Bhyravavajhala Srinivas, Velam Vanajakshamma, Polapragada Nishanth V, Pallempati Pranav, Iragavarapu Tammi Raju, Patnaik Amar Narayan, Damera Seshagiri Rao
Department of Cardiology, Nizam's Institute of Medical Sciences, Hyderabad, India.
Depatment of Cardiology, Sri Venkateswara Institute of Medical Sciences, Tirupathi, India.
Echocardiography. 2015 Jun;32(6):1009-14. doi: 10.1111/echo.12779. Epub 2014 Sep 24.
Pulmonary vascular resistance (PVR) is a crucial parameter in the management of patients with left-to-right shunt lesions. Cardiac catheterization (Cath) is the gold standard test to assess PVR (PVRcath ), but it is invasive and hence, risky in children with pulmonary arterial hypertension (PAH). A noninvasive tool to assess PVR is desirable. Ratio of tricuspid regurgitation velocity (TRV) and time-velocity integral of right ventricular outflow tract (TVIRVOT ) by Doppler was previously shown to be a reliable noninvasive method for estimation of PVR in acquired PAH.
Peak TR velocity and TVIRVOT were recorded from 63 prospective patients with various congenital shunt lesions. Subsequently, the patients were subjected to cath in less than 2 hours. The patients were subdivided into four subsets based on age and pulmonary arterial mean pressure (PAMP). A regression equation was developed for calculation of PVR from TRV/TVIRVOT (PVREcho ) which was indexed for BSA (PVRIEcho ). Bland-Altman analysis was done for agreement between PVRIcath and PVRIEcho . Receiver operating characteristic (ROC) curves were plotted to test the identity of the two methods and also the applicability of PVRIEcho across a wide range of Wood units.
Receiver operating characteristic curve plotted between the two methods showed good identity. Bland-Altman analysis showed excellent agreement between the two methods with negligible bias. ROC curves showed that PVRIEcho was accurate in distinguishing different cutoff values of PVR in each of the 4 groups.
Noninvasive Doppler estimation of PVR is reliable in patients with shunt lesions over a wide range of PVR.
肺血管阻力（PVR）是左向右分流性病变患者治疗中的关键参数。心导管检查（Cath）是评估PVR（PVRcath）的金标准检查，但它具有侵入性，因此对于患有肺动脉高压（PAH）的儿童有风险。需要一种非侵入性工具来评估PVR。先前研究表明，通过多普勒测量的三尖瓣反流速度（TRV）与右心室流出道时间速度积分（TVIRVOT）之比是评估获得性PAH中PVR的可靠非侵入性方法。
记录了63例患有各种先天性分流病变的前瞻性患者的TR峰值速度和TVIRVOT。随后，患者在不到2小时内接受了心导管检查。根据年龄和肺动脉平均压（PAMP）将患者分为四个亚组。建立了一个回归方程，用于从TRV/TVIRVOT（PVREcho）计算PVR，并根据体表面积（BSA）进行指数化（PVRIEcho）。对PVRIcath和PVRIEcho之间的一致性进行了Bland-Altman分析。绘制了受试者操作特征（ROC）曲线，以检验两种方法的一致性，以及PVRIEcho在广泛的伍德单位范围内的适用性。
两种方法之间绘制的ROC曲线显示出良好的一致性。Bland-Altman分析显示两种方法之间具有极好的一致性，偏差可忽略不计。ROC曲线表明，PVRIEcho在区分4组中每组不同的PVR临界值时是准确的。
在广泛的PVR范围内，对分流性病变患者进行无创多普勒PVR估计是可靠的。
