REGULATION OF THE AORTIC-VALVE OPENING - IN-VIVO DYNAMIC MEASUREMENT OF AORTIC-VALVE ORIFICE AREA
REGULATION OF THE AORTIC-VALVE OPENING - IN-VIVO DYNAMIC MEASUREMENT OF AORTIC-VALVE ORIFICE AREA
复制标题
DOI：
10.1016/s0022-5223(95)70246-6
复制
发表时间：
1995-08-01
影响因子：
6
通讯作者：
IMAI, Y
中科院分区：
文献类型：
--
作者：
HIGASHIDATE, M;TAMIYA, K;IMAI, Y
用一种新型的电磁感应测量系统对麻醉犬的主动脉瓣口面积进行了动态测量，该系统可以实时测量心脏跳动中的瓣口面积，在主动脉压力开始升高之前，主动脉瓣就已经开放，没有检测到顺行的主动脉血流，最大开放面积在血流峰值前平均20~35ms达到最大开放面积，最大开放面积不仅受主动脉血流的影响，而且还受主动脉压力的影响，从而产生主动脉根部扩张，主动脉瓣口面积的下降曲线(对应于瓣膜关闭)由两个阶段组成：初期减小和后期减小。主动脉瓣瓣口面积开始下降(4.1 cm(2)/s)慢于晚期(28.5 cm(2)/s)，在开始缓慢关闭时，主动脉瓣关闭面积从最大值的40%下降到最大值的40%。这些测量结果表明：(1)主动脉瓣开始缓慢关闭是由主动脉根部扩张产生的瓣叶张力引起的(瓣叶张力使主动脉瓣瓣口呈三角形)；(2)晚期快速关闭是由于血液回流到Valsalva窦引起的。因此，由于主动脉内压引起的瓣叶扩张在主动脉瓣的开启和关闭以及主动脉血供缺陷中起着重要的作用。
Aortic valve orifice area was dynamically measured in anesthetized dogs with a new measuring system involving electromagnetic induction, This system permits us real-time measurement of the valve orifice area in beating hearts in situ, The aortic valve was already open before aortic pressure started to increase without detectable antegrade aortic flow, Maximum opening area was achieved while flow was still accelerating at a mean of 20 to 35 msec before peak blood flow, Maximum opening area was affected by not only aortic blood how but also aortic pressure, which produced aortic root expansion, The aortic valve orifice area's decreasing curve (corresponding to valve closure) was composed of two phases: the initial decrease and late decrease. The initial decrease in aortic valve orifice area was slower (4.1 cm(2)/sec) than the late decrease (28.5 cm(2)/sec), Aortic valve orifice area was reduced from maximum to 40% of maximum (in a triangular open position) during the initial slow closing, These measurements showed that (1) initial slow closure of the aortic valve is evoked by leaflet tension which is produced by the aortic root expansion (the leaflet tension tended to make the shape of the aortic orifice triangular) and (2) late rapid closure is induced by backflo w of blood into the sinus of Valsalva. Thus, cusp expansion owing to intraaortic pressure plays an important role in the opening and closing of the aortic valve and aortic blood flaw.