Department of Surgery 1, School of Veterinary Medicine, Azabu University, Kanagawa, Japan.
BMC Cardiovasc Disord. 2011 May 25;11:23. doi: 10.1186/1471-2261-11-23.
Two-dimensional speckle tracking echocardiography (STE) is a relatively new method to detect regional myocardial dysfunction. To assess left ventricular (LV) regional myocardial dysfunction using STE in Duchenne muscular dystrophy model dogs (CXMD(J)) without overt clinical signs of heart failure.
Six affected dogs, 8 carrier dogs with CXMD(J), and 8 control dogs were used. Conventional echocardiography, systolic and diastolic function by Doppler echocardiography, tissue Doppler imaging (TDI), and strain indices using STE, were assessed and compared among the 3 groups.
Significant differences were seen in body weight, transmitral E wave and E' wave derived from TDI among the 3 groups. Although no significant difference was observed in any global strain indices, in segmental analysis, the peak radial strain rate during early diastole in posterior segment at chordae the tendineae level showed significant differences among the 3 groups.
The myocardial strain rate by STE served to detect the impaired cardiac diastolic function in CXMD(J) without any obvious LV dilation or clinical signs. The radial strain rate may be a useful parameter to detect early myocardial impairment in CXMD(J).
二维斑点追踪超声心动图（STE）是一种检测区域性心肌功能障碍的相对较新的方法。本研究旨在评估无明显心力衰竭临床症状的杜兴肌营养不良症模型犬（CXMD(J)）左心室（LV）区域性心肌功能障碍的 STE 方法。
本研究使用 6 只患病犬、8 只 CXMD(J) 携带者犬和 8 只对照犬。比较三组间常规超声心动图、多普勒超声心动图、组织多普勒成像（TDI）的收缩和舒张功能以及 STE 应变指数。
三组间的体重、经二尖瓣 E 波和 TDI 衍生的 E'波存在显著差异。尽管各整体应变指数无显著差异，但在节段性分析中，腱索水平后间隔早期舒张期的峰值径向应变率存在显著差异。
STE 的心肌应变率可检测无明显 LV 扩张或临床症状的 CXMD(J)的受损心脏舒张功能。径向应变率可能是检测 CXMD(J)早期心肌损伤的有用参数。
