目的 探索心肌带(ventricular myocardial band,VMB)的顺序性收缩功能.方法 家犬10只,开胸手术在VMB各段空间走行路径上置入锡钉,术后以超声心动图确认锡钉位置,2周后C型臂数字减影X线观测锡钉运动,采集锡钉运动图像.结果 心脏的收缩呈现明显的顺序性:VMB各段收缩开始时间差异显著,右室段收缩最早,降段次之(P<0.01),升段最晚;VMB各段收缩终止时间差异也显著,右室段、左室段和降段的收缩终止时间相近(P>0.05,三者时间差异不超过40 ms),升段的收缩终止时间明显晚于降段(P<0.01,滞后约40～80 ms),舒张早期心脏仍然存在主动收缩.结论 为Torrent-Guasp提出的心脏顺序性收缩功能的假说提供了有力证据.%Objective To prove the sequential, contraction of ventricular myocardial band (VMB). Methods Healthy maledogs (n= 10) underwent thoracotomy and tin beads were placed into myocardium based on the spatial trajectory of VMB. At the sec-ond,third week after surgery, the movement of tin beads were recorded by digital subtraction centiography (DSC). Results The fol-lowing sequence of contraction was observed in dog heart. There were significant differences at the initiation moment of contraction ofeach segment in VMB ( P < 0.01 ). Basal loop originated shortening at the earliest stage, descending segment (DS) closely followed,and ascending segment (AS) initiated shortening at latest moment (P<0.01). There were significant differences at the terminationmoment of contraction of each segment in VMB ( P < 0.01 ). DS stops shortening during the rapid filling phase, but AS stopped short-erring at later moment (40-80 ms) than DS. Such, active shortening continues during the period of isovolumetric relaxation. Conclu-sion The study supports Torrent-Guasp's hypothesis on sequential contraction of the heart.
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