Transmural left ventricular mechanics underlying torsional recoil during relaxation

Ashikaga, Hiroshi; Criscione, John C.; Omens, Jeffrey H.; Covell, James W.; Ingels, Neil B.

doi:10.1152/ajpheart.00575.2003

Cited by 137 publications

(152 citation statements)

References 46 publications

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“…These studies established that fiber orientation was a function of transmural location, with fiber direction being predominantly longitudinal in the endocardial region; transitioning into a circumferential direction in the midwall and becoming longitudinal again over the epicardial surface. Myofiber morphology was described either based on orientation of individual fibers or as multiple myocyte 'sheet' arrangements separated by extensive 'sheet cleavage' planes (17)(18)(19)(20). Some investigators depicted the LV as a complex nested continuum where the myofibers entwined to form a mechanical and electrical syncytium (21,22).…”

Section: Myofiber Architecture Of the Left Ventriclementioning

confidence: 99%

Left Ventricular Form and Function Revisited: Applied Translational Science to Cardiovascular Ultrasound Imaging

Sengupta

Krishnamoorthy

Kořínek

et al. 2007

Journal of the American Society of Echocardiography

287

196

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Tissue Doppler imaging (TDI) and TDI-derived strain imaging are robust physiologic tools used for the noninvasive assessment of regional myocardial function. Due to high temporal and spatial resolution, regional function can be assessed for each phase of the cardiac cycle and within the transmural layers of the myocardial wall. Newer techniques that measure myocardial motion by speckle tracking in grayscale images have overcome the angle dependence of TDI strain, allowing for measurement of 2-dimensional strain and cardiac rotation. TDI, TDI strain, and speckle tracking may provide unique information that deciphers the deformation sequence of complexly oriented myofibers in the left ventricular wall. The data are, however, limited. This review examines the structure and function of the left ventricle relative to the potential clinical application of TDI and speckle tracking in assessing the global mechanical sequence of the left ventricle in vivo.The spiral arrangement of muscle fibers in the heart is reminiscent of spiral and vortex patterns in nature, ranging from small organelles and whirlpools to hurricanes and rotational patterns of the galaxies (1-5). Vortex patterns link two fundamental forms of motion that work in close balance: an inner, rapidly descending swirl and an outer, less rapid, ascending rotation (4) ( Fig. 1 A-C). These counterdirectional movements of a vortex produce suction and expulsion forces that have been exploited for designing energy efficient propellers and turbines (6). Likewise, experimental and mathematical modeling of the clockwise and counterclockwise spiral loops of myofibers in the left ventricle (LV) has shown that counterdirectional geometry provides an efficient distribution of regional stresses and strains (7). Conversely, altered ventricular geometry resulting from cardiac remodeling, regional myocardial dysfunction, or asynchronous conduction distort the efficiency of the loading and expulsion dynamics (8,9). In this review, we associate the LV myofiber architecture to the spatiotemporal sequence of regional deformations occurring during normal cardiac contraction and relaxation. We further elucidate experimental observations, which explore the application of tissue Doppler imaging (TDI) and 2-dimensional ultrasound speckle tracking for delineation of the synchronous mechanical shortening and lengthening sequences of the human LV.Address reprint requests to Marek Belohlavek, Division of Cardiovascular Diseases, Mayo Clinic, 13400 East Shea Boulevard Scottsdale, AZ 85259, E-mail address for author named in reprint line: Belohlavek.marek@mayo.edu Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect th...

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Section: Myofiber Architecture Of the Left Ventriclementioning

confidence: 99%

Left Ventricular Form and Function Revisited: Applied Translational Science to Cardiovascular Ultrasound Imaging

Sengupta

Krishnamoorthy

Kořínek

et al. 2007

Journal of the American Society of Echocardiography

287

196

View full text Add to dashboard Cite

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“…101 Measuring longitudinal or circumferential shear is another promising approach to the assessment of torsion with speckle tracking, allowing full assessment of overall deformation in addition to three-dimensional strains and investigation of regional differences in torsion. 102 Hypertension, like other progressive myocardial diseases for example, coronary artery disease and hypertrophic cardiomyopathy, preferentially affects subendocardial function and the longitudinal fibres running along it. 103 The epicardial function may remain relatively unaffected.…”

Section: 66mentioning

confidence: 99%

Hypertension and heart failure: a dysfunction of systole, diastole or both?

et al. 2008

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The pathological myocardial hypertrophy associated with hypertension contains the seed for further maladaptive development. Increased myocardial oxygen consumption, impaired epicardial coronary perfusion, ventricular fibrosis and remodelling, abnormalities in long-axis function and torsion, cause, to a varying degree, a mixture of systolic and diastolic abnormalities. In addition, chronotropic incompetence and peripheral factors such as lack of vasodilator reserve and reduced arterial compliance further affect cardiac output particularly on exercise. Many of these factors are common to hypertensive heart failure with a normal ejection fraction as well as systolic heart failure. There is increasing evidence that these apparently separate phenotypes are part of a spectrum of heart failure differing only in the degree of ventricular remodelling and volume changes. Furthermore, dichotomizing heart failure into systolic and diastolic clinical entities has led to a paucity of clinical trials of therapies for heart failure with a normal ejection fraction. Therapies aimed at reversing myocardial fibrosis, and targets outside the heart such as enhancing vasodilator reserve and improving chronotropic incompetence deserve further study and may improve the exercise capacity of hypertensive heart failure patients. Hypertension heart disease with heart failure is simply not a dysfunction of systole and diastole. Other peripheral factors including heart rate and vasodilator response with exercise may deserve equal attention in an attempt to develop more effective treatments for this disorder.

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“…When data from seven hearts were combined, a bimodal distribution of angles was found with two distinct orientations of the cardiac laminar structure lying on average at 45.5 • and 117.6 • [29]. These findings are backed by histological studies [1,2,11,16,19,27,67] that have also identified two distinct populations of sheets in combined data that correlate well with the DTI measurements. Our measured sheet angles for lateral sectors show large intra-and interheart variability, particularly in basal regions (see Figs.…”

Section: Sheet Structurementioning

confidence: 54%

“…The data presented here also offer some possible explanations for the differences in the histologically-derived descriptions of sheet morphology in the literature. Some reports [11,46] describe a single population of sheets that bend through the cardiac wall, while others describe dual populations [1,2,11,16,19,27,67]. Gross variation in sheet structure between individual hearts will result in differing reports, as will local variation in sheet orientation associated with the precise positioning of the regions selected for characterisation.…”

Section: Sheet Structurementioning

confidence: 99%

Reconstruction and Quantification of Diffusion Tensor Imaging-Derived Cardiac Fibre and Sheet Structure in Ventricular Regions used in Studies of Excitation Propagation

Benson

Gilbert

et al. 2008

Math. Model. Nat. Phenom.

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Abstract. Detailed descriptions of cardiac geometry and architecture are necessary for examining and understanding structural changes to the myocardium that are the result of pathologies, for interpreting the results of experimental studies of propagation, and for use as a three-dimensional orthotropically anisotropic model for the computational reconstruction of propagation during arrhythmias. Diffusion tensor imaging (DTI) provides a means to reconstruct fibre and sheet orientation throughout the ventricles. We reconstruct and quantify canine cardiac architecture in selected regions of the left and right ventricular free walls and the inter-ventricular septum. Fibre inclination angle rotates smoothly through the wall in all regions, from positive in the endocardium to negative in the epicardium. However, fibre transverse and sheet angles show large variability in basal regions. Additionally, regions where two populations (positive and negative) of sheet structure merge are identified. From these data, we conclude that a single DTI-derived atlas model of ventricular architecture should be applicable to modelling propagation in wedges from the equatorial and apical left ventricle, and allow comparisons to experimental studies carried out in wedge preparations. However, due to inter-individual variability in basal regions, a library of individual DTI models of basal wedges or of the whole ventricles will be required.

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Transmural left ventricular mechanics underlying torsional recoil during relaxation

Cited by 137 publications

References 46 publications

Left Ventricular Form and Function Revisited: Applied Translational Science to Cardiovascular Ultrasound Imaging

Left Ventricular Form and Function Revisited: Applied Translational Science to Cardiovascular Ultrasound Imaging

Hypertension and heart failure: a dysfunction of systole, diastole or both?

Reconstruction and Quantification of Diffusion Tensor Imaging-Derived Cardiac Fibre and Sheet Structure in Ventricular Regions used in Studies of Excitation Propagation

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