二维超声斑点追踪显像技术评价心力衰竭兔左心室心肌力学改变

Evaluation of changes of left ventricular myocardial mechanics by two-dimensional speckle tracking imaging in rabbits with heart failure

目的探讨二维超声斑点追踪显像(2DSTI)评价心力衰竭(HF)兔左心室心肌力学改变的价值。方法 27只新西兰兔建立HF模型(A组)后分为轻度CF组[A1组,左心室射血分数(LVEF)≥45%,16只]和重度CF组(A2组,LVEF<45%,11只),另取10只新西兰兔为对照(B组)。于术前和术后4、8、12周行2DSTI检查,计算左室短轴面积变化率(FAC),分析左心室基底部、心尖部旋转运动及左室整体扭转和解旋运动。ELISA法测定血浆脑钠肽(BNP),Masson染色行心肌病理学观察。结果与B组比较,A组术后心底旋转角度、心尖旋转角度、左心室扭转峰值(Ptw)、峰值扭转速度(PTV)、解旋速度峰值(PUTV)均下降,PUTV达峰时间(t-PUTV)延迟(P<0.01或P<0.05)。A1、A2组术后血浆BNP均随时间延长进行性增加(P<0.01)。Ptw与LVEF、FAC和PTV呈正相关(P<0.05),与t-PTV和BNP呈负相关(P<0.05)。PUTV与t-PUTV、E/Em和BNP呈正相关,与Em/Am呈负相关(P<0.05)。结论应用2DSTI技术可定量评价HF兔左心室心肌力学改变。

Objective To investigate the value of two-dimensional speckle tracking imaging （2DSTI） in evaluating the changes of left ventricular myocardial mechanics in rabbits with heart failure（HF）. Methods HF models were established in 27 New Zealand rabbits（group A） ,which Were divided into subgroups of A1 [（with mild HF, left ventricular ejection fraetion（LVEF）≥45%, 16 rabbits] and A2（with severe HF,LVEF〈45%, 11 rabbits）. Ten New Zealand rabbits were taken as blank controls（group B）. Left ventricular base and apex, left ventricular twisting and untwisting were analyzed by 2DSTI before and in the 4th, 8th and 12th week after surgery. The left ventrieular short axis area change rate（FAC） was calculated. Plasma brain natriuretie peptide（BNP） was detected by ELISA. Myocardial pathological pattern was observed by Masson staining. Results Compared with group B, the rot-base, rot-apex, peak twist（Ptw）, peak twisting velocity（PTV）, and peak untwisting veloeity（PUTV） were decreased, but the time to PUTV（t-PUTV） was prolonged in group A after surgery（P〈0. 01 or P〈0. 05）. Plasma levels of BNP in groups of A1 and A2 were increased as the time went on （P〈0. 01）. Ptw was positively correlated to LVEF, FAC and PTV, but negatively correlated to t-PTV and BNP（P〈0. 05）. PUTV was positively correlated to t-PUTV, E/Era and BNP, but negatively to Em/Am（P〈0. 05）. Conclusion 2DSTI can quantitatively evaluate the changes of left ventricular myocardial mechanics in rabbits with HF.