摘要

BACKGROUND:The dynamic changes of anterior mitral leaflet (AML) curvature are of primary importance for optimal left ventricular filling and emptying but are incompletely characterized.
METHODS AND RESULTS:Sixteen radiopaque markers were sutured to the AML in 11 sheep, and 4-dimensional marker coordinates were acquired with biplane videofluoroscopy. A surface subdivision algorithm was applied to compute the curvature across the AML at midsystole and at maximal valve opening. Septal-lateral (SL) and commissure-commissure (CC) curvature profiles were calculated along the SL AML meridian (M(SL))and CC AML meridian (M(CC)), respectively, with positive curvature being concave toward the left atrium. At midsystole, the M(SL) was concave near the mitral annulus, turned from concave to convex across the belly, and was convex along the free edge. At maximal valve opening, the M(SL) was flat near the annulus, turned from slightly concave to convex across the belly, and flattened toward the free edge. In contrast, the M(CC) was concave near both commissures and convex at the belly at midsystole but convex near both commissures and concave at the belly at maximal valve opening.
CONCLUSIONS:While the SL curvature of the AML along the M(SL) is similar across the belly region at midsystole and early diastole, the CC curvature of the AML along the M(CC) flips, with the belly being convex to the left atrium at midsystole and concave at maximal valve opening. These curvature orientations suggest optimal left ventricular inflow and outflow shapes of the AML and should be preserved during catheter or surgical interventions.

译文

背景: 二尖瓣前叶曲率的动态变化对最佳左心室充盈和排空至关重要,但还没有完全表征。
方法和结果: 对 11 只绵羊的 AML 进行了 16 个不透明标记的缝合,并用双平面视频透视获得了 4 维标记坐标。应用了一种表面细分算法来计算收缩中期和最大气门开度时 AML 的曲率。沿着 SL AML 子午线 (M (SL)) 和 CC AML 子午线 (M (CC)) 计算间隔-侧 (SL) 和连接-连接 (CC) 曲率剖面, 分别向左心房凹进正曲率。在收缩期中期,M (SL) 在二尖瓣环附近呈凹形,在腹部由凹形变为凸形,并沿自由边缘呈凸形。在最大瓣膜开口处,M (SL) 在环附近是平的,从腹部的轻微凹到凸,并向自由边缘变平。相比之下,M (CC) 在两个瓣膜附近呈凹形,在收缩中期呈凸形,但在两个瓣膜附近呈凸形,在最大瓣膜开口处呈凹形。
结论: 虽然 AML 沿 M (SL) 的 SL 曲率在收缩中期和舒张早期的腹部区域相似,但 AML 沿 M (CC) 的 CC 曲率翻转,腹部在收缩中期凸出到左心房,在最大瓣膜开口处凹陷。这些曲率方向提示 AML 的最佳左心室流入和流出形状,应在导管或手术干预期间保留。

cardiac cycle

心血管 心脏机械性活动的周期 临床研究术语
概述  :  

心动周期的概念 心脏机械性活动的周期称为心动周期。心脏每收缩和舒张一次称为一个心动周期。每个心动周期均包括收缩期和舒张期。因此,心动周期可以作为分析心肌机械性活动的基本单元。 1、心动周期中心房、心室活动的顺序和时间关系。如以成人平均心率75次/min算,则每一心动周期为0.8 s。其中两心房收缩期为0.1 s,舒张期约为0.7 s;两心室收缩期为0.3 s,舒张期约为0.5 s。从心室开始舒张到心房开始收缩之前这段时间,心房、心室都处于舒张状态,称为全心舒张

cardiac 英 [ˈkɑːdiæk]  美 [ˈkɑːrdiæk]

释    义   adj. 心脏的,心脏病的;(与)贲门(有关)的

n. (非正式)心脏病患者;强心剂

短    语   cardiac function 心功能,心脏功能

cardiac arrest [医]心搏停止

例    句   Whenever cardiac conditions develop these conditions, weaken or damage your heart, which leads to heart failure.  每当心脏出现这些情况,就会削弱或损害你的心脏,从而导致心力衰竭。

 

Cycle 英 [ˈsaɪkl]  美 [ˈsaɪkl]

释    义   n. 循环;周期;自行车;整套;一段时间

vt. 使循环;使轮转

vi. 循环;骑自行车;轮转

短    语   life cycle 寿命周期;生存期

cell cycle 细胞周期

同根词   adj. cyclical 周期的,循环的

cyclic 环的;循环的;周期的

例    句   You should test for the overload at each point of the cycle. 您应当在周期的每个时刻都测试超负荷。


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