Characterization of 3-dimensional papillary muscle displacement in in vivo ovine models of ischemic/functional mitral regurgitation

The Journal of Thoracic and Cardiovascular Surgery

Mario Walther¹  Tomasz A. Timek²  Wolfgang Bothe³  George T. Daughters⁴  Frederick A. Tibayan⁵ 

[1] Department of Cardiothoracic Surgery, Oregon Health and Science University, Portland, Ore;Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, Calif;Department of Cardiovascular Surgery, Heart Center Freiburg–Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany;Department of Mathematics and Applied Statistics, University of Applied Sciences, Jena, Germany;Division of Cardiothoracic Surgery Spectrum Health, Grand Rapids, Mich

关键词: mitral valve;    mitral regurgitation;    mitral valve repair;    cardiomyopathy;    heart failure;    pathophysiology;    surgery techniques;    cardiac intervention;   

DOI  :  10.1016/j.jtcvs.2018.09.069

学科分类：心脏病和心血管学

来源: Mosby, Inc.

【 摘 要 】

ObjectivePapillary muscle (PM) displacement contributes to ischemic/functional mitral regurgitation (IMR/FMR). The displaced PMs pull the mitral leaflets into the left ventricle (ie, toward the apex) thus hampering leaflet coaptation. Intuitively apical leaflet tethering results from apical PM displacement. The 3-dimensional directions of PM displacement are, however, incompletely characterized.MethodsData from in vivo ovine models of IMR (6-8 weeks of posterolateral infarction, n = 12) and FMR (9-21 days of rapid left ventricular pacing, n = 11) were analyzed. All sheep had radiopaque markers implanted on the anterior and posterior PM (PPM) tips, around the mitral annulus, and on the left ventricular apex. To explore 3-dimensional PM displacement directions, differences in marker coordinates were calculated at end-systole before and during IMR/FMR using a right-handed coordinate system centered on the mitral annular "saddle horn" with the y-axis passing through the apical marker.ResultsNo apical PM displacement was observed during either IMR or FMR. The anterior PM displaced laterally during FMR. Posterolateral PPM displacement was observed during IMR and FMR.ConclusionsExperimental in vivo ovine models suggest posterolateral PPM displacement as a predominant pathomechanism leading to apical leaflet tethering during IMR/FMR.

【 授权许可】

Unknown