Introduction/objectives

Echocardiographic diagnosis of pulmonary hypertension (PH) in horses is usually based on Doppler interrogation of tricuspid (TR) or pulmonic regurgitation (PR). This study aimed at investigating two-dimensional echocardiographic (2DE) variables, including pulmonary artery diameter (PAD) and pulmonary artery distensibility index (PADI), to diagnose PH.

Animals, materials and methods

41 healthy horses; 82 horses with TR or PR and normal intracardiac pressure gradients; and 35 horses with TR or PR velocities indicating PH. The 2DE variables were compared between groups, cut-offs for the diagnosis of PH were determined, and conditional inference trees served to identify the variable best predicting PH in the absence of TR or PR.

Results

Horses with PH had larger end-diastolic cross-sectional (short-axis) PAD (PAD_ed-sx) (5.8 ± 1.0 cm; mean ± SD) and smaller PADI_[/PADps] (15.4 ± 7.7%) than healthy horses (5.0 ± 0.6 cm, P<0.0001; 20.5 ± 4.4%, P<0.001) and horses with TR or PR but no PH (5.3 ± 0.6 cm, P=0.003; 18.8 ± 4.2%, P=0.005). PAD_ed-sx predicted PH with sensitivity (Se) = 36% and specificity (Sp) = 94% (cut-off 6.0 cm, AUC = 0.668, P=0.002), while PADI_[/PADps] predicted PH with Se = 43% and Sp = 92% (cut-off 13.7%, AUC = 0.662, P=0.004). In the absence of TR, PAD_ed-sx and the end-diastolic long-axis aortic diameter-to-PAD_ed-sx ratio (AoD_ed-lx/PAD_ed-sx) were most suitable to diagnose PH.

Conclusion

PAD_ed-sx and PADI were moderately specific but not very sensitive to diagnosing PH. Nonetheless, they may be used as complementary indices suggesting PH in the absence of TR or PR.

中文翻译：

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二维超声心动图测量肺动脉直径和肺动脉扩张指数对马肺动脉高压的诊断价值

简介/目标

马肺动脉高压 (PH) 的超声心动图诊断通常基于三尖瓣 (TR) 或肺动脉瓣反流 (PR) 的多普勒检查。本研究旨在研究二维超声心动图 (2DE) 变量，包括肺动脉直径 (PAD) 和肺动脉扩张指数 (PADI)，以诊断 PH。

动物、材料和方法

41匹健康马匹；82 匹 TR 或 PR 且心内压力梯度正常的马；以及 35 匹具有 TR 或 PR 速度（指示 PH）的马。比较各组之间的 2DE 变量，确定 PH 诊断的临界值，并使用条件推理树来识别在没有 TR 或 PR 的情况下最能预测 PH 的变量。

结果

与健康马相比，患有 PH 的马具有较大的舒张末期横截面（短轴）PAD (PAD _ed-sx ) (5.8 ± 1.0 cm；平均值 ± SD) 和较小的 PADI _[/PADps] (15.4 ± 7.7%)（ 5.0 ± 0.6 cm，P<0.0001；20.5 ± 4.4%，P<0.001）以及具有 TR 或 PR 但无 PH 的马（5.3 ± 0.6 cm，P=0.003；18.8 ± 4.2%，P=0.005）。PAD _ed-sx预测 PH 的灵敏度 (Se) = 36%，特异性 (Sp) = 94%（截止值 6.0 cm，AUC = 0.668，P=0.002），而 PADI _[/PADps]预测 PH 的 Se = 43 % 且 Sp = 92%（截止值 13.7%，AUC = 0.662，P=0.004）。在没有 TR 的情况下，PAD _ed-sx和舒张末期主动脉长轴直径与 PAD _ed-sx之比 (AoD _ed-lx /PAD _ed-sx ) 最适合诊断 PH。

结论

PAD _ed-sx和 PADI 具有中等特异性，但对诊断 PH 不太敏感。尽管如此，它们可以用作在没有 TR 或 PR 的情况下提示 PH 的补充指标。