Division of Cardiovascular Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan.
Circ Cardiovasc Imaging. 2010 Nov;3(6):638-46. doi: 10.1161/CIRCIMAGING.110.937300. Epub 2010 Sep 8.
left ventricular (LV) remodeling can increase tethering force to mitral valve and functional mitral regurgitation (FMR). Because the relationship between FMR and regional myocardial function has not been quantitatively evaluated, we conducted a quantitative investigation of this association.
the effective regurgitant orifice (ERO) of FMR in 51 patients with depressed LV ejection fraction (32±9%) secondary to ischemic or nonischemic cardiomyopathy was compared with mitral deformation (valve and annulus), global LV remodeling (volume indices, function, and sphericity), and regional myocardial contractile function, as assessed by longitudinal peak systolic strain rate (Ssr) in LV anterior, anteroseptal, inferoseptal, inferior, inferolateral, and anterolateral segments at rest. Low-dose dobutamine (10 μg/kg per minute)-induced changes in ERO were compared with changes in the variables. Multivariable analysis identified the predictors of ERO at rest as mitral valvular tenting (β=0.062; P<0.001), Ssr in the inferior segment (inferior Ssr) (β=-0.178; P<0.001), and LV sphericity (β=0.414; P=0.001) and the predictors of valvular tenting at rest as inferior Ssr (β=-1.680; P<0.001), LV end-systolic volume index (β=0.022; P=0.001), and LV sphericity (β=3.886; P=0.012). Furthermore, dobutamine-induced reduction in ERO was predicted by reduction in valvular tenting (β=0.087; P<0.001) and increase in inferior Ssr (β=-0.082; P<0.001), and dobutamine-induced reduction in valvular tenting was predicted by increase in inferior Ssr (β=-0.860; P<0.001).
inferior regional myocardial dysfunction was quantitatively associated with mitral valvular tenting and FMR. Moreover, improvement with dobutamine of inferior myocardial contractile function attenuated valvular tenting and FMR. Inferior myocardial contractile function can affect the configuration of the mitral apparatus and predict FMR severity.
左心室（LV）重构会增加二尖瓣的牵拉力，并导致功能性二尖瓣反流（FMR）。由于尚未对 FMR 与局部心肌功能之间的关系进行定量评估，因此我们对此相关性进行了定量研究。
我们比较了 51 例因缺血性或非缺血性心肌病导致左心室射血分数降低（32±9%）的患者的 FMR 的有效反流口（ERO）与二尖瓣变形（瓣叶和瓣环）、整体 LV 重构（容量指数、功能和球形度）以及局部心肌收缩功能，后者通过静息时 LV 前壁、前间隔、下间隔、下壁、下侧壁和前侧壁的纵向收缩期峰值应变率（Ssr）进行评估。比较了多巴酚丁胺（10μg/kg/min）低剂量诱导的 ERO 变化与变量变化。多变量分析确定静息时 ERO 的预测因子为二尖瓣瓣叶幕状运动（β=0.062；P<0.001）、下壁节段的 Ssr（下壁 Ssr）（β=-0.178；P<0.001）和 LV 球形度（β=0.414；P=0.001），静息时瓣叶幕状运动的预测因子为下壁 Ssr（β=-1.680；P<0.001）、LV 收缩末期容积指数（β=0.022；P=0.001）和 LV 球形度（β=3.886；P=0.012）。此外，ERO 的多巴酚丁胺诱导降低可由瓣叶幕状运动的降低（β=0.087；P<0.001）和下壁 Ssr 的增加（β=-0.082；P<0.001）预测，而瓣叶幕状运动的多巴酚丁胺诱导降低可由下壁 Ssr 的增加（β=-0.860；P<0.001）预测。
下壁区域心肌功能障碍与二尖瓣瓣叶幕状运动和 FMR 呈定量相关。此外，多巴酚丁胺改善下壁心肌收缩功能可减轻瓣叶幕状运动和 FMR。下壁心肌收缩功能会影响二尖瓣装置的形态并预测 FMR 的严重程度。
