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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Feb 26, 2016; 8(2): 146-162
Published online Feb 26, 2016. doi: 10.4330/wjc.v8.i2.146
Mechanical dyssynchrony and deformation imaging in patients with functional mitral regurgitation
Isabella Rosa, Claudia Marini, Stefano Stella, Francesco Ancona, Marco Spartera, Alberto Margonato, Eustachio Agricola
Isabella Rosa, Claudia Marini, Stefano Stella, Francesco Ancona, Marco Spartera, Alberto Margonato, Eustachio Agricola, Echocardiography Laboratory, San Raffaele Hospital, IRCCS, 20132 Milano, Italy
Author contributions: Rosa I and Marini C wrote the manuscript; Stella S, Ancona F and Spartera M collected critically revised the bibliography; Margonato A and Agricola E designed, provided an intellectual contribution and critically revised the manuscript.
Conflict-of-interest statement: The authors declare the absence of any commercial or financial relationships.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Claudia Marini, MD, Echocardiography Laboratory, San Raffaele Hospital, IRCCS, Via Olgettina 60, 20132 Milano, Italy. claudia.marini@outlook.com
Telephone: +39-02-26437313 Fax: +39-02-26437358
Received: July 26, 2015
Peer-review started: July 27, 2015
First decision: September 22, 2015
Revised: November 12, 2015
Accepted: December 7, 2015
Article in press: December 8, 2015
Published online: February 26, 2016
Processing time: 211 Days and 3.5 Hours
Abstract

Chronic functional mitral regurgitation (FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy (DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle (LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy (CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.

Keywords: Mitral regurgitation; Deformation imaging; 3D echocardiography; Mechanical dyssynchrony; Speckle tracking

Core tip: The epidemiologic and prognostic impact of chronic functional mitral regurgitation (FMR) is fully acknowledged. Multiple factors are involved in the pathophysiology of FMR, such as mitral valve remodeling, left ventricle (LV) remodeling and mechanical dyssynchrony. Deformation imaging by 2 dimensional speckle tracking and 3 dimensional echocardiography are the echocardiographic techniques currently used to better characterize LV dyssynchrony. Pharmacologic and cardiac resynchronization therapy is the first line-therapeutic approach to treat FMR. In case of failure of this first therapeutic approach, surgery and percutaneous treatment in high risk patients represent an alternative option.