Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Chiba 260-8670, Japan.
Int J Cardiol. 2012 Jul 26;158(3):423-32. doi: 10.1016/j.ijcard.2011.01.096. Epub 2011 Feb 26.
To distinguish focal fibrotic and non-fibrotic lesions in left-ventricular myocardium (LVM) in hypertrophic-cardiomyopathy (HCM)-subjects, we compared myocardial regional peak-strain values using two-dimensional speckle-tracking transthoracic-echocardiography (TTE) in multislice computed-tomography (CT)-detected fibrotic, non-fibrotic and normal control lesions.
Twenty subjects (10 consecutive HCM-subjects (8-males, mean 63.4-years), 10 healthy controls (5-males, mean 51.5-years)) underwent speckle-tracking TTE (iE-33), and analysis of regional peak-longitudinal (LS) and radial-strain (RS), and corresponding strain rates in each of 17 LVM segments (American-Heart-Association classification). In HCM-subjects, fibrotic lesions were identified by early-phase defective enhancement and late-phase abnormal enhancement by CT (Light-Speed-Ultra-16). Regional peak LS and RS at basal, mid and apical levels were measured in MSCT-detected fibrotic and non-fibrotic LVM lesions.
In 10 HCM subjects, 143 lesions (84.1%) yielded good tracking on TTE. Twenty lesions showed fibrotic changes in 5 subjects by CT. Regional peak-LS and RS absolute values were significantly lower in both fibrotic and non-fibrotic lesions in HCM subjects than in controls at basal, mid, apical levels (all P<0.05). While peak-LS (%) absolute values were significantly lower in fibrotic than non-fibrotic lesions at basal, mid and apical levels (all P<0.05), regional peak-RS absolute values were significantly lower only at mid levels. LS was a more sensitive indicator than the corresponding rate, with better reproducibility.
In HCM, regional peak-LS was significantly lower in fibrotic than non-fibrotic lesions in LVM by CT. Regional peak-LS by speckle-tracking provides useful information noninvasively to distinguish fibrotic from non-fibrotic lesions in LVM in HCM and normal LVM in healthy controls.
通过二维斑点追踪经胸超声心动图（TTE）比较多层螺旋 CT（MSCT）检测的纤维性、非纤维性和正常对照组左心室心肌（LVM）局灶性纤维化和非纤维化病变的心肌节段峰值应变值，以区分肥厚型心肌病（HCM）患者的局灶性纤维化和非纤维化病变。
20 例患者（10 例连续 HCM 患者（8 例男性，平均年龄 63.4 岁），10 例健康对照者（5 例男性，平均年龄 51.5 岁））接受斑点追踪 TTE（iE-33）检查，并对 17 个 LVM 节段（美国心脏协会分类）的局部峰值纵向应变（LS）和径向应变（RS）和相应的应变率进行分析。在 HCM 患者中，通过 CT（Light-Speed-Ultra-16）早期缺损增强和晚期异常增强识别纤维化病变。在 MSCT 检测到的纤维化和非纤维化 LVM 病变中测量基底、中部和心尖水平的局部峰值 LS 和 RS。
在 10 例 HCM 患者中，143 个病变（84.1%）在 TTE 上可获得良好的跟踪。CT 显示 5 例患者中有 20 个病变存在纤维化改变。与对照组相比，HCM 患者的纤维化和非纤维化病变的局部峰值 LS 和 RS 绝对值在基底、中部和心尖水平均显著降低（均 P<0.05）。虽然纤维化病变的峰值 LS（%）绝对值在基底、中部和心尖水平均显著低于非纤维化病变（均 P<0.05），但中部水平的局部峰值 RS 绝对值显著降低。LS 是比相应速度更敏感的指标，具有更好的可重复性。
在 HCM 中，通过 CT 检测的纤维化病变的局灶性 LS 显著低于非纤维化病变。斑点追踪的局部峰值 LS 可提供 LVM 纤维化和非纤维化病变的无创性有用信息，可区分 HCM 中的纤维化和非纤维化病变以及健康对照者中的正常 LVM。
