Division of Paediatric Cardiology, Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong, China.
J Am Soc Echocardiogr. 2017 Oct;30(10):984-991. doi: 10.1016/j.echo.2017.06.021. Epub 2017 Aug 10.
Vector flow mapping (VFM) enables direct visualization of flow pattern and estimation of flow volume. The aim of this study was to determine its accuracy in the quantification of pulmonary regurgitation (PR) in congenital heart patients after repair of right ventricular (RV) outflow obstruction.
This study comprised two parts: (1) validation of VFM in the quantification of PR in patients with repaired tetralogy of Fallot by cardiac magnetic resonance and (2) clinical application of VFM to determine PR in patients after biventricular repair of pulmonary atresia and stenosis with intact ventricular septum. PR was quantified by calculation of VFM-derived pulmonary regurgitant ratio (PR), defined as ratio of backward to forward flow volume.
Coefficients of variations for intra- and interobserver variability in the measurements of PR were 7.0% and 10.4%, respectively. Fourteen patients with repaired tetralogy of Fallot aged 31.3 ± 7.3 years were studied. Their PR correlated strongly with cardiac magnetic resonance-derived PR fraction (r = 0.95, P < .001) and RV end-diastolic volume (r = 0.84, P < .001). In the second part, 14 patients with pulmonary atresia with intact ventricular septum aged 25.6 ± 6.0 years, 14 patients with pulmonary stenosis aged 24.2 ± 7.0 years, and 14 healthy control subjects were studied. PR was found to increase across groups of subjects with absent (4.6 ± 3.3%), mild (11.1 ± 7.1%), moderate (29.6 ± 7.8%), and severe (50.1 ± 8.2%) PR as defined semiquantitatively by color flow mapping. Furthermore, PR correlated strongly with the ratio of PR color jet to width of RV outflow (r = 0.92, P < .001).
VFM is a reproducible technique for accurate quantification of PR in congenital heart patients after repair of RV outflow obstruction.
向量流图（VFM）可直接可视化血流模式并估计血流量。本研究旨在确定其在评估右心室（RV）流出道梗阻修复后先天性心脏病患者肺反流（PR）中的准确性。
本研究包括两部分：（1）通过心脏磁共振验证 VFM 在法洛四联症修复患者 PR 定量中的准确性；（2）通过 VFM 临床应用确定室间隔完整的肺动脉瓣闭锁和狭窄患者双心室修复后的 PR。PR 通过计算 VFM 衍生的肺反流比（PR）来量化，定义为反流与前向血流之比。
PR 测量的观察者内和观察者间变异系数分别为 7.0%和 10.4%。研究了 14 名年龄为 31.3±7.3 岁的法洛四联症修复患者。他们的 PR 与心脏磁共振衍生的 PR 分数（r=0.95，P<0.001）和 RV 舒张末期容积（r=0.84，P<0.001）密切相关。在第二部分中，研究了 14 名年龄为 25.6±6.0 岁的室间隔完整的肺动脉瓣闭锁患者、14 名年龄为 24.2±7.0 岁的肺动脉瓣狭窄患者和 14 名健康对照者。根据彩色血流图半定量定义，发现 PR 在无 PR（4.6±3.3%）、轻度 PR（11.1±7.1%）、中度 PR（29.6±7.8%）和重度 PR（50.1±8.2%）的患者中逐渐增加。此外，PR 与 RV 流出道 PR 彩色射流与宽度的比值密切相关（r=0.92，P<0.001）。
VFM 是一种可重复的技术，可准确评估 RV 流出道梗阻修复后先天性心脏病患者的 PR。
