Background: Pulmonary arterial wave reflection (PAWR) occurs when the forward blood flow out the right ventricle is reflected by the pulmonary arterial tree, generating a backward wave. PAWR assessed by cardiac catheterization has been used to obtain information regarding pulmonary artery hemodynamics in pulmonary hypertension (PH) in people. However, diagnostic cardiac catheterization is not commonly used in small animal medicine because it is invasive and requires anesthesia. Hypothesis/Objective: To investigate whether PAWR can be assessed non-invasively in dogs with suspected PH using Doppler echocardiography, based on wave intensity analysis (WIA). In addition, the method was validated in a dog model of acute pulmonary embolism. Animals: Fifty-one client-owned dogs with tricuspid valve regurgitation were included in the clinical study (thirty-five with suspected PH and sixteen without echocardiographic evidence of PH) and eight healthy beagle dogs were included in the validation study. Methods: PAWR was assessed by separating pulmonary artery pulse pressure waveforms, which were estimated from the flow profile of tricuspid regurgitation, into forward (Pf) and backward pressures (Pb) using WIA. Reflection coefficient (RC) was defined as the ratio of peak Pb to peak Pf. We investigated the relationships between RC, cause, and survival time in dogs with suspected PH. In addition, we performed a validation study to compare PAWR obtained by cardiac catheterization and PAWR by Doppler echocardiography in dogs with experimentally-induced PH. Results: RC was significantly higher in dogs with suspected PH than in dogs without echocardiographic evidence of PH (0.18 ± 0.13 vs. 0.59 ± 0.21, P 0.48 had a significantly shorter survival time than dogs with RC < 0.48 (x2 = 9.8, log-rank test, p = 0.0018, median survival time 353 days vs. 110 days). In the validation study, RC obtained by Doppler echocardiography was significantly correlated with RC obtained by cardiac catheterization (r = 0.81, P < .001). Conclusions: PAWR analysis performed by echocardiography seems feasible in dogs and could provide useful information for classification and prognosis in canine PH.

中文翻译：

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疑似肺动脉高压犬肺动脉波反射的无创评估。

背景：当从右心室流出的正向血流被肺动脉树反射时，会发生肺动脉波反射 (PAWR)，产生反向波。通过心导管术评估的 PAWR 已被用于获取有关人类肺动脉高压 (PH) 肺动脉血流动力学的信息。然而，诊断性心导管插入术在小动物医学中并不常用，因为它是侵入性的并且需要麻醉。假设/目的：基于波强度分析 (WIA)，研究是否可以使用多普勒超声心动图对疑似 PH 的狗进行无创评估 PAWR。此外，该方法在急性肺栓塞的狗模型中得到了验证。动物：51 只客户拥有的三尖瓣反流犬被纳入临床研究（35 只疑似 PH，16 只无超声心动图 PH 证据），8 只健康比格犬纳入验证研究。方法：通过使用 WIA 将肺动脉脉压波形（根据三尖瓣返流的流量分布估计）分离为正向压力 (Pf) 和反向压力 (Pb) 来评估 PAWR。反射系数 (RC) 定义为峰值 Pb 与峰值 Pf 的比率。我们调查了疑似 PH 犬的 RC、原因和存活时间之间的关系。此外，我们进行了一项验证研究，以比较实验诱导的 PH 狗通过心导管术获得的 PAWR 和多普勒超声心动图获得的 PAWR。结果：中位生存时间 353 天与 110 天）。在验证研究中，多普勒超声心动图获得的 RC 与心导管术获得的 RC 显着相关（r = 0.81，P < .001）。结论：通过超声心动图进行的 PAWR 分析在犬中似乎是可行的，并且可以为犬 PH 的分类和预后提供有用的信息。中位生存时间 353 天与 110 天）。在验证研究中，多普勒超声心动图获得的 RC 与心导管术获得的 RC 显着相关（r = 0.81，P < .001）。结论：通过超声心动图进行的 PAWR 分析在犬中似乎是可行的，并且可以为犬 PH 的分类和预后提供有用的信息。