Background: The aim of this study was to explore the contribution of left ventricular (LV) basal rotation to the mechanism of chronic ischemic mitral regurgitation (MR).
Methods: Fifty-seven patients (52 men; mean age, 68.3 ± 11.8 years) with postinfarction LV dysfunction (defined as an ejection fraction ≤ 45%) were prospectively enrolled. Each invariably had functional MR. To assess MR degree, the effective regurgitant orifice area (EROA) was quantified by echocardiography using the proximal isovelocity surface area method. Furthermore, mitral valve deformation (valve tenting and annular function) and LV global (systolic and diastolic volumes, function, and sphericity) and local remodeling (displacement of papillary muscles, regional strain, and rotation by speckle-tracking) were assessed. The patients were subsequently subdivided into two groups according to the absence (group A) or presence (group B) on transthoracic echocardiography of infarct area in the inferior and/or posterior basal segments.
Results: A larger EROA was found in group B than in group A (P = .034) and in subjects with asymmetric rather than symmetric tethering in either group (P = .036 and P = .040 for groups A and B, respectively). Basal radial (P = .009), circumferential (P = .042), and longitudinal (P = .005) strain and rotation (P = .021) were lower in group B than in group A. There was also a significant inverse correlation between EROA and basal rotation in group B (r = -0.75, P < .001). Furthermore, using multivariate linear regression analysis, we found that the independent determinants of EROA were end-diastolic volume (P < .001) and tenting area (P = .004) in group A and asymmetric tethering (P = .029) and basal rotation (P < .001) in group B.
Conclusions: Impaired basal rotational mechanics occurring after an inferior-posterior myocardial infarction is associated with increased MR.
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http://dx.doi.org/10.1016/j.echo.2013.04.017 | DOI Listing |
Sci Rep
January 2025
Division of Cardiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Myocyte disarray and fibrosis are underlying pathologies of hypertrophic cardiomyopathy (HCM) caused by genetic mutations. However, the extent of their contributions has not been extensively evaluated. In this study, we investigated the effects of genetic mutations on myofiber function and fibrosis patterns in HCM.
View Article and Find Full Text PDFAnat Rec (Hoboken)
December 2024
Biology Department, Northland Pioneer College, Holbrook, Arizona, USA.
Nothronychus graffami was a large therizinosaur represented by a single well-preserved individual from the Turonian Tropic Shale of southern Utah. It is characterized by an enlarged abdomen, small tail, and an extensively pneumatized axial skeleton, and is frequently regarded as herbivorous. Given the overall tail reduction and the development of a wide fused synsacrum with widely spaced acetabulae, it is reconstructed with an anteriorly rotated femur and a displaced resting ground reaction force anterior to the center of mass.
View Article and Find Full Text PDFJ Clin Med
November 2024
Department of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, H-6725 Szeged, Hungary.
While the basal region of the left ventricle (LV) rotates in a clockwise (cw) direction, the apical regions of the LV rotate in a counterclockwise (ccw) direction in healthy circumstances. Although LV rotational mechanics help optimize LV ejection, in some cases, LV twist is missing. This clinical situation, when the LV base and the apex rotate in the same cw or ccw direction, is called LV 'rigid body rotation' (LV-RBR).
View Article and Find Full Text PDFBiomedicines
November 2024
Department of Medicine, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis Street 8, P.O. Box 427, H-6725 Szeged, Hungary.
Introduction: In systole, when the left ventricle (LV) twists, the left atrium (LA) behaves like a reservoir, having a special wall contractility pattern opposite to that of the LV wall. Accordingly, the objective of the present study was to investigate the associations between LV rotational mechanics and LA peak (reservoir) strains as assessed simultaneously by three-dimensional speckle-tracking echocardiography (3DSTE) under healthy conditions.
Methods: In the present study, 157 healthy adults (mean age: 33.
Nat Commun
November 2024
Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.
Motile cilia unify their axonemal orientations (AOs), or beat directions, across epithelia to drive liquid flows. This planar polarity results from cytoskeleton-driven swiveling of basal foot (BF), a basal body (BB) appendage coincident with the AO, in response to regulatory cues. How and when the BF-AO relationship is established, however, are unaddressed.
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