ASSESSMENT OF WALL MOTION WITH 3D ECHOCARDIOGRAPHY

在急性心肌梗死（AMI）患者中，室壁运动异常的程度是左室整体功能和预后的重要决定因素。 然而，AMI中LV解剖结构的区域性变形阻碍了用当前可用的方法准确评估LV功能障碍的程度。 实时三维超声心动图（RT-3D echo）是一种提供瞬时容积图像的新技术，可不受限制地显示左室壁运动。本研究的目的是开发和验证一种方法，定量评估室壁运动异常的AMI患者。 为此，36例患者（28例男性;年龄65 ± 14岁），根据临床标准和连续酶升高诊断为首次AMI，在入院24小时内接受RT-3D超声心动图检查。从顶窗获取图像并储存用于盲法离线分析。 通过在Silicone Graphics工作站上追踪室壁运动异常的面积，并以绝对值（cm 2）和总LV内径的百分比表示，实现局部LV功能障碍的定量评估。 肌钙蛋白I峰值水平范围为2.3 - 416 ng/ml（平均值69 ± 88），肌红蛋白峰值水平范围为24 - 2730 ng/ml（平均值507 ± 720）。 室壁运动异常的面积范围为0 - 71 cm 2（平均17+/-14）或占总LV内径的0%-44%（平均13%+/-10%）。 肌钙蛋白I峰值水平与室壁运动异常面积的绝对值（r=0.81; p<0.0001）或占总左室内径的百分比（r=0.79; p<0.0001）之间存在强相关性。 肌红蛋白峰值水平与室壁运动异常面积的绝对值（r=0.51; p=0.003）或占总左室内膜面积的百分比（r=0.54; p<0.002）之间存在显著但较弱的相关性。 因此，在AMI患者中，RT-3D超声心动图可以定量评估室壁运动异常，这与梗死面积的独立测量相关。 因此，这种方法可能有助于确定LV功能障碍的程度，从而有助于对这些患者进行风险分层。

In patients with acute myocardial infarction (AMI), the extent of wall motion abnormality is an important determinant of global left ventricular (LV) function and prognosis. However, the regional distortion of LV anatomy in AMI prevents an accurate assessment of the magnitude of LV dysfunction with currently available methods. Real-time 3-dimensional echocardiography (RT-3D echo) is a novel technique that provides instantaneous volumetric images which permit unrestricted visualization of LV wall motion. The purpose of this study was to develop and validate a methodology for quantitative assessment of wall motion abnormalities in patients with AMI. To this end, 36 patients (28 men; age 65+/-14 years), diagnosed with first AMI based on clinical criteria and serial enzyme elevation, underwent RT-3D echo within 24 hours of admission. Images were acquired from an apical window and stored for blinded off-line analysis. Quantitative assessment of regional LV dysfunction was achieved by tracing the area of wall motion abnormality on a Silicone Graphics workstation and expressed in absolute terms (cm2) and as a percent of total LV endocardium. Peak troponin I levels ranged from 2.3 to 416 ng/ml (mean 69+/-88) and peak myoglobin levels ranged from 24 to 2730 ng/ml (mean 507+/-720). The area of wall motion abnormality ranged from 0 to 71 cm2 (mean 17+/-14) or 0% to 44% of total LV endocardium (mean 13%+/-10%). A strong correlation was observed between peak troponin I levels and area of wall motion abnormality expressed in absolute terms (r=0.81; p<0.0001) or as a percent of total LV endocardium (r=0.79; p<0.0001). A significant but weaker correlation was observed between peak myoglobin levels and area of wall motion abnormality expressed in absolute terms (r=0.51; p=0.003) or as a percent of total LV endocardium (r=0.54; p<0.002). Thus, in patients with AMI, RT-3D echo allows a quantitative assessment of wall motion abnormalities which correlates with independent measures of infarct size. This methodology may therefore be useful to determine the extent of LV dysfunction and thus aid in the risk stratification of these patients.