二尖瓣反流口面积的动态变化：慢性动物模型中彩色多普勒超声心动图与基于电磁流量计的方法的比较

Dynamic change in mitral regurgitant orifice area: comparison of color Doppler echocardiographic and electromagnetic flowmeter-based methods in a chronic animal model.

作者信息

Shiota T, Jones M, Teien D E, Yamada I, Passafini A, Ge S, Sahn D J

机构信息

Clinical Care Center for Congenital Heart Disease, Oregon Health Sciences University, Portland, USA.

出版信息

J Am Coll Cardiol. 1995 Aug;26(2):528-36. doi: 10.1016/0735-1097(95)80033-d.

DOI:10.1016/0735-1097(95)80033-d

PMID:7608460

Abstract

OBJECTIVES

The aim of the present study was to investigate dynamic changes in the mitral regurgitant orifice using electromagnetic flow probes and flowmeters and the color Doppler flow convergence method.

BACKGROUND

Methods for determining mitral regurgitant orifice areas have been described using flow convergence imaging with a hemispheric isovelocity surface assumption. However, the shape of flow convergence isovelocity surfaces depends on many factors that change during regurgitation.

METHODS

In seven sheep with surgically created mitral regurgitation, 18 hemodynamic states were studied. The aliasing distances of flow convergence were measured at 10 sequential points using two ranges of aliasing velocities (0.20 to 0.32 and 0.56 to 0.72 m/s), and instantaneous flow rates were calculated using the hemispheric assumption. Instantaneous regurgitant areas were determined from the regurgitant flow rates obtained from both electromagnetic flowmeters and flow convergence divided by the corresponding continuous wave velocities.

RESULTS

The regurgitant orifice sizes obtained using the electromagnetic flow method usually increased to maximal size in early to midsystole and then decreased in late systole. Patterns of dynamic changes in orifice area obtained by flow convergence were not the same as those delineated by the electromagnetic flow method. Time-averaged regurgitant orifice areas obtained by flow convergence using lower aliasing velocities overestimated the areas obtained by the electromagnetic flow method ([mean +/- SD] 0.27 +/- 0.14 vs. 0.12 +/- 0.06 cm2, p < 0.001), whereas flow convergence, using higher aliasing velocities, estimated the reference areas more reliably (0.15 +/- 0.06 cm2).

CONCLUSIONS

The electromagnetic flow method studies uniformly demonstrated dynamic change in mitral regurgitant orifice area and suggested limitations of the flow convergence method.

摘要

目的

本研究旨在使用电磁流量探头和流量计以及彩色多普勒血流会聚法研究二尖瓣反流口的动态变化。

背景

已经描述了使用具有半球形等速表面假设的血流会聚成像来确定二尖瓣反流口面积的方法。然而，血流会聚等速表面的形状取决于反流期间变化的许多因素。

方法

在7只通过手术造成二尖瓣反流的绵羊中，研究了18种血流动力学状态。使用两个不同的混淆速度范围（0.20至0.32和0.56至0.72米/秒）在10个连续点测量血流会聚的混淆距离，并使用半球形假设计算瞬时流速。根据从电磁流量计和血流会聚获得的反流流速除以相应的连续波速度来确定瞬时反流面积。

结果

使用电磁流量法获得的反流口大小通常在收缩早期至中期增加到最大尺寸，然后在收缩晚期减小。通过血流会聚获得的口面积动态变化模式与电磁流量法描绘的模式不同。使用较低混淆速度通过血流会聚获得的时间平均反流口面积高估了通过电磁流量法获得的面积（[平均值±标准差] 0.27±0.14对0.12±0.06平方厘米，p <0.001），而使用较高混淆速度的血流会聚更可靠地估计了参考面积（0.15±0.06平方厘米）。