Dynamic three-dimensional imaging of the mitral valve and left ventricle by rapid sonomicrometry array localization

A numerical study was conducted to solve the three-dimensional Navier-Stokes equations for time-dependent flow in a compliant thin-walled, anatomically correct left ventricle during early systole. Model parameters were selected so that the simulation results could be compared to clinical data. The results produced endocardial wall motion which was consistent with human heart data, and velocity fields consistent with those occurring in a normally-contracting left ventricle. During isovolumetric contraction the posterior wall moved basally and posteriorly, while the septal wall moved apically and anteriorly. During ejection, the short axis of the left ventricle decreased 1.1 mm and the long axis increased 4.2 mm. At the end of the isovolumetric contraction, most of the flow field was moving form the apex toward the base with recirculation regions at the small pocket formed by the concave anterior leaflet, adjacent to the septal wall and near the left ventricular posterior wall. Fluid velocities in the outflow tract matched NMR data to within 10 percent. The results were also consistent with clinical measurements of mitral valve-papillary muscle apparatus displacement, and changes in the mitral valve annular area. The results of the present study show that the thin-walled, three-dimensional left ventricular model simulates observed normal heart phenomena. Validation of this model permits further studies to be performed which involve altered ventricular function due to a variety of cardiac diseases.

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A Three-Dimensional Computational Investigation of Intraventricular Fluid Dynamics: Examination Into the Initiation of Systolic Anterior Motion of the Mitral Valve Leaflets

Journal of Biomechanical Engineering ◽

10.1115/1.2792276 ◽

1995 ◽

Vol 117 (1) ◽

pp. 94-102 ◽

Cited By ~ 22

Author(s):

Ajit P. Yoganathan ◽

Jack D. Lemmon ◽

Young H. Kim ◽

Robert A. Levine ◽

Carol C. Vesier

Keyword(s):

Mitral Valve ◽

Left Ventricle ◽

Computer Model ◽

Three Dimensional ◽

Force Balance ◽

Central Portion ◽

Immersed Boundary ◽

Systolic Anterior Motion ◽

Initiation Mechanism ◽

Intraventricular Flow

Systolic anterior motion of the mitral valve leaflets (SAM) is a disease of the left ventricle which results from an abnormal force balance on the mitral valve. The mechanism by which is initiated is poorly understood, and a complete understanding of this mechanism is required for effective treatment of SAM. There are currently two theories for the initiation mechanism of SAM, the Venturi hypothesis and the altered papillary muscle-mitral valve geometry theory (PM-MV). The Venturi hypothesis states that abnormally high ejection velocities create Venturi forces which initiate SAM. The PM-MV theory asserts that SAM is the result of abnormally distributed chordal forces which are incapable of preventing SAM. To investigate the initiation mechanism of SAM, a computer model of early systolic flow in an anatomically-correct human left ventricle was developed using Peskin’s immersed boundary algorithm. The computer model was used to determine the effect of chordal force distribution and septal thickness of the intraventricular flow field. The results show that the degree of SAM is inversely proportional to the amount of chordal restraint applied to the central portion of the leaflets. Also, the results support the PM-MV theory and indicate the following: (i) fluid forces capable of initiating SAM as always present in a normal human ventricle; (ii) SAM does not occur normally because of the presence of chordal forces on the central portion of the mitral leaflet; (Hi) SAM will occur when these central chordal forces are sufficiently low; (iv) the extent of SAM is inversely proportional to these central chordal forces; and (v) Venturi forces alone can not cause SAM.

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The Transthoracic Three-Dimensional Echocardiography is Superior Technique to Reveal the Parachute-Like Asymmetric Mitral Valve

10.22541/au.162255564.49101997/v1 ◽

2021 ◽

Author(s):

Naka Saito ◽

Hideaki Ueda ◽

Yasuhiro Ichikawa

Keyword(s):

Mitral Valve ◽

Left Ventricle ◽

Muscle Tissue ◽

Papillary Muscle ◽

Three Dimensional ◽

Two Dimensional ◽

Parachute Mitral Valve ◽

Dimensional Echocardiography ◽

Three Dimensional Echocardiography ◽

Two Dimensional Echocardiography

A 13-year-old woman was underwent transthoracic two-dimensional echocardiography (2DE), which revealed that only a small anterolateral papillary muscle was observed in the left ventricle (LV). Additional transthoracic three-dimensional echocardiography (3DE) revealed the posteromedial-papillary muscle which has not correctly delaminated from the LV wall and directly connected to the mitral valve leaflets without tendon chordae. She was diagnosed as a parachute-like asymmetric mitral valve rather than a true-parachute mitral valve. It was difficult to understand the precise anatomy evaluated by the 2DE. However, additional 3DE provided helpful information to reveal the exact characteristics of papillary muscle tissue.

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Practical Perioperative Transoesophageal Echocardiography

10.1093/med/9780198759089.001.0001 ◽

2018 ◽

Cited By ~ 1

Keyword(s):

Mitral Valve ◽

Aortic Valve ◽

Mitral Valve Repair ◽

Three Dimensional ◽

Transoesophageal Echocardiography ◽

Valve Repair ◽

Three Dimensional Imaging ◽

Pericardial Disease ◽

Catheter Laboratory

Practical Perioperative Transoesophageal Echocardiography, 3rd edition, is a concise guide to the use of transoesophageal echocardiography (TOE) for patients undergoing cardiac surgical and interventional cardiological procedures. The text is aimed at anaesthetists and cardiologists, particularly those in training and those preparing for examinations. Three-dimensional imaging is integrated throughout the text. New to the third edition are chapters on mitral valve repair, aortic valve repair, TOE in the interventional catheter laboratory, and TOE assessment of pericardial disease. The first three chapters address the fundamentals of ultrasound imaging: physical principles, artefacts, image optimization, and quantitative echocardiography. Chapters 4 and 5 cover standard views, anatomical variants, and cardiac masses. Chapters 6 and 7 address left ventricular systolic and diastolic function, respectively. The subsequent eight chapters form the core of the book and deal with the cardiac valves and the thoracic aorta. Emphasis is placed on those aspects relevant to cardiac surgery; therefore, the mitral and aortic valves are afforded particular prominence. The role of three-dimensional imaging for the mitral valve is highlighted. Chapter 17 covers the emerging role of TOE for patients undergoing procedures in the catheter laboratory and covers topics such as transcatheter aortic valve replacement and edge-to-edge mitral valve repair. Chapter 18 provides an overview of the common congenital abnormalities encountered in adults. Two chapters address the important subjects of thoracic transplantation and mechanical cardiorespiratory support. Finally, Chapter 21 brings many threads from previous chapters together to describe the role of TOE in assessing haemodynamic instability.

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