Mitral valve motion assessed by high-speed video camera in isolated swine heart.
Mitral valve motion assessed by high-speed video camera in isolated swine heart.
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DOI：
10.1016/j.ejcts.2006.07.021
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
Shunei Saito;Y. Araki;A. Usui;T. Akita;H. Oshima;J. Yokote;Y. Ueda
中科院分区：
文献类型：
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作者：
Shunei Saito;Y. Araki;A. Usui;T. Akita;H. Oshima;J. Yokote;Y. Ueda
目的：我们最近报道了我们的分离且工作的猪心脏模型，该模型通过高速数字摄像机系统精确检查瓣膜运动。使用这种方式，本研究的目的是 (1) 描绘整个心动周期中二尖瓣叶、腱索和瓣环的运动，以及 (2) 阐明负荷条件的变化对小叶偏移的影响。方法：通过内窥镜以每秒 250 帧的速度记录图像来观察 5 个离体且工作的猪心脏的瓣膜运动。使用改良的 Krebs-Ringer 溶液作为唯一的灌注液。这些图像是在再灌注 30 分钟后在心脏中获得的，将左心房压力更改为 4、8 和 12 mmHg。结果：通过将整个序列分为五个阶段：“脱离”、“E 偏移”、“分离”、“A 偏移”和“接合”，二尖瓣在舒张期附近的运动被认为可以很好地理解。初始分离发生在二尖瓣中央尖端的两侧。传单。在打开和关闭期间，前缘始终遵循粗糙区域的中间部分。 “支柱”二阶和弦在整个心动周期中保持张力，并充当其他分支和弦的旋转轴。一阶和弦在打开过程中失去张力，表明它们主要参与瓣膜功能。环形收缩与心房收缩同时发生。预紧力的增加使得等容舒张和收缩时间更短。瓣叶在快速充盈阶段打开得更快，而在心房充盈阶段则需要更多时间打开和关闭。结论：本研究揭示了二尖瓣小叶、腱索和瓣环的整体运动，以及改变前负荷的影响。
Objective: We have recently reported our isolated and working swine heart model that examines the valve motion precisely by a high-speed digital video camera system. Using this modality, the present study aimed (1) to delineate the motion of the mitral leaflets, chords and annulus throughout the cardiac cycle, and (2) to elucidate the influence of alterations in loading conditions on leaflet excursion.Methods: The valve motion of five isolated and working swine hearts was observed by an endoscope recording the images at 250 frames per second. Modified Krebs–Ringer solution was used as the sole perfusate. The images were obtained in hearts 30 min after reperfusion, changing the left atrial pressure as 4, 8, and 12 mmHg.Results: The motion of the mitral valve in the vicinity of diastole was considered to be well understood by dividing the entire sequence into five stages: ‘decoaptation,’ ‘E excursion,’ ‘diastasis,’ ‘A excursion,’ and ‘coaptation.’ Initial separation occurred at both sides of the central tips of the leaflets. The leading edges always followed the mid-portion of the rough zone during opening and closing. The ‘strut’ second-order chords retained their tension throughout the cardiac cycle and played the role as rotary shafts of the other branching chords. The first-order chords lost their tension during opening, suggesting they mainly are involved in valve competence. Annular constriction occurred coincident with atrial contraction. An increase in preload made the isovolumic relaxation and contraction times shorter. The leaflets opened faster in the rapid-filling phase, whereas they required more time for opening and closing in the atrial-filling phase.Conclusions: The present study revealed the integrated movement of the mitral leaflets, chords and annulus, as well as the impact of altered preload.