Objective:With biomechanical trial

the feasibility was investigated using the indentation method to assess myocardium viscoelasticity and the change of viscoelasticity after old myocardial infarction was also investigated. Method:The old myocardial infarction moldel was established using ligating the left anterior descending branch under thoracotomy.With the instrument of indentation

creep test was applied to the normal and old infarcted canine ventricular myocardium. Results:The viscoelastic parameteres of normal group:E164±9kPa

E2565±148kPa

E∞57±7kPa

η1.7±0.9×105kPa.s;old infarcted group: E1130±30kPa

E21076±466kPa

113±27kPa

η2.8±1.0×105kPa.s.The difference of parameteres in above two groups is significant in statistics(P<0.05).Conclusion:The results demonstrated that uniaxial indentation was feasible to be used to detect viscoelastic characteristics. After old myocardial infarction

both elastic modulus and viscous damping increased and myocardial compliance descended. Myocardial viscoelasticity under different pathological status in diastole will be studied in vivo using indentation method based on catheter-ultrasound technique.