胸部撞击时心脏的动力学响应及心脏损伤

Dynamic Response and Heart Injury During Chest Impact

目的观察胸部受撞击过程中心脏的动力学响应及心脏损伤的病理学特点。方法以不同撞击速度和压缩响应对１１只犬和３４只免进行胸前部撞击，监测胸壁的运动过程，观察心脏损伤特点，运用数学模型分析损伤机制。结果粘性标准与损伤程度密切相关；受撞击后胸壁发生压缩和扩张双向运动；心脏损伤以心内膜出血为主，心脏破裂多发于心室侧壁，光镜观察可见挫伤区心肌纤维断裂；心室侧壁变形大，曲率半径减小，因而出现应力集中，易导致破裂。结论心脏（心室侧壁）高速扩张变形可能是心脏损伤的重要机制。

Objective To investigate the dynamic response of the heart during chestimpact and the CharacteriStics of heart injurieS. Methods Eleven doal and thirty-four rabbitSwere subjected to front thoracic impact with different impact velocities and compressiony^nse. The accelerated move~ of thoracic wall during the imP8ct period was monitored.The pathological examination was done in detail. The dynamic resPOnses and mechanisms ofinjuries were analyzed with mathematical models. Results The injury seventy of heart waswell correlated with the viscous criterion. The thoraciC wall was involved in hi-directionalmovement of compression and expansion, and the injured heart mainly showed spontty orsined hemorrhage in the ventricle endocardium. Light microscopic examination shoWed therupture of the myocardial fibers in the contusion area, and the biomechanical analysis indicatedthat there was a large deformation caned by the Sires concentration on the fat6ral ventriclewall. Conclusions There is a high speed and excessive deformation of heart during the impactperiod, which might be the key mechanism of heart saury.