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Since mitral valve (MV) complex (MVC) longitudinally bridges left ventricular (LV) base end and its middle, insufficient MVC longitudinal tissue length (TL) elongation relative to whole LV myocardial longitudinal TL elongation could limit LV-base-longitudinal-TL elongation, leading to predominant LV-base-transverse-TL elongation, constituting LV spherical remodeling. In 30 patients with dilated cardiomyopathy (DCM), 30 with aortic regurgitation (AR), and 30 controls, LV sphericity, LV-apex- or base-transverse- and longitudinal-TL, MVC-longitudinal-TL, and whole-LV-longitudinal-TL were measured by three-dimensional (3D) echocardiography. Ratio of each measure versus mean normal value (i.e., LV-apex-transverse-TL ratio) was considered to express the directional and regional tissue elongation. [LV-base-longitudinal-TL ratio/global-LV-TL ratio] and [MVC-longitudinal-TL ratio/whole-LV-longitudinal-TL ratio] were obtained as the degree of LV-base-longitudinal-TL or MVC-longitudinal-TL elongation relative to the whole LV elongation. LV-apex-transverse-, LV-apex-longitudinal-, and LV-base-transverse-TL ratios were significantly increased (1.27 to 1.42, P < 0.01) in both DCM and AR, while the LV-base-longitudinal-TL ratio was not increased in DCM [1.04 ± 0.19, not significant (ns)] and only modestly increased in AR (1.12 ± 0.21, P < 0.01). Whole-LV-longitudinal-TL ratio was significantly increased in both DCM and AR (1.22 ± 0.18 and 1.20 ± 0.16, P < 0.01), while MVC-longitudinal-TL ratio was not or only modestly increased in both groups (1.07 ± 0.15, ns, and 1.12 ± 0.17, P = 0.02, respectively). Multivariable analysis revealed that LV sphericity was independently related to a reduced [LV-base-longitudinal-TL ratio/global-LV-TL ratio] (standard β = -0.42, P < 0.01), which was further related to a reduced [MVC-longitudinal-TL ratio/whole-LV-longitudinal-TL ratio] (standard β = 0.72, P < 0.01). These are consistent with the hypothesis that relatively less MVC-longitudinal-TL elongation in the process of primary LV myocardial tissue elongation may limit LV-base-longitudinal-TL elongation, contributing to LV spherical remodeling. NEW & NOTEWORTHY Left ventricular (LV) spherical remodeling is associated with poor prognosis and less-effective cardiac performance, which commonly develops in dilated cardiomyopathy. However, its mechanism remains unclear. We hypothesized and subsequently clarified that less mitral valve complex (MVC) tissue longitudinal elongation relative to whole LV myocardial tissue longitudinal elongation is related to disproportionately less LV base longitudinal versus transverse myocardial tissue elongation, constituting spherical remodeling. This study suggests modification of MVC tissue elongation could be potential therapeutic targets.

The mechanism of systolic annular expansion in mitral valve prolapse (MVP) is not clarified. Since annular expansion is systolic outward shift of MV leaflet/chorda tissue complex at superior and outer ends, annular expansion could be related to inward (superior) shift of the complex at another inferior and inner end of the papillary muscle (PM) tip and/or systolic lengthening of the tissue complex, especially MV leaflets.MV annulus systolic expansion, PMs' systolic superior shift, and MV leaflets' systolic lengthening were evaluated by echocardiography with a speckle tracking analysis in 25 normal subjects, 25 subjects with holo-systolic MVP and 20 subjects with late-systolic MVP.PMs' superior shift, MV leaflets' lengthening, MV annular area at the onset of systole and subsequent MV annulus expansion were significantly greater in late-systolic MVP than in holo-systolic MVP (4.6 ± 1.6 versus 1.5 ± 0.7 mm/m 2 , 2.5 ± 1.4 versus 0.6 ± 2.0 mm/m 2 , 6.8 ± 2.5 versus 5.7 ± 1.0 cm 2 /m 2 and 1.6 ± 0.8 versus 0.1 ± 0.5 cm 2 /m 2 , P < 0.001, respectively). Multivariate analysis identified MV leaflets' lengthening and PMs' superior shift as independent factors associated with MV annular expansion.Conclusions: These results suggest that systolic MV annular expansion in MVP is related to abnormal MV leaflets' lengthening and PMs' superior shift.

Objectives: This study sought to examine left atrial (LA) mechanics and the prognostic impact of patients with echocardiographic findings of E/A ratio ≤0.75, deceleration time (DcT) of mitral E-wave >140 ms, but E/ε' ≥10., Background: Traditional diastolic dysfunction (DD) grading system could not classify every patient into a specific group. We considered the group of patients with E/A ≤0.75, DcT >140 ms, but E/ε' ≥10 (proposed new DD grade) as a new group in the DD grading system., Methods: A total of 1,362 consecutive patients were stratified according to the new DD grading system, and the LA volumes, strain, and strain rates were measured by 2-dimensional speckle-tracking analysis. All patients were followed up to determine cardiac death and major adverse cardiac events., Results: An E/A ≤0.75, DcT >140 ms, but E/ε' ≥10 was observed in 227 patients (17%). LA volumes in patients with the new DD grade were between those of the impaired relaxation group and the pseudonormal group. LA strain of the new DD grade was similar to that of the pseudonormal group, whereas LA booster function was preserved as in the impaired relaxation group. During a mean follow-up of 3.0 ± 1.1 years, 25 patients had cardiac death and 61 had major adverse cardiac events. Event-free survival for major adverse cardiac events of the new DD grade was worse than that of the impaired relaxation group but similar to that of the pseudonormal group., Conclusions: The new DD grade is frequently observed and has a prognosis similar to that of the pseudonormal group but significantly worse than that of the impaired relaxation group. However, LA booster function was maintained at the expense of LA volume enlargement. Thus, the new grade should be a distinct entity for routine DD grading., (Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)