Improved In Vitro Quantification of the Force Exerted by the Papillary Muscle on the Left Ventricular Wall: Three-Dimensional Force Vector Measurement System

Jensen, Morten Ø.; Fontaine, Arnold A.; Yoganathan, Ajit P.

doi:10.1114/1.1366672

Cited by 51 publications

(58 citation statements)

References 8 publications

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“…Predicted transmitral flow showed excellent agreement with published in vitro transmitral flow data from the Georgia Tech left heart simulator (JENSEN and FONTAINE, 2001). Specifically, the peak closing flow of 3.1 min -1 compared well with a measured peak closing flow of 3.6 min -1 (Fig.…”

Section: Flowsupporting

confidence: 67%

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Haemodynamic determinants of the mitral valve closure sound: A finite element study

Einstein

Kunzelman

Reinhall

et al. 2004

Med. Biol. Eng. Comput.

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Automatic acoustic classification and diagnosis of mitral valve disease remain outstanding biomedical problems. Although considerable attention has been given to the evolution of signal processing techniques, the mechanics of the first heart sound generation has been largely overlooked. In this study, the haemodynamic determinants of the first heart sound were examined in a computational model. Specifically, the relationship of the transvalvular pressure and its maximum derivative to the time-frequency content of the acoustic pressure was examined. To model the transient vibrations of the mitral valve apparatus bathed in a blood medium, a dynamic, non-linear, fluid-coupled finite element model of the mitral valve leaflets and chordae tendinae was constructed. It was found that the root mean squared (RMS) acoustic pressure varied linearly (r2= 0.99) from 0.010 to 0.259 mmHg, following an increase in maximum dP/dt from 415 to 12470 mm Hg s(-1). Over that same range, peak frequency varied non-linearly from 59.6 to 88.1 Hz. An increase in left-ventricular pressure at coaptation from 22.5 to 58.5mm Hg resulted in a linear (r2= 0.91) rise in RMS acoustic pressure from 0.017 to 1.41mm Hg. This rise in transmitral pressure was accompanied by a non-linear rise in peak frequency from 63.5 to 74.1 Hz. The relationship between the transvalvular pressure and its derivative and the time-frequency content of the first heart sound has been examined comprehensively in a computational model for the first time. Results suggest that classification schemes should embed both of these variables for more accurate classification.

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Section: Flowsupporting

confidence: 67%

“…6). The predicted peak papillary muscle force of 2.6N agreed well with the measured value of 2.5N at 80mmHg (JENSEN and FONTAINE, 2001). No attempt was made to normalise for potentially different anatomical or material properties or for different inputs.…”

Section: Discussionmentioning

confidence: 73%

Haemodynamic determinants of the mitral valve closure sound: A finite element study

Einstein

Kunzelman

Reinhall

et al. 2004

Med. Biol. Eng. Comput.

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“…With reference to the PM reaction forces, the values of 4.03 and 3.45 N for the anterolateral and posteromedial PMs, calculated for an 80 mm Hg pressure drop across the valve, are greater than the 2.5 N calculated by Einstein's model and observed in previous in vitro studies (Hashim et al 1997;Jensen et al 2001). This discrepancy is not due to the simulated annulus and PM motion, because when these are prevented similar values (3.46 and 3.68 N) are obtained.…”

Section: (G ) Commentscontrasting

confidence: 51%

Mitral valve finite-element modelling from ultrasound data: a pilot study for a new approach to understand mitral function and clinical scenarios

Votta

Caiani

Veronesi

et al. 2008

Phil. Trans. R. Soc. A.

108

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In the current scientific literature, particular attention is dedicated to the study of the mitral valve and to comprehension of the mechanisms that lead to its normal function, as well as those that trigger possible pathological conditions. One of the adopted approaches consists of computational modelling, which allows quantitative analysis of the mechanical behaviour of the valve by means of continuum mechanics theory and numerical techniques. However, none of the currently available models realistically accounts for all of the aspects that characterize the function of the mitral valve. Here, a new computational model of the mitral valve has been developed from in vivo data, as a first step towards the development of patient-specific models for the evaluation of annuloplasty procedures. A structural finiteelement model of the mitral valve has been developed to account for all of the main valvular substructures. In particular, it includes the real geometry and the movement of the annulus and papillary muscles, reconstructed from four-dimensional ultrasound data from a healthy human subject, and a realistic description of the complex mechanical properties of mitral tissues. Preliminary simulations allowed mitral valve closure to be realistically mimicked and the role of annulus and papillary muscle dynamics to be quantified.

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“…Few studies have examined chordae tendineae resistance following HPL treatment; Jensen et al quantified the maximum stretch chordae can endure [19]. The system that these authors developed allows the precise quantification and direction of the forces exerted on the posterior left ventricular wall during systole.…”

Section: Discussionmentioning

confidence: 98%

The use of a high-power laser on swine mitral valve chordae tendineae

et al. 2016

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Worldwide, rheumatic fever remains a significant cause of mitral valve insufficiency. It is responsible for approximately 90 % of early childhood valvular surgeries in Brazil. Elongated or flail chordae are frequently responsible and require surgical correction. The purpose of this study was to analyze and compare the histological tissues of the mitral valve chordae and the mechanical resistance generated by the chordae, both with and without the application of a high-power laser. Twenty normal porcine mitral valve chordae were measured and divided randomly into the following two groups: control group (not subjected to a high-power laser) and laser group (subjected to photonic irradiation). Laser surgery was performed under controlled conditions, using following parameters: λ = 980-nm wavelength, power = 3 W, and energy = 60 J. A mechanical test machine was used in combination with a subsequent histological study to measure chordae tensile properties. A histological analysis demonstrated a typical collagen bundle arrangement in the control group; however, under a particular reached temperature range (48), the collagen bundles assumed different arrangements in the laser group. Significant reductions in the chordae tendineae lengths and changes in their resistance in the laser group were observed, as these chordae exhibited less rigid fibers. The chordae tendineae of normal porcine valves subjected to a high-power laser exhibited its length reduction and less stiffness compared to the control group. A histological analysis of the laser treatment specimens demonstrated differences in collagen bundle spatial organization, following slight changes into tissue temperature.

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Improved In Vitro Quantification of the Force Exerted by the Papillary Muscle on the Left Ventricular Wall: Three-Dimensional Force Vector Measurement System

Cited by 51 publications

References 8 publications

Haemodynamic determinants of the mitral valve closure sound: A finite element study

Haemodynamic determinants of the mitral valve closure sound: A finite element study

Mitral valve finite-element modelling from ultrasound data: a pilot study for a new approach to understand mitral function and clinical scenarios

The use of a high-power laser on swine mitral valve chordae tendineae

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