimes failed by generating inadequate systolic pressures. The integration of a novel nonlinear resistance element may improve the Windkessel function. Native porcine aortic valves were studied in a mock circulation with a novel nonlinear resistance element combined with the Windkessel compared with an aperture plate resistance. Pressure and flow measurements were performed at varying heart rates and stroke volumes and analyzed in the time and frequency domain. Aortic valve motions were evaluated using high speed video recording. With the classical afterload configuration including an aperture plate resistance, the pressure tracings showed a nonphysiologic decrease of pressure during systole after early peak pressure. By integration of the novel nonlinear resistance, peak systolic pressure occured later, peak pressure was higher, and the pressure waveform was more physiologically shaped. Leaflet motions of the aortic valves were less oscillatory and compared well with in vivo characteristics. In conclusion, a novel nonlinear resistance element in a mock circulation has the potential to provide more physiologic aortic pressure waveforms as influencing aortic valve dynamics and thus may be a helpful tool for investigation of biological heart valves.
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Yacoub MH, Takkenberg JJM. Will heart valve tissue engineering change the world? ACTA ACUST UNITED AC 2005; 2:60-1. [PMID: 16265355 DOI: 10.1038/ncpcardio0112] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2004] [Accepted: 12/21/2004] [Indexed: 11/09/2022]
Affiliation(s)
- M H Yacoub
- Heart Science Center, Imperial College London, Harefield, UK
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Garcia D, Pibarot P, Landry C, Allard A, Chayer B, Dumesnil JG, Durand LG. Estimation of aortic valve effective orifice area by Doppler echocardiography: effects of valve inflow shape and flow rate. J Am Soc Echocardiogr 2004; 17:756-65. [PMID: 15220901 DOI: 10.1016/j.echo.2004.03.030] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND The effective orifice area (EOA) is the standard parameter for the clinical assessment of aortic stenosis severity. It has been reported that EOA measured by Doppler echocardiography does not necessarily provide an accurate estimate of the cross-sectional area of the flow jet at the vena contracta, especially at low flow rates. The objective of this study was to test the validity of the Doppler-derived EOA. METHODS Triangular and circular orifice plates, funnels, and bioprosthetic valves were inserted into an in vitro aortic flow model and were studied under different physiologic flow rates corresponding to cardiac outputs varying from 1.5 to 7 L/min. For each experiment, the EOA was measured by Doppler and compared with the catheter-derived EOA and with the EOA derived from a theoretic formula. In bioprostheses, the geometric orifice area (GOA) was estimated from images acquired by high-speed video recording. RESULTS There was no significant difference between the EOA derived from the 3 methods with the rigid orifices (Doppler vs catheter: y = 0.97x +0.18 mm(2), r(2) = 0.98; Doppler vs theory: y = 1.00x -3.60 mm(2), r(2) = 0.99). Doppler EOA was not significantly influenced by the flow rate in rigid orifices. As predicted by theory, the average contraction coefficient (EOA/GOA) was around 0.6 in the orifice plates and around 1.0 in the funnels. In the bioprosthetic valves, both EOA and GOA increased with increasing flow rate whereas contraction coefficient was almost constant with an average value of 0.99. There was also a very good concordance between EOA and GOA (y = 0.94x +0.05 mm(2), r(2) = 0.88). CONCLUSIONS In rigid aortic stenosis, the Doppler EOA is much less flow dependent than generally assumed. Indeed, it depends mainly on the GOA and the inflow shape (flat vs funnel-shaped) of the stenosis. The flow dependence of Doppler EOA observed in clinical studies is likely a result of a variation of the valve GOA or of the valve inflow shape and not an inherent flow dependence of the EOA derived by the continuity equation.
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Affiliation(s)
- Damien Garcia
- Institut de Recherches Cliniques de Montréal, Canada
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Affiliation(s)
- Magdi H Yacoub
- Imperial College School of Medicine, Heart Science Centre, Harefield Research Foundation, Harefield, Middlesex, UK.
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Sripathi VC, Kumar RK, Balakrishnan KR. Further insights into normal aortic valve function: role of a compliant aortic root on leaflet opening and valve orifice area. Ann Thorac Surg 2004; 77:844-51. [PMID: 14992884 DOI: 10.1016/s0003-4975(03)01518-2] [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] [Accepted: 06/23/2003] [Indexed: 11/19/2022]
Abstract
BACKGROUND This study aims to find the fundamental differences in the mechanism of opening and closing of a normal aortic valve and a valve with a stiff root, using a dynamic finite element model. METHODS A dynamic, finite element model with time varying pressure was used in this study. Shell elements with linear elastic properties for the leaflet and root were used. Two different cases were analyzed: (1) normal leaflets inside a compliant root, and (2) normal leaflets inside a stiff root. RESULTS A compliant aortic root contributes substantially to the smooth and symmetrical leaflet opening with minimal gradients. In contrast, the leaflet opening inside a stiff root is delayed, asymmetric, and wrinkled. However, this wrinkling is not associated with increased leaflet stresses. In compliant roots, the effective valve orifice area can substantially increase because of increased root pressure and transvalvular gradients. In stiff roots this effect is strikingly absent. CONCLUSIONS A compliant aortic root contributes substantially to smooth and symmetrical leaflet opening with minimal gradients. The compliance also contributes much to the ability of the normal aortic valve to increase its effective valve orifice in response to physiologic demands of exercise. This effect is strikingly absent in stiff roots.
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Handke M, Heinrichs G, Beyersdorf F, Olschewski M, Bode C, Geibel A. In vivo analysis of aortic valve dynamics by transesophageal 3-dimensional echocardiography with high temporal resolution. J Thorac Cardiovasc Surg 2003; 125:1412-9. [PMID: 12830062 DOI: 10.1016/s0022-5223(02)73604-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Knowledge of aortic valve function has been obtained from experimental studies. The aim of the present study was to investigate characteristics of aortic valve motion in humans. METHODS Fifty-six patients were studied: 19 with normal valve and good systolic left ventricular function (Group NL), 12 with normal valve and reduced left ventricular function (Group CMP), and 25 with aortic stenosis and good left ventricular function (Group AS). The frame rate was doubled (50 Hz) compared with previous 3-dimensional systems. A mean of 38 +/- 9 images were acquired per cardiac cycle, with 14 +/- 4 images during the systole. The changes in shape and orifice area were analyzed over time. RESULTS With normal valves, valve movement proceeded in 3 phases: rapid opening, slow closing, rapid closing. Stenotic valves showed a slower opening and closing movement. The times to maximum opening in Groups NL, CMP, AS were 76 +/- 30, 88 +/- 18 (P =.06), and 130 +/- 29 (P <.01) ms, respectively. It was inversely correlated to the maximum orifice area (r = -0.59, P <.001). The opening velocities in Groups NL, CMP, AS were 42 +/- 23, 28 +/- 9 (P <.05), and 5 +/- 2 (P <.001) cm(2)/s, respectively. There was a close correlation between the opening velocity and the maximum orifice area (r = 0.87, P <.001). Slow valve closings occurred at a velocity of 8.0 +/- 5.2, 5.3 +/- 2.0 (P =.21), 2.8 +/- 1.1 (P <.01) cm(2)/s, respectively, and rapid closings in Groups NL and CMP at 50 +/- 23, 29 +/- 8 (P <.01) cm(2)/s. The results show good agreement with experimental data. CONCLUSION Rapid aortic valve movement can be recorded by 3-dimensional echocardiography and analyzed quantitatively. Time and velocity indices of valve dynamics are influenced by valvular and myocardial factors. A comparable in vivo analysis is not possible with any other imaging procedure.
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Affiliation(s)
- Michael Handke
- Department of Cardiology and Angiology, Albert-Ludwigs-University, Freiburg, Germany.
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Misfeld M, Chester AH, Sievers HH, Yacoub MH. Biological mechanisms influencing the function of the aortic root. J Card Surg 2002; 17:363-8. [PMID: 12546088 DOI: 10.1111/j.1540-8191.2001.tb01159.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Optimal function of the aortic root relies upon the ability of its component structures to move in a coordinated fashion. Some of the cells that make up the structures of the aortic root have been shown to contain nerves, receptors, and contractile elements. The ability to contract or relax may contribute to the successful function of the valve by allowing it to move in a coordinated manner in response to biological stimuli. It is known that cusp tissue receives primary, sensory, and autonomic nerves, suggesting a role for neuronal regulation of cusp function. In addition, cusp tissue has been shown to express a wide variety of receptors and to contract to a range of common vasoactive agents. The cells that constitute the valve have also shown secretory and proliferative responses. The biological signals that mediate the cross-talk between the different parts of the root have not been established. This review will examine the mechanisms that have been documented to be present and to assess their potential contribution in affecting aortic valve function.
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Affiliation(s)
- M Misfeld
- Department of Cardiothoracic Surgery, Heart Science Centre, Harefield Hospital, N.H.L.I., Imperial College of Science Technology and Medicine, Middlesex, United Kingdom
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De Paulis R, De Matteis GM, Nardi P, Scaffa R, Buratta MM, Chiariello L. Opening and closing characteristics of the aortic valve after valve-sparing procedures using a new aortic root conduit. Ann Thorac Surg 2001; 72:487-94. [PMID: 11515887 DOI: 10.1016/s0003-4975(01)02747-3] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The durability of aortic valve-sparing procedures is negatively affected by increased leaflet stress in the absence of normally shaped sinuses of Valsalva. We compared valve motion after remodeling procedures using a standard conduit and a specifically designed aortic root conduit. METHODS Echocardiographic studies of the aortic valve dynamics were performed in 14 patients after remodeling of the aortic root (7 standard conduits, group A; 7 new conduits, group B) and in 7 controls (group C). Opening and closing leaflet velocities and percent of slow closing leaflet displacement were measured. Root distensibility and the pressure strain of the elastic modulus were measured at all root levels. RESULTS Root distensibility and the pressure strain of the elastic modulus were different in group A and B only at the sinuses (p < 0.001). Opening and closing leaflet velocities were not different among groups. Slow closing leaflet displacement was markedly more evident in group B patients (24.2%+/-1.9% versus 2.5%+/-1.9% in group A, p < 0.001) and similar to controls (22.1%+/-7.9%). CONCLUSIONS The new conduit guarantees dynamic features of the aortic valve leaflets superior to those obtained with standard conduits and more similar to normal subjects.
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Affiliation(s)
- R De Paulis
- Department of Cardiac Surgery, University of Rome, Tor Vergata, Italy.
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Gray PE, Perrino AC. Hemodynamic-induced changes in aortic valve area: implications for Doppler cardiac output determinations. Anesth Analg 2001; 92:584-9. [PMID: 11226082 DOI: 10.1097/00000539-200103000-00006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Monitoring cardiac output (CO) by transesophageal echocardiography involves measurements of ascending aortic flow and an initial measurement of aortic valve area (AVA). Hemodynamic-induced changes in AVA are a potential source of error for this simplified method. Our goal was to quantify these changes in AVA and their effects on CO calculations. In 17 anesthetized patients, a dobutamine infusion was titrated to achieve a 50% increase in ascending aortic flow velocity (V(max)). Hemodynamic and echocardiographic variables, including V(max) and planimetry of AVA, were determined at baseline and at maximal dobutamine dose. Dobutamine produced a 3.0 +/- 1.4 L/min increase in CO, a 54.5% +/- 19.6% increase in V(max), and a 50.6% +/- 34.2% increase in systolic blood pressure. AVA increased by 4.3% +/- 2.6% during dobutamine infusion (P < 0.001). The simplified CO method, which does not account for increases in AVA, produced a 0.32 +/- 0.24 L/min underestimation of CO. This investigation demonstrates hemodynamic-induced changes in AVA. The use of a single AVA measurement for all subsequent CO calculations introduces a clinically acceptable degree of error, supporting a simplified CO protocol requiring less probe manipulation and reduced procedural time. IMPLICATIONS An intraoperative dobutamine infusion was used to increase aortic blood flow and demonstrate hemodynamic-induced changes in aortic valve area. These valve-area changes affect the accuracy of Doppler cardiac output determinations.
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Affiliation(s)
- P E Gray
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut, USA.
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Gray PE, Perrino AC. Hemodynamic-Induced Changes in Aortic Valve Area: Implications for Doppler Cardiac Output Determinations. Anesth Analg 2001. [DOI: 10.1213/00000539-200103000-00006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Leyh RG, Schmidtke C, Sievers HH, Yacoub MH. Opening and closing characteristics of the aortic valve after different types of valve-preserving surgery. Circulation 1999; 100:2153-60. [PMID: 10571974 DOI: 10.1161/01.cir.100.21.2153] [Citation(s) in RCA: 241] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The surgical approach to aortic root aneurysm and/or dissection remains controversial. The use of valve-sparing operations, which are thought to have many advantages, is increasing. We hypothesized that the particular technique and type of surgery could influence valve motion characteristics and function. Therefore, we studied the instantaneous opening and closing characteristics of the aortic valve after the main 2 types of valve-sparing surgery. METHODS AND RESULTS In 20 patients (10 with tube replacement of the aortic root, group A; and 10 with separate replacement of the sinuses of Valsalva, group B) and 10 controls (group C), transthoracic and transesophageal studies on aortic valve dynamics were performed. Three distinct phases of aortic valve motion were identified. They were as follows: (1) a rapid opening, with a velocity of 20.9+/-4.2 cm/s in group C, 27.1+/-10.9 cm/s in group B (P=NS), and 58.3+/-18.4 cm/s in group A (group A versus group C, P<0. 001; group A versus group B, P=0.001); (2) a slow systolic closure, with 12.5+/-6.6% and 10.8+/-2.2% of maximal opening in groups C and B, respectively (P=NS), and 3.8+/-1.6% in group A (group A versus group C, P=0.001; group A versus group B, P<0.001); and (3) a rapid closing movement, with a velocity of 26.3+/-5.6 cm/s in group C, 32. 4+/-11.4 cm/s in group B (P=NS), and 21.8+/-3.5 cm/s in group A (group A versus group C, P=NS; group A versus group B, P=0.008). The pressure strain of the elastic modulus was different in groups C and B only at the commissures (682+/-145 g/cm(2) versus 1896+/-726 g/cm(2), respectively; P<0.001). At all root levels, the distensibility was reduced in group A (P<0.001). Systolic contact of aortic cusps and wall occurred only in group A. CONCLUSIONS Near-normal opening and closing characteristics can be achieved by a technique that preserves the shape and independent mobility of the sinuses of Valsalva.
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Affiliation(s)
- R G Leyh
- Department of Cardiac Surgery, Medical University of Lübeck, Lübeck, Germany
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Abstract
Although the aortic outflow and root (AoR) constitute a short channel connecting the left ventricle to the aorta, its different components have been shown to be highly specialized structures, interacting with each other as well as with surrounding structures, thus providing a "tale of dynamism and crosstalk." Thorough knowledge of the AoR and morphological and structural changes, that occur during pathological processes, can have important implications in evolving and executing surgical procedures designed to preserve and restore the "dynamism and crosstalk." The crown-shaped annulus, fibrous trigones, aortic cusps components, aortic sinuses, and the sinotubular junction share a dynamic coordinated behavior, which can be partially or completely restored in various repair or replacement procedures of the AoR. The interaction and the specific operations are presented with evidence supporting the notion that the dynamic behavior of the root does influence the pattern of instantaneous movements of the aortic cusps after different types of operations. Further studies are required to evaluate the influence of adopting these ideas on the long-term results of operative procedures.
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Affiliation(s)
- M H Yacoub
- Imperial College of Science, Technology, and Medicine, Harefield Hospital, Middlesex, United Kingdom.
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