Department of Cardiology, Children's Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA.
J Am Soc Echocardiogr. 2011 Jun;24(6):637-43. doi: 10.1016/j.echo.2011.01.020. Epub 2011 Mar 9.
The influence of regional right ventricular (RV) dysfunction on the accuracy of Doppler tissue imaging (DTI) assessment of global RV function is unknown. The objective of this study was to determine the effect of regional dysfunction of the RV outflow tract (RVOT) on the correlations between RV DTI indices and cardiac magnetic resonance (CMR) measurements of global RV function in patients with repaired tetralogy of Fallot.
Consecutive patients with repaired tetralogy of Fallot who underwent echocardiography with DTI of the right ventricle and CMR within 4 weeks of each other were retrospectively analyzed. RV DTI measurements were obtained from the lateral wall at the level of the tricuspid valve annulus. CMR measurements included end-diastolic and end-systolic volumes, stroke volume, and ejection fraction (EF) of the entire right ventricle and measured separately for the RV sinus and RVOT segments.
The median age of the 51 patients included was 19 years (range, 9.7-71.6 years), and the median interval between echocardiography and CMR was 0 days. The mean RV free wall peak S', isovolumic acceleration, and global, sinus, and RVOT EFs were 8.4 ± 2.0 cm/s, 102 ± 37 cm/s(2), and 46.1 ± 9.8%, 47.9 ± 9.9%, and 33 ± 13.1%, respectively. The correlation between peak S' and global RV EF was weak (r = 0.23) in patients with RVOT dysfunction (RVOT EF <30%) but higher (r = 0.66) in those with RVOT EFs ≥30%. Peak S' ≥8.4 cm/s (area under the receiver operating characteristic curve, 0.77) and isovolumic acceleration ≥95 cm/s(2) (area under the receiver operating characteristic curve, 0.68) best discriminated between patients with global RV EFs >45% and <45%.
In this group of patients with repaired TOF, RV DTI indices showed reasonable correlation with CMR-derived global RV EF, but this correlation was substantially weaker in those with moderate and severe dysfunction of the RVOT. Peak S' <8.4 cm/s and isovolumic acceleration <95cm/s(2) by DTI should prompt an evaluation of RV function by CMR.
右心室（RV）局部功能障碍对多普勒组织成像（DTI）评估整体 RV 功能的准确性的影响尚不清楚。本研究的目的是确定 RV 流出道（RVOT）局部功能障碍对法洛四联症修复患者的 RV DTI 指数与心脏磁共振（CMR）测量的整体 RV 功能之间相关性的影响。
对连续接受 RV DTI 检查的法洛四联症修复患者进行回顾性分析，这些患者在 4 周内接受了超声心动图检查，并进行了 CMR 检查。RV DTI 测量值取自三尖瓣环水平的外侧壁。CMR 测量值包括整个右心室的舒张末期和收缩末期容积、stroke volume 和射血分数（EF），并分别测量 RV 窦和 RVOT 节段。
51 例患者的中位年龄为 19 岁（范围：9.7-71.6 岁），超声心动图和 CMR 之间的中位间隔为 0 天。RV 游离壁峰值 S'、等容加速度和整体、窦和 RVOT EF 的平均值分别为 8.4 ± 2.0cm/s、102 ± 37cm/s(2)、46.1 ± 9.8%、47.9 ± 9.9%和 33 ± 13.1%。在 RVOT 功能障碍（RVOT EF <30%）患者中，峰值 S'与整体 RV EF 的相关性较弱（r=0.23），而在 RVOT EF ≥30%的患者中，相关性较强（r=0.66）。峰值 S'≥8.4cm/s（曲线下面积，0.77）和等容加速度≥95cm/s(2)（曲线下面积，0.68）最佳区分了整体 RV EF >45%和 <45%的患者。
在这组法洛四联症修复患者中，RV DTI 指数与 CMR 衍生的整体 RV EF 具有合理的相关性，但在 RVOT 中度和重度功能障碍患者中，相关性明显减弱。DTI 的峰值 S'＜8.4cm/s 和等容加速度＜95cm/s(2)应提示通过 CMR 评估 RV 功能。
