钝力冲击后心脏组织形态学变化的实验研究

本研究用自制机械式弹性拉力打击器以６．７ｍ／ｓ、８．０ｍ／ｓ、９．１ｍ／ｓ及１０．０ｍ／ｓ速度冲击大胸骨心前区，然后采用多种组织学染色及透射电镜技术对心脏组织形态学变化进行了观察。结果表明：①以６．７ｍ／ｓ及８．０ｍ／ｓ速度冲击后心脏宏观未见有明显改变，微观可见心肌波浪变。电镜下可见肌原纤维肌节收缩，Ｉ带消失或轻度Ｉ带增宽乃至肌原纤维断裂。②以９．１ｍ／ｓ及１０．０ｍ／ｓ速度冲击后宏观可见心脏挫伤，微观心肌挫伤改变明显，实验观察６０ｍｉｎ内心肌血管内皮损伤处已有血小板粘附集聚甚至血栓形成，心肌超微结构损害严重。③同一心脏可有多部位损伤，且损伤程度不均一。本研究进一步表明钝力性心脏外伤中．虽然无宏观损伤所见，其微观，特别是超微结构可有损害。

A Pathological Study on Cardiac Morphologic Changes due to Blunt Force Impact at Different Velocities

The sternum precordial zone of dogs was impacted at velocities of 6. 7m/s, 8. 0m/s, 9. 1m/s and 10.0m/s with mechanical elastic-cord propelled impactor. Morphological changes were studied by histochemistry and electron microscopy. The results showed that: (1) No gross anatomic lesions but myocardial fiber waviness under microscope was detected. In ultrastructure myofibril contraction hand, slightly widened I band or even torn myofibrils were observed when impact was delivered at velocity of 6. 7m/s and 8. 0m/s. (2) At impact velocity of 9.1m/s and 10. 0m/s macroscopic cardiac contusions in associated with evident microscopic lesions were demonstrated. Platelet aggregation or thrombus formation occurred at the site of injured vascular endothelia. More severe ultrastructural damage was found. (3) There might be multiple lesions that revealed in various degrees of injuries in a traumatized heart. It is further demonstrated that lesions in microstructure, especially in ul trastructure could be identified without gross anatomic find ings in blunt cardiac trauma.