犬离体心肌应力-应变关系超声印压方法研究

Study on Assessing Stress-Strain Relationship of Canine Isolated Myocardium Using Ultrasound Indentation

目的:探讨超声循环印压检测心肌被动力学属性可行性,为活体检测提供基础。方法:通过循环印压犬离体心室肌,获得印压力和心肌形变实验数据。结果:以准线性粘弹性理论(QLV)模型处理所获得的应力、应变数据,获取左心室心尖和游离壁心肌被动力学属性参数A、B、C、D、E,两者的参数比较无差异(P>0.05)。结论:介入超声循环印压检测心肌被动力学属性是可行的。可望在活体检测不同状态下舒张期心肌被动力学属性,进一步从力学机制层面深入认识舒张性心力衰竭。

Objiective： To investigate the feasibility of assessing myocardial passive mechanical properties using ultrasound cyclic indentation and to lay foundation on assessing directly myocardial passive mechanical properties in vivo. Methods： Isolated canine myocardium was compressed by cyclic loading-unloading using ultrasound indentation apparatus and force of indentation and deformation ofmyocardium were obtained. Results： Mechanical parameters of cardiac apex and free wall such as A ,B,C,D,E were obtained respectively through using the quasi-linear viscoelastic （QLV） theory to process the experimental data. Statistical difference was not found between the two site （P〉 0.05）. Conclusion： Assessing myocardial passive mechanical properties using intervention ultrasound indentation is feasible. This indentation method can be used to assess myocardial passive mechanical properties in vivo in diastole under different status. Further recognition on diastolic heart failure from mechanical mechanism will be obtained.