Hamdy Amal M
Cardiology Department, Al-Zahraa University Hospital, Al-Azhar University, Cairo, Egypt.
Eur J Echocardiogr. 2007 Mar;8(2):102-9. doi: 10.1016/j.euje.2006.02.004. Epub 2006 Mar 24.
Iron overload contributes to cardiac dysfunction in patients with beta thalassemia (Th). Tissue velocity and strain imaging (TVI and SI) might prove useful in early detection of regional myocardial dysfunction in these patients. The aim of this study is to clarify the value of TVI and SI in early detection of regional myocardial dysfunction in thalassemia patients.
This study included two age-matched groups; G1: 27 Th patients and G2: 14 normal subjects. Conventional echo-Doppler measures of LV and RV dimensions and function were obtained. TVI measures included systolic and diastolic myocardial velocities (Sm, Em, Am and Em/Am) of the basal segments of septal wall, lateral LV and RV free walls. Systolic strain values were measured in the same basal segments and included S-septal, S-LV and S-RV. Strain and TVI data were compared in the two groups. Sm and strain values were compared in the different walls (LV, RV and septum) in each group separately. S-LV was lower in G1 than G2 (20.9 +/- 6.8 vs 27.2 +/- 4.3, p < 0.001), while S-septal was higher in G1 than G2 (31.1 +/- 8.3 vs 25.1 +/- 3.8, p < 0.01). TVI measures of diastolic performance of the septal and RV walls were different in G1 compared to G2. Septal-Em was lower, septal-Am was higher and septal-Em/Am was lower in G1 compared to G2. RV-Am was higher and RV-Em/Am was lower in G1 compared to G2. Other SI and TVI measures were not significantly different in G1 from G2. Sm and strain values were lower in the lateral LV wall compared to septal wall in G1 but not in G2, while the corresponding values of the RV wall were higher than those of the septal and LV walls in both groups (G1 and G2).
Thalassemia patients have regional systolic dysfunction in the lateral LV wall and regional diastolic dysfunction in the septal and RV wall. TVI and the newer modality SI are promising tools for quantitative assessment of regional myocardial function. SI seems more capable of early detection of regional myocardial dysfunction.
铁过载会导致β地中海贫血（Th）患者出现心脏功能障碍。组织速度成像和应变成像（TVI和SI）可能有助于早期检测这些患者的局部心肌功能障碍。本研究的目的是阐明TVI和SI在早期检测地中海贫血患者局部心肌功能障碍中的价值。
本研究包括两个年龄匹配的组；G1组：27例Th患者；G2组：14名正常受试者。获取了左心室和右心室大小及功能的传统超声多普勒测量值。TVI测量包括室间隔壁、左心室侧壁和右心室游离壁基底段的收缩期和舒张期心肌速度（Sm、Em、Am和Em/Am）。在相同的基底段测量收缩期应变值，包括室间隔S、左心室S和右心室S。比较两组的应变和TVI数据。分别比较每组不同壁（左心室、右心室和室间隔）的Sm和应变值。G1组的左心室S低于G2组（20.9±6.8对27.2±4.3，p<0.001），而G1组的室间隔S高于G2组（31.1±8.3对25.1±3.8，p<0.01）。与G2组相比，G1组室间隔和右心室壁舒张功能的TVI测量值不同。与G2组相比，G1组的室间隔Em较低，室间隔Am较高，室间隔Em/Am较低。与G2组相比，G1组的右心室Am较高，右心室Em/Am较低。G1组与G2组的其他SI和TVI测量值无显著差异。G1组左心室侧壁的Sm和应变值低于室间隔壁，但G2组无此差异，而两组（G1组和G2组）右心室壁的相应值均高于室间隔壁和左心室壁。
地中海贫血患者左心室侧壁存在局部收缩功能障碍，室间隔壁和右心室壁存在局部舒张功能障碍。TVI和更新的SI模式是定量评估局部心肌功能的有前景的工具。SI似乎更能早期检测局部心肌功能障碍。
