Impact of left ventricular outflow tract flow acceleration on aortic valve area calculation in patients with aortic stenosis

IF 3.2 Q2 CARDIAC & CARDIOVASCULAR SYSTEMS

Echo Research and Practice Pub Date : 2019-10-07 DOI:10.1530/ERP-19-0017

A. Ahmed, R. Matyal, Feroze Mahmood, R. Feng, Graham B Berry, Scott Gilleland, K. Khabbaz

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引用次数: 1

Abstract

Objective Due to its circular shape, the area of the proximal left ventricular tract (PLVOT) adjacent to aortic valve can be derived from a single linear diameter. This is also the location of flow acceleration (FA) during systole, and pulse wave Doppler (PWD) sample volume in the PLVOT can lead to overestimation of velocity (V1) and the aortic valve area (AVA). Therefore, it is recommended to derive V1 from a region of laminar flow in the elliptical shaped distal LVOT (away from the annulus). Besides being inconsistent with the assumptions of continuity equation (CE), spatial difference in the location of flow and area measurement can result in inaccurate AVA calculation. We evaluated the impact of FA in the PLVOT on the accuracy of AVA by continuity equation (CE) in patients with aortic stenosis (AS). Methods CE-based AVA calculations were performed in patients with AS once with PWD-derived velocity time integral (VTI) in the distal LVOT (VTILVOT) and then in the PLVOT to obtain a FA velocity profile (FA-VTILVOT) for each patient. A paired sample t-test (P < 0.05) was conducted to compare the impact of FA-VTILVOT and VTILVOT on the calculation of AVA. Result There were 46 patients in the study. There was a 30.3% increase in the peak FA-VTILVOT as compared to the peak VTILVOT and AVA obtained by FA-VTILVOT was 29.1% higher than obtained by VTILVOT. Conclusion Accuracy of AVA can be significantly impacted by FA in the PLVOT. LVOT area should be measured with 3D imaging in the distal LVOT.

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主动脉瓣狭窄患者左心室流出道血流加速对主动脉瓣面积计算的影响

目的主动脉瓣附近的左心室近端区（PLVOT）由于其圆形，可以由单个线性直径得出。这也是收缩期血流加速度（FA）的位置，PLVOT中的脉搏波多普勒（PWD）样本量可能导致对速度（V1）和主动脉瓣面积（AVA）的高估。因此，建议从椭圆形远端LVOT（远离瓣环）的层流区域得出V1。除了与连续性方程（CE）的假设不一致外，流量和面积测量位置的空间差异也会导致AVA计算不准确。我们通过连续性方程（CE）评估了PLVOT中FA对主动脉瓣狭窄（AS）患者AVA准确性的影响。方法对AS患者进行一次基于CE的AVA计算，在远端LVOT（VTILVOT）和PLVOT中进行PWD导出的速度-时间积分（VTI），以获得每个患者的FA速度分布（FA-VTILVOT）。配对样本t检验（P < 0.05）来比较FA-VTILVOT和VTILVOT对AVA计算的影响。结果本研究共有46例患者。与峰值VTILVOT相比，峰值FA-VTILVOT增加了30.3%，并且通过FA-VTILVOT获得的AVA比通过VTILVOT获得的高29.1%。结论PLVOT中FA对AVA的准确性有显著影响。LVOT面积应通过远端LVOT的3D成像进行测量。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Echo Research and Practice CARDIAC & CARDIOVASCULAR SYSTEMS-

CiteScore

6.70

自引率

12.70%

发文量

审稿时长

8 weeks

期刊介绍： Echo Research and Practice aims to be the premier international journal for physicians, sonographers, nurses and other allied health professionals practising echocardiography and other cardiac imaging modalities. This open-access journal publishes quality clinical and basic research, reviews, videos, education materials and selected high-interest case reports and videos across all echocardiography modalities and disciplines, including paediatrics, anaesthetics, general practice, acute medicine and intensive care. Multi-modality studies primarily featuring the use of cardiac ultrasound in clinical practice, in association with Cardiac Computed Tomography, Cardiovascular Magnetic Resonance or Nuclear Cardiology are of interest. Topics include, but are not limited to: 2D echocardiography 3D echocardiography Comparative imaging techniques – CCT, CMR and Nuclear Cardiology Congenital heart disease, including foetal echocardiography Contrast echocardiography Critical care echocardiography Deformation imaging Doppler echocardiography Interventional echocardiography Intracardiac echocardiography Intraoperative echocardiography Prosthetic valves Stress echocardiography Technical innovations Transoesophageal echocardiography Valve disease.