Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart and Lung Institute, Laval University, Québec City, Québec, Canada.
Université de Nantes, CHU Nantes, CNRS, UNSERM, l'Institut du Thorax, Nantes, France.
J Am Soc Echocardiogr. 2021 Jan;34(1):62-71. doi: 10.1016/j.echo.2020.08.022. Epub 2020 Oct 14.
Transthoracic echocardiography (TTE) is the reference method for evaluation of aortic stenosis (AS), and it is extensively used to quantitate left ventricular (LV) mass and volumes. Regional upper septal hypertrophy (USH) or septal bulge is a frequent finding in patients with AS and may lead to overestimation of LV mass when using linear measurements. The objective of this study was to compare estimates of LV mass obtained by two-dimensional transthoracic echocardiographic LV dimensions measured at different levels of the LV cavity with those obtained by cardiovascular magnetic resonance (CMR).
One hundred six patients (mean age, 63 ± 15 years; 68% men) with AS were included in this subanalysis of the PROGRESSA study. Two-dimensional transthoracic echocardiographic measurements of LV dimensions were obtained at the basal level (BL; as recommended in guidelines), immediately below the septal bulge (BSB), and at a midventricular level (ML). Regional USH was defined as a basal interventricular septal thickness ≥ 13 mm and >1.3 times the thickness of the septal wall at the ML. Agreement between transthoracic echocardiographic and CMR measures was evaluated using Bland-Altman analysis.
The distribution of AS severity was mild in 23%, moderate in 57%, and severe in 20% of patients. Regional USH was present in 28 patients (26%). In the whole cohort, two-dimensional TTE overestimated LV mass (bias: BL, +60 ± 31 g; BSB, +59 ± 32 g; ML, +54 ± 32 g; P = .02). The biplane Simpson method slightly but significantly underestimated LV end-diastolic volume (bias -10 ± 20 mL, P < .001) compared with CMR. Overestimation of LV mass was more marked in patients with USH when measuring at the BL and was significantly lower when measuring LV dimensions at the ML (P < .025 vs BL and BSB).
Two-dimensional TTE systematically overestimated LV mass and underestimated LV volumes compared with CMR. However, the bias between TTE and CMR was less important when measuring at the ML. Measurements at the BL as suggested in guidelines should be avoided, and measurements at the ML should be preferred in patients with AS, especially in those with USH.
经胸超声心动图（TTE）是评估主动脉瓣狭窄（AS）的参考方法，广泛用于定量左心室（LV）质量和容量。局灶性上间隔肥厚（USH）或间隔膨出是 AS 患者的常见表现，当使用线性测量时，可能导致 LV 质量的高估。本研究的目的是比较二维经胸超声心动图测量的 LV 腔不同水平的 LV 尺寸与心血管磁共振（CMR）获得的 LV 质量估计值。
这项 PROGRESSA 研究的亚分析纳入了 106 例 AS 患者（平均年龄 63 ± 15 岁；68%为男性）。在基底水平（BL；按指南推荐）、紧邻间隔膨出下方（BSB）和中隔水平（ML）获得二维经胸超声心动图 LV 尺寸的测量值。局灶性 USH 定义为基底室间隔厚度≥13mm 且比 ML 处间隔壁厚度大 1.3 倍。使用 Bland-Altman 分析评估经胸超声心动图和 CMR 测量值之间的一致性。
AS 严重程度的分布为轻度 23%、中度 57%和重度 20%。28 例患者存在局灶性 USH（26%）。在整个队列中，二维 TTE 高估了 LV 质量（偏差：BL，+60 ± 31g；BSB，+59 ± 32g；ML，+54 ± 32g；P =.02）。与 CMR 相比，双平面 Simpson 法略但显著低估了 LV 舒张末期容积（偏差-10 ± 20mL，P <.001）。当在 BL 处测量时，USH 患者的 LV 质量高估更明显，而当在 ML 处测量 LV 尺寸时，LV 质量显著降低（P <.025 与 BL 和 BSB）。
与 CMR 相比，二维 TTE 系统地高估了 LV 质量并低估了 LV 容量。然而，当在 ML 处测量时，TTE 和 CMR 之间的偏差并不重要。应避免按指南建议在 BL 处测量，应优先在 AS 患者，特别是在存在 USH 的患者中在 ML 处测量。
