Multimodal image analysis and subvalvular dynamics in ischemic mitral regurgitation.
JTCVS Open
; 5: 48-60, 2021 Mar.
Article
em En
| MEDLINE
| ID: mdl-36003177
Background: The exact geometric pathogenesis of leaflet tethering in ischemic mitral regurgitation (IMR) and the relative contribution of each component of the mitral valve complex (MVC) remain largely unknown. In this study, we sought to further elucidate mitral valve (MV) leaflet remodeling and papillary muscle dynamics in an ovine model of IMR with magnetic resonance imaging (MRI) and 3-dimensional echocardiography (3DE). Methods: Multimodal imaging combining 3DE and MRI was used to analyze the MVC at baseline, 30 minutes post-myocardial infarction (MI), and 12 weeks post-MI in ovine IMR models. Advanced 3D imaging software was used to trace the MVC from each modality, and the tracings were verified against resected specimens. Results: 3DE MV remodeling was regionally heterogenous and observed primarily in the anterior leaflet, with significant increases in surface area, especially in A2 and A3. The posterior leaflet was significantly shortened in P2 and P3. Mean posteromedial papillary muscle (PMPM) volume was decreased from 1.9 ± 0.2 cm3 at baseline to 0.9 ± 0.3 cm3 at 12 weeks post-MI (P < .05). At 12 weeks post-MI, the PMPM was predominately displaced horizontally and outward along the intercommissural axis with minor apical displacement. The subvalvular contribution to tethering is a combination of unilateral movement, outward displacement, and degeneration of the PMPM. These findings have led to a proposed new framework for characterizing PMPM dynamics in IMR. Conclusions: This study provides new insights into the complex interrelated and regionally heterogenous valvular and subvalvular mechanisms involved in the geometric pathogenesis of IMR tethering.
2D, two-dimensional; 3D echocardiography; 3DE, 3-dimensional echocardiography; AC, anterior commissure; ALPM, anterolateral papillary muscle; ANC, annular center; BNM, bilateral noncongruent movement; IMR, ischemic mitral regurgitation; LV, left ventricular; MI, myocardial infarction; MV, mitral valve; MVC, mitral valve complex; PM, papillary muscle; PMPM, posteromedial papillary muscle; image analysis; ischemic mitral regurgitation; magnetic resonance imaging; multimodal imaging
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
JTCVS Open
Ano de publicação:
2021
Tipo de documento:
Article
País de publicação:
Holanda