| 1. |
- Carlhäll, Carljohan, 1973-
(författare)
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Annular dynamics of the human heart : novel echocardiographic approaches to assess ventricular function
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The complex myocardial fiber architecture of the left ventricle (LV) enables long-axis motion (annular excursion), short-axis motion and also a small torsional deformation throughout the cardiac cycle. The contribution of the long-axis motion has proven to be important in generating ventricular filling and emptying, and the analysis of annular excursion has become a well established diagnostic tool for the assessment of ventricular function. Cardiac motion can be accurately described with modem non-invasive imaging teclmiques, and this is important ground for deeper understanding and more reliable diagnosis of cardiovascular disease. The focus of this thesis was to provide new insights into cardiac pump function using variables originating from the annular excursion and dynamic changes in shape, applying both established and novel echocardiographic imaging approaches.The traditional method of evaluating systolic ventricular fimction according to the total annular excursion overestimates the excursion amplitude in relation to true systolic fimction. A novel method presented here, measurement of the systolic annular excursion, more accurately reflects the timing of true systole, and was applied both in patients with heart disease and in healthy subjects. To date, the form of asynchronous myocardial motion called postsystolic shortening (PSS) has mainly been observed in the setting of myocardial ischemia. The significance of PSS in hypertensive heart disease remains incompletely described. We found that a subgroup of hypertensive patients with PSS along the LV long-axis had signs of more severe cardiac involvement unrelated to the level of blood pressure. Endurance trained subjects showed a larger LV long-axis motion as compared to strength trained and untrained controls. Mitral annular (MA) excursion correlated strongly to LV stroke volume, end-diastolic volume and maximal oxygen consumption per body weight, but weakly to LV ejection fraction. These findings provide further evidence of the importance of annular excursion to normal cardiac performance. In order to assess the contribution of MA excursion and shape dynamics to total LV volume change in humans, a novel 4-dimensional transesophageal echocardiography teclmique was developed. The excursion of the annulus accounted for an important portion (19±3%) of the total LV filling and emptying in healthy human subjects. Furthermore, our findings elucidate an atrial influence on MA physiology in humans, as well as a sphincter-like action of the MA. These temporal changes may facilitate ventricular filling by annular expansion during early and mid diastole, and aid competent valve closure during the marked decrease in annular area during late diastole and early systole.
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| 2. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix A Marker Sites and Datafile Columns
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. A.1-A.3
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Datafiles (provided in this Appendix) associated with the six heart (H1-H6) study
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| 3. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix B NAC-MAD Composite Dataset
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. B.1-B.2
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Here, we describe an attempt to model, as accurately as possible in 3-D space, the geometric relationship between the various components of the left ventricle, the mitral valve, and the aortic valve during systole and diastole.
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| 4. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix C Computational Details
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. C.1-C.6
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix D Mitral Valve Animations
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. D.1-D.1
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The PowerPoint mitral valve animations in this Appendix can be accessed by double-clicking the filenames. Both side view (LEFT PANEL, looking from posterior to anterior) and top view (RIGHT PANEL, looking from base to apex) are provided. All graphs have Marker #22 at the origin, Marker #1 on the Z-axis, and Marker #18 in the X-Z plane. The animations can be stepped forward with the right arrow and backwards with the left arrow with time-steps of 16.67 ms. The left ventricular pressure associated with each time step is indicated by the black dot on the LVP curve imbedded in the graph. Hit Escape to exit each animation. The H1-H6 datasets are located in Appendix A.
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| 6. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix E COM Studies
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. E.1-E.1
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix P Pull Study Markers, Datasets, Protocal Schematic
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. P.1-P.2
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The PULL STUDY (see results in Chapter 28) was designed to assess the effect of posterior leaflet pressure on anterior leaflet edge geometry in the closed valve. Figure P1 shows the marker array and coordinate system used in this study.
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| 8. |
- Ingels, Jr, Neil B, et al.
(författare)
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Appendix S SOD and DOS Studies
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. S.1-S.8
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- in two views of S2 sod04r02. Table S.2 defines the DOS marker anatomical locations and Figure S.3 illustrates these locations in D5 dos21r01. Table S.3 defines the markers delineating the space-filling tetrahedral for volume calculations. Figures S.4A-F display these tetrahedral within the left atrium and left ventricle of SOD hearts S1, S2, S3, S7, S9, and S10.
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| 9. |
- Ingels, Jr, Neil B, et al.
(författare)
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Chapter 01 Anatomy and Marker Sites
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. 1.1-1.3
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Figure 1.1 is a view from a 3-D rendering of systolic geometry for the left ventricle, mitral valve, and aortic valve, computed as a composite from two experiments involving precise measurement of 83 marker sites. The methods used to obtain this 3-D dataset, including the full dataset file, are outlined in Appendix B. Note that in this systolic rendering, the aortic valve is open and the mitral valve is closed.
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| 10. |
- Ingels, Jr, Neil B, et al.
(författare)
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Chapter 02 Fibrous Mitral Annulus
- 2016
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Ingår i: Mitral Valve Mechanics. - : Linköping University Electronic Press. - 9789176859520 ; , s. 2.1-2.2
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A fibrous collagen wedge, pointing toward the left ventricle, separates the mitral valve and left atrium from the aortic valve. The portion of this wedge between the mitral and aortic valves is known as the aortic mitral curtain or the intervalvular fibrous curtain.
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