超声物理因素对心室肌消融效果的影响

目的 探讨超声物理因素对其损伤灶的影响。方法 使用自行研制的超声导管消融系统，在犬离体右室或左室游离壁热动力学模型上进行超声心室肌消融，并与射频消融比较。结果 电功率与超声损伤灶深度线性相关损伤面积与辐照时间有正相关关系。电功率是超声消融损伤深度较理想的预测因素，能量是描述损伤面积较好的物理量，换能器／组织接触压与损伤灶大小无明显关系，超声损伤灶的远大于射频损伤灶的深度，结论 与射频消融相比，超声

An experimental study of the influence of various factors ofultrasound on the myocardial lesions in an in vitro thermodynamic model

Objective To investigate the influence of various physical factors on the size of the resultant lesion during ultrasound catheter ablation. Methods An ultrasound catheter ablation system was constructed and a thermodynamic model in isolated perfused and superfused canine right or left free wall was established. Different levels of electrical power and acoustic time were adopted and the size of the resulting lesions was measured to observe the dose-response relationship. Lesions resulted by using different levels of power and duration of radiofrequency energy delivery were also observed for comparison. Results There was a linear relationship between the increasing electrical power and the depth of lesion. There were also positive relationships between the lesion area and the sonication time. Electrical power was a better predictor of the lesion depth, while energy is a better physical variable to describe the lesion area. Transducer-tissue contact pressure has no significant effect on the lesion size. The lesion depth of ultrasound ablation was much greater than that of the radiofrequency ablation. Conclusion In comparison with radiofrequency, ultrasound should be able to create the deeper lesions that should be beneficial for the treatment of ventricular tachycardia after myocardial infarction.