BACKGROUND Pulmonary arterial hypertension (PAH) can cause maladaptive right ventricular (RV) functional changes associated with adverse prognosis that are challenging to accurately quantify noninvasively. The aim of this study was to explore principal strain (PS) with contraction angle analysis using three-dimensional echocardiography to characterize RV deformation changes in patients with PAH. METHODS Three-dimensional echocardiography was performed in 37 patients with PAH and 20 healthy control subjects with two-component (primary and secondary) PS and principal contraction angle analysis. Patients were stratified according to World Health Organization (WHO) functional class. RESULTS Primary PS differed significantly between patients with PAH and healthy control subjects (-20.2 ± 3.3% vs -26.8 ± 3.3%, P = .01), while secondary PS was not significantly different (3.6 ± 5.1% vs -2.5 ± 4.7%, P = .12). Principal contraction angle was significantly lower in patients with PAH (63 ± 22° vs 71 ± 7°, P = .01), with the greatest reduction for the RV free wall. Primary PS and principal contraction angle differed significantly between WHO class I and II and class III and IV patients (-23.9 ± 4.7% vs -18.1 ± 4.8% [P = .03] and 69 ± 9° vs 58 ± 14° [P = .03], respectively), while secondary PS was not significantly different between groups (P = .13). Compared with healthy control subjects, septal principal contraction angle was not different in patients with WHO class I and II PAH (P = .62), but it was significantly reduced in those with WHO class III and IV PAH (P < .01). The area under the curve for primary PS to differentiate patients with PAH by WHO functional class was 0.81 (95% CI, 0.77-0.89; P = .01). Primary PS intraclass correlation coefficients for intraobserver and interobserver variability were 0.91 (95% CI, 0.88-0.93) and 0.86 (95% CI, 0.81-0.88), respectively. CONCLUSIONS PS analysis using three-dimensional echocardiography provides comprehensive quantification of RV deformation and characterizes alterations occurring in PAH that are associated with WHO functional class.

中文翻译：

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使用三维主应变分析表征肺动脉高压中的右心室变形。

背景技术肺动脉高压（PAH）可能会导致与不良预后相关的适应不良的右心室（RV）功能改变，这对于准确地无创地量化具有挑战性。这项研究的目的是通过使用三维超声心动图的收缩角分析探索主应变（PS），以表征PAH患者的RV变形变化。方法对37例PAH患者和20例健康对照者进行三维超声心动图检查，并进行两成分（主要和次要）PS并进行主收缩角分析。根据世界卫生组织（WHO）的功能分类对患者进行分层。结果PAH患者与健康对照组之间的原发性PS差异显着（-20.2±3.3％vs -26.8±3.3％，P = .01），而次级PS的差异无统计学意义（3.6±5.1％vs -2.5±4.7％，P = 0.12）。PAH患者的主收缩角显着降低（63±22°与71±7°，P = 0.01），而无RV壁的减少最大。WHO I级和II级以及III级和IV级患者的原发性PS和主收缩角显着不同（-23.9±4.7％vs -18.1±4.8％[P = .03]和69±9°vs 58±14°[P =分别为.03]），而各组之间的次级PS并无显着差异（P = .13）。与健康对照组相比，WHO I级和II级PAH患者的间隔主收缩角度无差异（P = .62），而WHO III级和IV级PAH患者的间隔主收缩角度则显着降低（P <.01）。根据WHO功能分类，原发性PS区分PAH患者的曲线下面积为0.81（95％CI，0.77-0.89； P = 0.01）。观察者内和观察者间变异性的主要PS类内相关系数分别为0.91（95％CI，0.88-0.93）和0.86（95％CI，0.81-0.88）。结论使用三维超声心动图的PS分析可对RV变形进行全面量化，并表征PAH中发生的与WHO功能分类相关的改变。