Division of Cardiovascular Diseases, Einstein Medical Center, Philadelphia, Pennsylvania.
Division of Cardiovascular Diseases, Einstein Medical Center, Philadelphia, Pennsylvania.
J Am Soc Echocardiogr. 2015 Jul;28(7):786-94. doi: 10.1016/j.echo.2015.03.002. Epub 2015 Mar 30.
The mitral annulus displays complex conformational changes during the cardiac cycle that can now be quantified by three-dimensional echocardiography. Mitral annular calcification (MAC) is increasingly encountered, but its structural and dynamic consequences are largely unexplored. The objective of this study was to describe alterations in mitral annular dimensions and dynamics in patients with MAC.
Transthoracic three-dimensional echocardiography was performed in 43 subjects with MAC and 36 age- and sex-matched normal control subjects. Mitral annular dimensions were quantified, using dedicated software, at six time points (three diastolic, three systolic) during the cardiac cycle.
In diastole, the calcified annulus was larger and flatter than normal, with increased anteroposterior diameter (29.4 ± 0.6 vs 27.8 ± 0.6 mm, P = .046), reduced height (2.8 ± 0.2 vs 3.6 ± 0.2 mm, P = .006), and decreased saddle shape (8.9 ± 0.6% vs 11.4 ± 0.6%, P = .005). In systole, patients with MAC had greater annular area at all time points (P < .05 for each) compared with control subjects, because of reduced contraction along the anteroposterior diameter (P < .001). Saddle shape increased in early systole (from 10.5% to 13.5%, P = .04) in control subjects but not in those with MAC (P = NS). Valvular alterations were also noted; although mitral valve tent length decreased during systole in both groups, decreases were less in patients with MAC (P < .05 for mid- and late systole). For certain parameters (e.g., annular area), changes were confined largely to those patients with moderate to severe MAC (P = .006 vs control subjects, but nonsignificant for patients with mild MAC).
Quantitative three-dimensional echocardiography provides new insights into the dynamic consequences of MAC. This imaging technique demonstrates that the mitral annulus is not made smaller by calcification. However, there is loss of annular contraction, particularly along the anteroposterior diameter, and loss of early systolic folding along the intercommissural diameter. Associated valvular alterations include smaller than usual declines in tenting during systole. These quantitative three-dimensional echocardiographic data provide new insights into the dynamic physiology of the calcified mitral annulus.
在心动周期中，二尖瓣环会发生复杂的构象变化，现在可以通过三维超声心动图来定量分析。二尖瓣环钙化（MAC）的发病率越来越高，但它的结构和动力学后果在很大程度上还未被探索。本研究的目的是描述 MAC 患者二尖瓣环尺寸和动力学的变化。
对 43 例 MAC 患者和 36 例年龄和性别匹配的正常对照组患者进行经胸三维超声心动图检查。使用专用软件在心动周期的六个时间点（三个舒张期，三个收缩期）定量测量二尖瓣环的尺寸。
在舒张期，钙化的瓣环比正常瓣环更大更平，前后径增加（29.4±0.6 毫米比 27.8±0.6 毫米，P=0.046），高度降低（2.8±0.2 毫米比 3.6±0.2 毫米，P=0.006），鞍形减少（8.9±0.6%比 11.4±0.6%，P=0.005）。在收缩期，与对照组相比，所有时间点的 MAC 患者的瓣环面积都更大（每个 P<0.05），这是由于沿前后径的收缩减少（P<0.001）。对照组患者在收缩早期（从 10.5%增加到 13.5%，P=0.04）的鞍形增加，但 MAC 患者则没有（P=NS）。还观察到瓣膜的改变；尽管两组的二尖瓣瓣叶帆长度在收缩期都减少，但 MAC 患者的减少幅度较小（中晚期收缩期 P<0.05）。对于某些参数（例如，瓣环面积），这些变化主要局限于中度至重度 MAC 患者（与对照组相比，P=0.006，但轻度 MAC 患者无统计学意义）。
定量三维超声心动图提供了对 MAC 动态后果的新见解。这种成像技术表明，瓣环不会因钙化而变小。然而，瓣环收缩丧失，特别是沿前后径，沿房室径的早期收缩折叠丧失。相关的瓣膜改变包括收缩期帆的下降幅度通常较小。这些定量三维超声心动图数据为钙化二尖瓣环的动态生理学提供了新的见解。
