Han Wei, Xie Ming-xing, Wang Xin-fang, Lü Qing, Wang Jing, Zhang Li, Zhang Jing
Department of Ultrasonography, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology.
Chin Med J (Engl). 2008 Aug 20;121(16):1543-8.
Rotation of the left ventricular (LV) apex to the base, or LV torsion, is related to myocardial contractility and structure and has recently been recognized as a sensitive indicator of cardiac performance, but it has been difficult to measure. The recent development of 2-dimensional (2D) speckle tracking imaging (STI) may provide a powerful means of assessing LV torsion. This study was conducted to evaluate the global and regional LV twist in patients with anterior wall myocardial infarction (AMI) disease before and after revascularization by STI.
2D STI was performed in 35 AMI patients before and one month after revascularization, as well as in 32 normal controls. Left ventricular global and regional rotations were obtained at basal and apical short-axis levels; LV torsion was defined as apical rotation relative to the base. The time sequences were normalized to the percentage of systolic and diastolic duration.
Before revascularization, LV peak regional and global torsion in patients with AMI were significantly reduced as the result of reduced apical and basal rotation relative to those of normal control group (all P < 0.001); most significantly in the anterior and anterior-septal regions (P < 0.001); one month after revascularization, there were significant changes in peak rotation at either the base or apex relative to pre-revascularization values (all P < 0.001). Similarly, peak regional and global LV torsion were increased significantly (all P < 0.001). Global torsion inversely correlated with EDV (r = -0.605, P = 0.028) and ESV (r = -0.638, P = 0.019); and positively correlated with LVEF (r = 0.630, P = 0.021). Tight relations were also found between torsion and LV longitudinal and short axis function.
Systolic torsion was decreased in AMI patients. Revascularization therapy can improve the LV function of the AMI patients. STI has a potential to quantify left ventricular global and segment torsion in patients with AMI, and may make the assessment more available in clinical and research cardiology.
左心室（LV）心尖向心底的旋转，即左心室扭转，与心肌收缩力和结构有关，最近被认为是心脏功能的一个敏感指标，但一直难以测量。二维（2D）斑点追踪成像（STI）的最新发展可能为评估左心室扭转提供一种有力手段。本研究旨在通过STI评估前壁心肌梗死（AMI）患者血运重建前后左心室的整体和局部扭转情况。
对35例AMI患者在血运重建前和后1个月进行2D STI检查，并与32例正常对照者进行比较。在基底和心尖短轴水平获取左心室的整体和局部旋转情况；左心室扭转定义为心尖相对于基底的旋转。时间序列按收缩期和舒张期持续时间的百分比进行归一化。
血运重建前，AMI患者左心室的峰值局部和整体扭转显著降低，这是由于相对于正常对照组，心尖和基底的旋转减少所致（所有P<0.001）；在前壁和前间隔区域最为显著（P<0.001）；血运重建后1个月，基底或心尖的峰值旋转相对于血运重建前的值有显著变化（所有P<0.001）。同样，左心室的峰值局部和整体扭转显著增加（所有P<0.001）。整体扭转与舒张末期容积（EDV）呈负相关（r = -0.605，P = 0.028），与收缩末期容积（ESV）呈负相关（r = -0.638，P = 0.019）；与左心室射血分数（LVEF）呈正相关（r = 0.630，P = 0.021）。还发现扭转与左心室纵向和短轴功能之间存在密切关系。
AMI患者的收缩期扭转降低。血运重建治疗可改善AMI患者的左心室功能。STI有可能量化AMI患者左心室的整体和节段扭转，并且可能使评估在临床和心脏研究中更易于应用。
