Ajami Gholam Hossein, Cheriki Sirous, Amoozgar Hamid, Borzouee Mohammad, Soltani Manoucher
Department of Pediatrics, Division of Pediatric Cardiology, Namazi Hospital, Shiraz University of Medical Sciences, 71937-11351, Shiraz, Iran.
Pediatr Cardiol. 2011 Dec;32(8):1168-74. doi: 10.1007/s00246-011-0035-4. Epub 2011 Jul 22.
Pulmonary vascular resistance (PVR) is a critical and essential parameter during the assessment and selection of modality of treatment in patients with congenital heart disease (CHD) accompanied by pulmonary arterial hypertension (PAH). Cardiac catheterization is the "gold standard" but is an invasive method for PVR measurement. A noninvasive and reliable method for estimation of PVR in children has been a major challenge and most desirable during past decades, especially for those who need repeated measurements. In a prospective study and among consecutive patients who were referred for cardiac catheterizations, PVR was calculated as the ratio of the transpulmonary pressure gradient (∆P) to the amount of the pulmonary flow (QP) accordingly for 20 patients with CHD and high PAH. Subsequently and noninvasively, PVR was assessed for these patients by a Doppler echocardiography-derived index defined as the ratio of the tricuspid regurgitation velocity (TRV(m/s)) to the velocity time integral (VTI(cm)) of the right-ventricular outflow tract (RVOT). There was a good correlation between PVR measured at catheterization (PVR(cath)) and TRV/VTI(m) ratio; the mean of three measurements of VTI (VTI(m)) with R (2) = 0.53 (p = 0.008). In addition, a TRV/VTI(m) value of 0.2 provided a sensitivity of 71.4% and a specificity of 100% for PVR >6 Woods units (WU) as well as sensitivity of 90% and specificity of 90% for a PVR equal to 8 WU. PVR value between 6 and 8 WU by catheterization has been considered as a cut-off point for intervention in children with left-to-right shunts and PAH. In conclusion, Doppler-derived TRV/VTI(m) ratio is a reliable index that may be helpful as a supplementary diagnostic tool for the selection of modality of treatment and follow-up of patients with PAH and increased PVR.
肺血管阻力（PVR）是评估和选择先天性心脏病（CHD）合并肺动脉高压（PAH）患者治疗方式时的一个关键且重要的参数。心导管检查是PVR测量的“金标准”，但却是一种侵入性方法。在过去几十年里，寻找一种无创且可靠的儿童PVR估算方法一直是一项重大挑战，也是最迫切需要的，尤其是对于那些需要反复测量的患者。在一项前瞻性研究中，对连续接受心导管检查的患者进行研究，按照相应公式，将20例CHD合并重度PAH患者的PVR计算为经肺压力梯度（∆P）与肺血流量（QP）的比值。随后，通过一种经多普勒超声心动图得出的指标对这些患者进行无创PVR评估，该指标定义为三尖瓣反流速度（TRV（m/s））与右心室流出道（RVOT）速度时间积分（VTI（cm））的比值。心导管检查测得的PVR（PVR（cath））与TRV/VTI（m）比值之间存在良好的相关性；VTI三次测量值的平均值（VTI（m）），R（2） = 0.53（p = 0.008）。此外，当PVR >6伍兹单位（WU）时，TRV/VTI（m）值为0.2时的敏感性为71.4%，特异性为100%；当PVR等于8 WU时，敏感性为90%，特异性为90%。心导管检查得出的PVR值在6至8 WU之间被视为左向右分流且合并PAH儿童的干预临界点。总之，经多普勒得出的TRV/VTI（m）比值是一个可靠的指标，可能有助于作为一种辅助诊断工具，用于PAH和PVR升高患者治疗方式的选择及随访。
