van Dijk A P, Hopman J C, Klaessens J H, van der Werf T, Daniëls O
Children's Heart Centre, University Hospital Nijmegen, The Netherlands.
Am J Cardiol. 1996 Dec 15;78(12):1394-9. doi: 10.1016/s0002-9149(96)00643-1.
Noninvasive determination of pulmonary hemodynamics is important for the management of congenital heart disease complicated by pulmonary hypertension. Flow deceleration is less influenced by right ventricular function and would allow more accurate estimation of pulmonary hemodynamics than acceleration. Respiratory influences on pulmonary blood flow are exaggerated by mechanical ventilation. Doppler-derived pulmonary artery (PA) blood flow velocity characteristics were therefore compared with pulmonary hemodynamic parameters in 42 mechanically ventilated children, aged 0.2 to 14.8 years (mean +/- SD 6.7 +/- 4.9). Mean PA pressure ranged from 11 to 47 mm Hg (21 +/- 9 mm Hg). Pulmonary hypertension was present in 14 patients. Significant differences were found between patients with and without pulmonary hypertension in maximal velocity (1.03 +/- 0.22 vs 0.88 +/- 0.18 m/s), acceleration time (119 +/- 39 vs 136 +/- 29 ms), maximal acceleration (17.6 +/- 6.4 vs 13.1 +/- 4.0 m/s2), mean acceleration (9.3 +/- 2.6 vs 6.7 +/- 2.0 m/s2), and mean deceleration (4.5 +/- 1.0 vs 3.8 +/- 0.8 m/s2). In contrast to our hypothesis of the deceleration phase-derived parameters, only maximal deceleration correlated with PA pressure. Acceleration parameters showed closer relations with PA pressures, but correlations were generally low and did not permit accurate prediction of PA pressure (SEE 5 to 11 mm Hg), PA resistance (SEE 1.14 U. m2) or PA driving force (SEE 7 mm Hg). An analysis that took respiratory phase into account did not improve correlations. Measurement of mean acceleration, maximal deceleration, and rate-corrected preejection period permitted for accurate discrimination between the presence or absence of pulmonary hypertension, with positive and negative predictive values being 92% and 90%. In mechanically ventilated children with congenital heart disease, accurate noninvasive PA pressure assessment is not possible. Accurate predictions for the presence of pulmonary hypertension can be made by measurement of both acceleration and deceleration parameters.
无创测定肺血流动力学对于先天性心脏病合并肺动脉高压的治疗具有重要意义。血流减速受右心室功能的影响较小，与血流加速相比，能更准确地评估肺血流动力学。机械通气会放大呼吸对肺血流的影响。因此，我们比较了42例年龄在0.2至14.8岁（平均±标准差6.7±4.9岁）的机械通气儿童的多普勒衍生肺动脉（PA）血流速度特征与肺血流动力学参数。平均肺动脉压范围为11至47 mmHg（21±9 mmHg）。14例患者存在肺动脉高压。有肺动脉高压和无肺动脉高压患者在最大速度（1.03±0.22 vs 0.88±0.18 m/s）、加速时间（119±39 vs 136±29 ms）、最大加速度（17.6±6.4 vs 13.1±4.0 m/s²）、平均加速度（9.3±2.6 vs 6.7±2.0 m/s²）和平均减速（4.5±1.0 vs 3.8±0.8 m/s²）方面存在显著差异。与我们关于减速期衍生参数的假设相反，只有最大减速与肺动脉压相关。加速参数与肺动脉压的关系更密切，但相关性通常较低，无法准确预测肺动脉压（估计标准误差5至11 mmHg）、肺血管阻力（估计标准误差1.14 U·m²）或肺动脉驱动力（估计标准误差7 mmHg）。考虑呼吸相位的分析并未改善相关性。测量平均加速度、最大减速和心率校正的射血前期可准确区分有无肺动脉高压，阳性和阴性预测值分别为92%和90%。在患有先天性心脏病的机械通气儿童中，无法进行准确的无创肺动脉压评估。通过测量加速和减速参数可以对肺动脉高压的存在做出准确预测。
