超声心动图无创性评估肺血管阻力

Non-invasive Assessment of Pulmonary Vascular Resistance by Echocardiography

目的比较超声心动图与右心导管检测肺血管阻力(PVR)的结果,探讨多普勒超声心动图无创、定量评估PVR的可行性。资料与方法 28例拟诊为肺动脉高压(PH)的患者,采用多普勒超声测量右心室流出道时间流速积分(TVIRVOT)和三尖瓣收缩期反流血流频谱最大速度(TRV),并采用多普勒超声测算公式1(PVRecho1=TRV/TVIRVOT×10+0.16)及公式2(PVRecho2=TRV2/TVIRVOT×5.19-0.4)分别计算PVR。同时采用右心导管检测肺动脉压力和心排量,并采用Fick法计算PVR。依据右心导管测量结果将患者分为肺阻力略增高组(PVR≤6 Wood)和肺阻力显著增高组(PVR>6 Wood),评价公式1及公式2所测得PVR与右心导管测值的一致性。结果采用多普勒超声测算公式1和公式2所测得PVR与右心导管测值在不分组和分组时均呈显著正相关(r=0.881、0.895、0.925,P<0.01),但公式1所测得PVR仅在肺阻力略增高组与右心导管测值一致性好,公式2所测得PVR与右心导管测值在各组一致性均无显著差异,公式2在肺阻力略增高组患者所测得PVR与右心导管测值比较的偏倚性较公式1大。以TRV/TVIRVOT>0.19作为阈值,区分PVR>6 Wood的敏感度(100%)和特异度(80%)较好。结论多普勒超声心动图可以快速、无创地定量评估PVR,但在临床工作中需注意不同程度PVR增高的患者应使用不同的测算公式。

Purpose To discuss the feasibility of assessing pulmonary vascular resistance （PVR） by Doppler echocardiography as a non-invasive measurement through a comparative analysis of Doppler echocardiography and right cardiac catheterization. Materials and Methods Twenty-eight patients with suspected pulmonary hypertension （PH） were enrolled in the study. The time-velocity integral of the right ventricular outflow tract （TVIRVOT） and tricuspid regurgitation velocity （TRV） were measured by Doppler ultrasound, and PVR was calculated according to formula 1 （PVRechol=TRV/ TVIRCOT× 10＋0.16） and formula 2 （PVRecho2=TRV2/TVIRVOT×5.19- 0.4） respectively. Meanwhile, pulmonary arterial pressure and cardiac output were detected by right cardiac catheterization, and PVR was obtained by using the Fick method. The patients were further divided into the slightly increased PVR group （PVR ≤ 6 Wood） and the obviously increased PVR group （PVR〉6 Wood） according to the measurement of right cardiac catheterization. The correlation of the results obtained by the two means was assessed. Results The PVR calculated by Doppler ultrasound using formula 1 and 2 and that by right cardiac catheterization was positively correlated no matter grouping was considered or not （r=0.881,0.895 and 0.925, P〈0.01）. However, the PVR calculated by using formula 1 only showed better consistency with that by right cardiac catheterization in the slightly increased PVR group; the PVR by using formula 2 had no significant consistency with either group. Further Bland ＆ Altman analysis revealed that, in the slightly increased PVR group, the PVR calculated by using formula 2 had a bigger bias than that by using formula 1. Taking TRV/TVIRVOT〉0.19 as the cutoff value to distinguish PVR〉6 Wood had good sensitivity and specificity of 100% and 80%, respectively. Conclusion Doppler echocardiography can be used as a rapid, noninvasive and quantitative way to measure pulmonary vascular resistance, but increased PVR with different degrees should be analyzed by using different calculation formulae.