Mertens Luc, Ganame Javier, Claus Piet, Goemans Nathalie, Thijs Daisy, Eyskens Bénédicte, Van Laere David, Bijnens Bart, D'hooge Jan, Sutherland George R, Buyse Gunnar
Department of Pediatric Cardiology, University Hospitals Leuven, Leuven, Belgium.
J Am Soc Echocardiogr. 2008 Sep;21(9):1049-54. doi: 10.1016/j.echo.2008.03.001. Epub 2008 Apr 11.
In young patients (aged <12 years) with Duchenne muscular dystrophy (DMD), cardiac systolic function is generally described to be within the normal range. Recent studies have suggested the presence of subclinical dysfunction in these young patients using cardiac magnetic resonance imaging, tissue Doppler measurements, and myocardial velocity gradients. The aim of this study was to further assess regional myocardial function in a young group of patients with DMD using myocardial velocity and deformation imaging.
Thirty-two patients with DMD (mean age, 7.9 years; range, 3-12 years) and 29 age-matched normal controls were studied with echocardiography. Standard echocardiographic measurements of left ventricular (LV) systolic and diastolic function were performed. Myocardial velocity and deformation data, including peak systolic and early and late diastolic myocardial velocities, peak systolic strain rate (SR), and peak systolic strain (epsilon), were calculated in the radial direction in the inferolateral LV wall and in the longitudinal direction in the interventricular septum, the LV anterolateral wall, and the right ventricular (RV) free wall.
Higher heart rates and increased LV end-systolic dimensions were seen in patients with DMD compared with controls. Significant decreases in radial and longitudinal peak systolic SR, peak systolic epsilon, and peak systolic and early diastolic myocardial velocities were found in the LV inferolateral and anterolateral walls in patients with DMD. No significant differences in longitudinal function could be found in the interventricular septum or in the RV free wall.
In young patients with DMD who have global normal systolic function, reductions in systolic deformation parameters as well as reduced early diastolic myocardial velocities can be detected in the anterolateral and inferolateral LV walls. The prognostic significance of these findings warrants further longitudinal follow-up.
在患有杜氏肌营养不良症（DMD）的年轻患者（年龄<12岁）中，心脏收缩功能通常被描述为在正常范围内。最近的研究表明，使用心脏磁共振成像、组织多普勒测量和心肌速度梯度，这些年轻患者存在亚临床功能障碍。本研究的目的是使用心肌速度和变形成像进一步评估一组年轻DMD患者的局部心肌功能。
对32例DMD患者（平均年龄7.9岁；范围3 - 12岁）和29例年龄匹配的正常对照者进行超声心动图检查。进行左心室（LV）收缩和舒张功能的标准超声心动图测量。计算心肌速度和变形数据，包括收缩期峰值、舒张早期和晚期心肌速度、收缩期峰值应变率（SR）和收缩期峰值应变（ε），分别在左心室下外侧壁的径向以及室间隔、左心室前外侧壁和右心室（RV）游离壁的纵向进行测量。
与对照组相比，DMD患者的心率更高，左心室收缩末期内径增加。在DMD患者的左心室下外侧壁和前外侧壁，发现径向和纵向收缩期峰值SR、收缩期峰值ε以及收缩期峰值和舒张早期心肌速度显著降低。在室间隔或右心室游离壁的纵向功能方面未发现显著差异。
在具有整体正常收缩功能的年轻DMD患者中，可检测到左心室前外侧壁和下外侧壁的收缩期变形参数降低以及舒张早期心肌速度降低。这些发现的预后意义值得进一步的纵向随访。
