School of Biomedical Engineering and Imaging Sciences, Kings College London, London, UK.
Cardiovascular Ultrasound, GE Vingmed, Oslo, Norway.
J Hypertens. 2021 Jul 1;39(7):1421-1428. doi: 10.1097/HJH.0000000000002813.
Basal septal hypertrophy (BSH) is an asymmetric, localized thickening of the upper interventricular septum and constitutes a marker of an early remodelling in patients with hypertension. This morphological trait has been extensively researched because of its prevalence in hypertension, yet its clinical and prognostic value for individual patients remains undetermined. One of the reasons is the lack of a reliable and reproducible metric to quantify the presence and the extent of BSH. This article proposes the use of the curvature of the left ventricular endocardium as a robust feature for BSH characterization, and as an objective criterion to quantify current subjective 'visual assessment' of the presence of sigmoidal septum. The proposed marker, called average septal curvature, is defined as the inverse of the radius adjacent to each point of the endocardial contour along the basal and mid inferoseptal segments of the left ventricle.
Robustness and reproducibility were assessed on a cohort of 220 patients, including 161 hypertensive patients (32 with BSH) and 59 healthy controls.
The results show that compared with the conventionally used wall thickness metrics, the new marker is more reproducible (relative standard deviation of errors of 7 vs. 13%, and 8 vs. 38% for intra-observer and inter-observer variability, respectively) and better correlates to the functional parameters related to BSH, with main difference (absolute rank correlation 0.417 vs. 0.341) in local deformation changes assessed by longitudinal strain.
Average septal curvature is a more precisely defined and reproducible metric than thickness ratios, it can be fully automated, and better infers the functional remodelling related to hypertension.
基底隔肥厚（BSH）是一种非对称性、局限性的室间隔上部增厚，是高血压患者早期重塑的标志。这种形态特征已经被广泛研究，因为它在高血压中很常见，但它对个体患者的临床和预后价值仍不确定。原因之一是缺乏可靠和可重复的指标来量化 BSH 的存在和程度。本文提出使用左心室心内膜的曲率作为 BSH 特征化的稳健特征，以及作为量化当前主观“视觉评估”存在矢状隔的客观标准。所提出的标记物称为平均隔曲率，定义为左心室基底和中隔段心内膜轮廓上每个点与相邻点之间的半径的倒数。
在 220 名患者的队列中评估了稳健性和可重复性，其中包括 161 名高血压患者（32 名有 BSH）和 59 名健康对照者。
结果表明，与传统使用的壁厚度指标相比，新标记物具有更高的可重复性（误差的相对标准偏差分别为 7%和 13%，以及 8%和 38%，用于观察者内和观察者间变异性），并且与与 BSH 相关的功能参数相关性更好，主要差异（绝对秩相关 0.417 与 0.341）在于纵向应变评估的局部变形变化。
平均隔曲率是一种比厚度比更精确定义和可重复的指标，它可以完全自动化，并且更好地推断与高血压相关的功能重塑。
