Laminar fiber architecture and three-dimensional systolic mechanics in canine ventricular myocardium

1999 ◽  
Vol 276 (2) ◽  
pp. H595-H607 ◽  
Author(s):  
Kevin D. Costa ◽  
Yasuo Takayama ◽  
Andrew D. McCulloch ◽  
James W. Covell
Keyword(s):  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Wall Thickening ◽  
Left Ventricular Myocardium ◽  
Fiber Architecture ◽  
Left Ventricular Free Wall ◽  
Ventricular Mechanics ◽  
Interlaminar Shear ◽  
Canine Ventricular Myocardium

Previous studies suggest that the laminar architecture of left ventricular myocardium may be critical for normal ventricular mechanics. However, systolic three-dimensional deformation of the laminae has never been measured. Therefore, end-systolic finite strains relative to end diastole, from biplane radiography of transmural markers near the apex and base of the anesthetized open-chest canine anterior left ventricular free wall ( n = 6), were referred to three-dimensional laminar microstructural axes reconstructed from histology. Whereas fiber shortening was uniform [−0.07 ± 0.04 (SD)], radial wall thickening increased from base (0.10 ± 0.09) to apex (0.14 ± 0.13). Extension of the laminae transverse to the muscle fibers also increased from base (0.08 ± 0.07) to apex (0.11 ± 0.08), and interlaminar shear changed sign [0.05 ± 0.07 (base) and −0.07 ± 0.09 (apex)], reflecting variations in laminar architecture. Nevertheless, the apex and base were similar in that at each site laminar extension and shear contributed ∼60 and 40%, respectively, of mean transmural thickening. Kinematic considerations suggest that these dual wall-thickening mechanisms may have distinct ultrastructural origins.

scholarly journals Quantitative Assessment of Myocardial Ischemia in Multi-Vessel Coronary Artery Disease by Multimodal Stress Echocardiography with Semi-Supine Bicycle Ergometry

2020 ◽  
Vol 15 (6) ◽  
pp. 813-819
Author(s):  
S. N. Koretskiy ◽  
O. M. Drapkina ◽  
F. B. Shukurov ◽  
D. K. Vasiliev
Keyword(s):  
Stress Echocardiography ◽  
Peak Load ◽  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Cardiovascular Complications ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Myocardial Imaging ◽  
Left Ventricular Myocardium ◽  
Bicycle Ergometry

Stress echocardiography is a modern widely used method of noninvasive diagnosis of coronary heart disease and stratification of the risk of cardiovascular complications. In addition, exercise echocardiography is an important tool to clarify the localization of ischemia and establish a symptomassociated artery for management of patient with known coronary angiography data. This is especially important in multivessel lesions, the presence of an occluded artery or borderline stenosis. Currently, various stress agents are used for stress echocardiography in clinical practice: pharmacological drugs (dobutamine or adenosine), transesophageal or endocardial pacing, treadmill, semi-supine bicycle. To detect signs of ischemia usually used only visual estimation of local contractility in the two-dimensional gray-scale mode. Modern modes of myocardial imaging, such as speckletracking echocardiography or three-dimensional visualization, are practically not used. In the presented clinical case, the possibility of combining standard and modern imaging modes to clarify the localization and quantification of ischemia in multivessel coronary lesions, including chronic artery occlusion, is shown. As a stress agent, a semi-supine bicycle was chosen, the use of which allowed to obtain a qualitative image of the left ventricular myocardium at rest and at peak load, suitable for assessing deformation and threedimensional visualization. Evaluation of left ventricular myocardial deformation by speckle-tracking echocardiography was more accurate than standard diagnosis in detecting signs of ischemia in a patient with multivessel lesions. Three-dimensional imaging was inferior in sensitivity to speckletracking stress echocardiography and, at present, seems to have more research value.

Transmural hematocrit gradient in left ventricular myocardia of rats

1990 ◽  
Vol 259 (2) ◽  
pp. H403-H408 ◽  
Author(s):  
E. Vicaut ◽  
B. I. Levy
Keyword(s):  
Transverse Section ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Left Ventricular Free Wall ◽  
131I Activity ◽  
En Face ◽  
Blood Cell And Plasma

The transmural distribution of tissue hematocrit was determined in rat left ventricular myocardium. Intramyocardial distribution volumes of 99Tc-labeled red blood cells and 131I-labeled albumin were measured in hearts arrested in a relaxed state by KCl or in a contracted state by BaCl2. Hearts were frozen in situ immediately after arrest by bathing in a mixture of liquid nitrogen and isopentane. After excision of the heart, a parallelepipedic portion was cut in a transverse section of the left ventricular free wall and subjected to en face serial sectioning through the thickness of the wall from the epicardium to the endocardium. 99Tc and 131I activity allowed determination of red blood cell and plasma volume and consequently of tissue hematocrit in each section. In both the relaxed and the contracted states of the hearts, a significant decreasing gradient of tissue hematocrit was found from the outer to the inner layers of myocardium. Tissue hematocrit in the subendocardial layers was approximately 70% of its value in the subepicardial layers.

scholarly journals Quantified growth of the human embryonic heart

Biology Open ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. bio057059 ◽  
Author(s):  
Jaeike W. Faber ◽  
Jaco Hagoort ◽  
Antoon F. M. Moorman ◽  
Vincent M. Christoffels ◽  
Bjarke Jensen
Keyword(s):  
Heart Development ◽  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Embryonic Heart ◽  
Growth Patterns ◽  
Right Atrial ◽  
Left Ventricular Myocardium ◽  
Atrioventricular Canal ◽  
The Right

ABSTRACTThe size and growth patterns of the components of the human embryonic heart have remained largely undefined. To provide these data, three-dimensional heart models were generated from immunohistochemically stained sections of ten human embryonic hearts ranging from Carnegie stage 10 to 23. Fifty-eight key structures were annotated and volumetrically assessed. Sizes of the septal foramina and atrioventricular canal opening were also measured. The heart grows exponentially throughout embryonic development. There was consistently less left than right atrial myocardium, and less right than left ventricular myocardium. We observed a later onset of trabeculation in the left atrium compared to the right. Morphometry showed that the rightward expansion of the atrioventricular canal starts in week 5. The septal foramina are less than 0.1 mm2 and are, therefore, much smaller than postnatal septal defects. This chronological, graphical atlas of the growth patterns of cardiac components in the human embryo provides quantified references for normal heart development. Thereby, this atlas may support early detection of cardiac malformations in the foetus.This article has an associated First Person interview with the first author of the paper.

Impact of acute and enduring volume overload on mechanotransduction and cytoskeletal integrity of canine left ventricular myocardium

2007 ◽  
Vol 292 (5) ◽  
pp. H2324-H2332 ◽  
Author(s):  
Dirk W. Donker ◽  
Jos G. Maessen ◽  
Fons Verheyen ◽  
Frans C. Ramaekers ◽  
Roel L. H. M. G. Spätjens ◽  
...  
Keyword(s):  
Protein Expression ◽  
Volume Overload ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Mechanical Stimuli ◽  
Hypertrophic Growth ◽  
Lim Protein ◽  
Ventricular Mechanics

It is poorly understood how mechanical stimuli influence in vivo myocardial remodeling during chronic hemodynamic overload. Combined quantitation of ventricular mechanics and expression of key proteins involved in mechanotransduction can improve fundamental understanding. Adult anesthetized dogs ( n = 20) were studied at sinus rhythm (SR) and 0, 3, 10, and 35 days of complete atrioventricular block (AVB). Serial left ventricular (LV) myofiber mechanics were measured. Repeated LV biopsies were analyzed for mRNA and/or protein expression of β1D-integrin, melusin, Akt, GSK3β, muscle LIM protein (MLP), four-and-a-half LIM protein 2 (fhl2), desmin, and calpain. Upon AVB, increased ejection strain (0.29 ± 0.01 vs. 0.13 ± 0.02, SR) and end-diastolic stress (4.8 ± 1.1 vs. 2.7 ± 0.4 kPa) dominated mechanical changes. Brain natriuretic peptide plasma levels were correspondingly high (33 ± 4 vs. 19 ± 1 pg/ml, SR). β1D-Integrin protein expression increased chronically after AVB. Melusin was temporarily overexpressed (+33 ± 9%, 3 days AVB vs. SR), followed by elevated ratios of phosphorylated (P)-Akt to Akt and P-GSK3β to GSK3β (+26 ± 6% and +30 ± 8% at 10 days AVB vs. SR). These changes corresponded to peak hypertrophic growth at 3 to 10 days. MLP increased gradually to maxima at chronic AVB (+36 ± 7%). In contrast, fhl2 (−22 ± 3%, 3 days) and desmin (−30 ± 9%, 10 days AVB) transiently declined but recovered at chronic AVB. Calpain protein expression remained unaltered. In conclusion, volume overload after AVB causes a transient compromise of cytoskeletal integrity based, at least partly, on transcriptional downregulation. Subsequent cytoskeletal reorganization coincides with the upregulation of melusin, P-Akt, P-GSK3β, and MLP, indicating a strong drive to compensated hypertrophy.

Three-dimensional contour detection of left ventricular myocardium using elastic surfaces

1999 ◽  
Vol 26 (3) ◽  
pp. 201-207 ◽  
Author(s):  
Stefan Biedenstein ◽  
Michael Schäfers ◽  
Lars Stegger ◽  
Torsten Kuwert ◽  
Otmar Schober
Keyword(s):  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Contour Detection ◽  
Left Ventricular Myocardium ◽  
Elastic Surfaces

scholarly journals Three-dimensional architecture of the left ventricular myocardium

2006 ◽  
Vol 288A (6) ◽  
pp. 565-578 ◽  
Author(s):  
Paul P. Lunkenheimer ◽  
Klaus Redmann ◽  
Natalie Kling ◽  
Xiaoji Jiang ◽  
Kai Rothaus ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium

scholarly journals Isolated left ventricular apical hypoplasia with myocardial non-compaction: a case report

2019 ◽  
Vol 4 (1) ◽  
pp. 1-6
Author(s):  
Viktoria I Skidan ◽  
Tatiana Kuznetsova ◽  
Elena N Pavlyukova ◽  
Galina P Nartsissova
Keyword(s):  
New York ◽  
Sinus Rhythm ◽  
Contractile Function ◽  
Systolic Function ◽  
Three Dimensional ◽  
Heart Association ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Fatty Tissue

Abstract Background Isolated left ventricular apical hypoplasia (ILVAH) is a rare congenital cardiac abnormality, which might result in severe symptomatic heart failure (HF) with pulmonary hypertension, atrial fibrillation (AF), or malignant ventricular tachycardia in adults. Case summary A 32-years-old man presented with exertional dyspnoea New York Heart Association Class II and persistent AF. Echocardiography and cardiac magnetic resonance showed the presence of (i) spherical remodelling of the left ventricle (LV) with impaired contractile function (three-dimensional ejection fraction, EF 32%); (ii) substitution of apical myocardium by fatty tissue; (iii) abnormal origin of a papillary muscle network; and (iv) an elongated right ventricle, compatible with ILVAH. In addition, non-compacted endomyocardial layer of the LV was observed. Because of a high risk of sudden cardiac death in symptomatic HF patients with reduced EF, an implantable cardioverter-defibrillator was placed which followed by pulmonary vein isolation. After the procedures and restoration of sinus rhythm, the patient demonstrated improvement in HF symptoms and exercise tolerance. This was accompanied by an enhancement of left and right ventricular systolic function by echocardiography. At 6-month, 1, and 2-year follow-up the clinical conditions of the patient and echocardiographic findings remained stable. Discussion A rare combination of ILVAH and left ventricular myocardium non-compaction was observed in this young adult who presented with symptomatic HF and persistent AF. The use of consecutive invasive cardiac procedures leads to restoration of sinus rhythm, the improvement of myocardial contractility and clinical manifestation of HF.

scholarly journals Noninvasive measurements of transmural myocardial metabolites using 3-D 31P NMR spectroscopy

2001 ◽  
Vol 280 (1) ◽  
pp. H489-H497 ◽  
Author(s):  
Yong K. Cho ◽  
Hellmut Merkle ◽  
Jianyi Zhang ◽  
Nikolaos V. Tsekos ◽  
Robert J. Bache ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
31P Nmr Spectroscopy ◽  
Phase Encoding ◽  
Noninvasive Measurements ◽  
Magnetic Field Magnitude

A completely noninvasive three-dimensional (3-D) static magnetic field magnitude spatially localized 31P spectroscopy technique has been developed and applied to study the in vivo canine myocardium at 9.4 T. The technique incorporates both Fourier series windows and selective Fourier transform methods utilizing all three orthogonal gradients for 3-D phase encoding. The number of data acquisitions for each phase-encoding step was weighted according to the Fourier coefficients to define cylindrical voxels. Spatially localized 31P spectra can be generated for voxels of desired location within the field of view as a postprocessing step. The quality of localization was first demonstrated by using a three-compartment phantom. The technique was then applied to in vivo canine models and yielded 31P cardiac spectra with an excellent signal-to-noise ratio. The in vivo validation experiments, using an implanted 2-phosphoenolpyruvate-containing marker, demonstrated that the technique is capable of measuring at least two transmural layers of left ventricular myocardium representing the subepicardium and subendocardium.

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