斑点追踪技术对急性前壁心肌梗死患者左心室扭转及解旋运动的研究

Assessment of left ventricular twisting and untwisting in anterior wall acute myocardial infarction using speckle tracking imaging

目的应用斑点追踪技术（STI）评价急性前壁心肌梗死（AMI）患者左心室扭转及解旋运动的变化。方法38例AMI患者根据左室射血分数（LVEF）分为两组：LVEF正常组（LVEF≥45％，21例）和LVEF减低组（LVEF％45％，17例）。20例正常人作为对照组。取左室心尖和心底短轴二维图像，应用EchoPAC超声工作站进行脱机分析，计算左室扭转角度峰值（Ptw）、收缩末期扭转角度（AVCtw）、等容舒张末期扭转角度（MVOtw）、解旋率（UntwR）、扭转速度峰值（PTV）、扭转速度达峰时间（TPTV）、解旋速度峰值（PUV）和解旋速度达峰时间（TPUV）。结果与对照组及LVEF正常组相比，LVEF减低组Ptw、AVCtw、MVOtw、UntwR明显减低，差异均有统计学意义（P〈0．05）。三组之间PUV、PTV及TPTV差异无统计学意义（P〉0．05）。UntwR与LVEF及左室收缩末期容积有相关性。结论STI技术可准确评价前壁AMI患者左室扭转及解旋。AMI患者LVEF减低组左室扭转角度及UntwR明显减低；左室扭转及解旋影响左室收缩功能。

Objective To examine left ventricular （LV） twisting and untwisting in patients with anterior wall acute myocardial infarction by speckle tracking imaging（STl）. Methods Basal and apical LV short-axis images were acquired in 38 patients with anterior wall myocardial infarction and 20 healthy subjects. Patients were divided into two groups according to global LV systolic function [normal LV ejection fraction （LVEF） group （LVEF≥45%） and abnormal LVEF group （LVEF〈%45%）]. The value of LV rotation at basal and apical levels of each plane were obtained and recorded. Peak twist（Ptw）, twist at aortic valve closure （ AVCtw）, twist at mitral valve opening （ MVOtw）, untwisting rate （UntwR）, peak twist velocity （PTV）, time to peak twist velocity （TPTV）, peak untwisting velocity （PUV）, time to peak untwisting velocity（TPUV） were separately measured. Results Although PTV,PUV and TPTV were not different among the three groups,UntwR were significantly reduced in abnormal LVEF group（ P 〈0.01 ）, and Ptw,AVCtw, MVOtw were also significantly depressed（ P 〈0. 05 ,respectively）. Significant correlation was noted between untwisting rate and LVEF （ r = 0.63, P 〈0. 001） and LV end-systolic volume（ r = 0. 52, P 〈0. 001 ）. Conclusions Left ventrieular twisting and untwisting could be measured by STI. Systolic twisting and diastolic untwisting rate were decreased in accordance with LV systolic dysfunction in anterior wall AMI.