Department of Cardiology, Leiden University Medical Centre, Leiden, the Netherlands.
Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Université Laval, Québec City, Québec, Canada.
JACC Cardiovasc Imaging. 2019 Feb;12(2):267-282. doi: 10.1016/j.jcmg.2018.11.027.
Up to 40% of patients with aortic stenosis (AS) present with a "discordant grading" usually referred to as "low-gradient AS." This article presents a step-by-step integrative approach overview of the utility, limitations, and complementary role of the different imaging modalities for the assessment of AS severity with a special emphasis on the reconciliation of discordant grading. The first step is to confirm the validity of echocardiographic measures of AS severity. For example, hybrid imaging can combine left ventricular outflow tract area measured by 3-dimensional echocardiography or contrast enhanced multidetector row computed tomography with flow velocities measured by Doppler. The next step is to differentiate severe from non-severe AS with the use of low-dose dobutamine stress echocardiography, especially in patients with low left ventricular ejection fraction, low-flow, low-gradient AS. Aortic valve calcium scoring measured by noncontrast multidetector row computed tomography is preferred in patients with low-gradient AS and preserved left ventricular ejection fraction as well as in those with inconclusive results with dobutamine stress echocardiography.
高达 40%的主动脉瓣狭窄（AS）患者存在“不一致分级”，通常被称为“低梯度 AS”。本文提出了一种逐步综合的方法，概述了不同影像学方法在评估 AS 严重程度方面的应用、局限性和互补作用，特别强调了不一致分级的协调。第一步是确认超声心动图评估 AS 严重程度的有效性。例如，混合成像可以将 3 维超声心动图或对比增强多排 CT 测量的左心室流出道面积与多普勒测量的血流速度相结合。下一步是使用低剂量多巴酚丁胺负荷超声心动图来区分严重和非严重 AS，特别是在左心室射血分数低、低流量、低梯度 AS 的患者中。对于低梯度 AS 且左心室射血分数保留的患者，以及多巴酚丁胺负荷超声心动图结果不确定的患者，推荐使用非增强多排 CT 测量主动脉瓣钙评分。
