Estimation of central aortic pressure waveform by mathematical transformation of radial tonometry pressure. Validation of generalized transfer function.
Estimation of central aortic pressure waveform by mathematical transformation of radial tonometry pressure. Validation of generalized transfer function.
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DOI：
10.1161/01.cir.95.7.1827
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发表时间：
1997-04
期刊：
影响因子：
37.8
通讯作者：
Chen-Huan Chen-Chen-Huan-Chen-10355153;E. Nevo;B. Fetics;P. Pak;F. Yin;W. Maughan;D. Kass
中科院分区：
文献类型：
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作者：
Chen-Huan Chen-Chen-Huan-Chen-10355153;E. Nevo;B. Fetics;P. Pak;F. Yin;W. Maughan;D. Kass
中心主动脉压和波形传达了关于心血管状态的重要信息，但直接测量是有创的。外周压力可以非侵入性地测量，尽管它们通常与中心压力有很大差异，但它们可以通过数学变换来近似后者。我们测试了这种方法，检查受试者间和受试者内的变化和使用一个单一的平均转换，这将提高其适用性的有效性。方法和结果在稳态和血流动力学瞬变（Valsalva动作，腹部压迫，硝酸甘油，或腔静脉阻塞）时，测量20例患者的有创中心主动脉压微压计和径向压力自动张力计。对于每名患者，通过参数模型计算主动脉压和桡动脉压之间的传递函数（TF），并对结果进行平均以产生个体TF。广义TF是各个函数的平均值。TF因患者而异，峰值振幅和峰值振幅处频率的变异系数分别为24.9%和16.9%。在28.5%的患者中观察到患者内TF随负荷改变而变化（峰值振幅变化> 20%）。尽管如此，广义TF估计中心动脉压的误差≤ 0.2 +/- 3.8 mm Hg，动脉顺应性的准确度为6 +/- 7%，增强指数在-7%点内（30 +/- 45%准确度）。单个TF在重建中心压方面仅略优于广义TF上级。结论：中心主动脉压可以准确地估计径向张力与广义TF的使用。重建的波形可以提供动脉顺应性估计，但可能会低估增强指数，因为后者需要更大的保真度再现波轮廓。
BACKGROUND Central aortic pressures and waveform convey important information about cardiovascular status, but direct measurements are invasive. Peripheral pressures can be measured noninvasively, and although they often differ substantially from central pressures, they may be mathematically transformed to approximate the latter. We tested this approach, examining intersubject and intrasubject variability and the validity of using a single averaged transformation, which would enhance its applicability. METHODS AND RESULTS Invasive central aortic pressure by micromanometer and radial pressure by automated tonometry were measured in 20 patients at steady state and during hemodynamic transients (Valsalva maneuver, abdominal compression, nitroglycerin, or vena caval obstruction). For each patient, transfer functions (TFs) between aortic and radial pressures were calculated by parametric model and results averaged to yield individual TFs. A generalized TF was the average of individual functions. TFs varied among patients, with coefficients of variation for peak amplitude and frequency at peak amplitude of 24.9% and 16.9%, respectively. Intrapatient TF variance with altered loading (> 20% variation in peak amplitude) was observed in 28.5% of patients. Despite this, the generalized TF estimated central arterial pressures to < or = 0.2 +/- 3.8 mm Hg error, arterial compliance to 6 +/- 7% accuracy, and augmentation index to within -7% points (30 +/- 45% accuracy). Individual TFs were only marginally superior to the generalized TF for reconstructing central pressures. CONCLUSIONS Central aortic pressures can be accurately estimated from radial tonometry with the use of a generalized TF. The reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.