Truong Quynh A, Singh Jagmeet P, Cannon Christopher P, Sarwar Ammar, Nasir Khurram, Auricchio Angelo, Faletra Francesco F, Sorgente Antonio, Conca Cristina, Moccetti Tiziano, Handschumacher Mark, Brady Thomas J, Hoffmann Udo
Cardiac MR PET CT Program, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
JACC Cardiovasc Imaging. 2008 Nov;1(6):772-81. doi: 10.1016/j.jcmg.2008.07.014.
We sought to determine the feasibility of cardiac computed tomography (CT) to detect significant differences in the extent of left ventricular dyssynchrony in heart failure (HF) patients with wide QRS, HF patients with narrow QRS, and age-matched controls.
The degree of mechanical dyssynchrony has been suggested as a predictor of response to cardiac resynchronization therapy. There have been no published reports of dyssynchrony assessment with the use of CT.
Thirty-eight subjects underwent electrocardiogram-gated contrast-enhanced 64-slice multidetector CT. The left ventricular endocardial and epicardial boundaries were delineated from short-axis images reconstructed at 10% phase increments of the cardiac cycle. Global and segmental CT dyssynchrony metrics that used changes in wall thickness, wall motion, and volume over time were assessed for reproducibility. We defined a global metric using changes in wall thickness as the dyssynchrony index (DI).
The DI was the most reproducible metric (interobserver and intraobserver intraclass correlation coefficients >/=0.94, p < 0.0001) and was used to determine differences between the 3 groups: HF-wide QRS group (ejection fraction [EF] 22 +/- 8%, QRS 163 +/- 28 ms), HF-narrow QRS (EF 26 +/- 7%, QRS 96 +/- 11 ms), and age-matched control subjects (EF 64 +/- 5%, QRS 87 +/- 9 ms). Mean DI was significantly different between the 3 groups (HF-wide QRS: 152 +/- 44 ms, HF-narrow QRS: 121 +/- 58 ms, and control subjects: 65 +/- 12 ms; p < 0.0001) and greater in the HF-wide QRS (p < 0.0001) and HF-narrow QRS (p = 0.005) groups compared with control subjects. We found that DI had a good correlation with 2-dimensional (r = 0.65, p = 0.012) and 3-dimensional (r = 0.68, p = 0.008) echocardiographic dyssynchrony.
Quantitative assessment of global CT-derived DI, based on changes in wall thickness over time, is highly reproducible and renders significant differences between subjects most likely to have dyssynchrony and age-matched control subjects.
我们试图确定心脏计算机断层扫描（CT）检测宽QRS波心力衰竭（HF）患者、窄QRS波HF患者以及年龄匹配对照组左心室不同步程度显著差异的可行性。
机械不同步程度已被认为是心脏再同步治疗反应的预测指标。尚未有关于使用CT评估不同步的发表报告。
38名受试者接受了心电图门控对比增强64层多层螺旋CT检查。从心动周期10%相位增量重建的短轴图像中描绘左心室内膜和外膜边界。评估使用壁厚、壁运动和体积随时间变化的整体和节段性CT不同步指标的可重复性。我们使用壁厚变化定义了一个整体指标作为不同步指数（DI）。
DI是最具可重复性的指标（观察者间和观察者内组内相关系数≥0.94，p<0.0001），并用于确定三组之间的差异：宽QRS波HF组（射血分数[EF]22±8%，QRS 163±28 ms）、窄QRS波HF组（EF 26±7%，QRS 96±11 ms）和年龄匹配对照组（EF 64±5%，QRS 87±9 ms）。三组之间的平均DI有显著差异（宽QRS波HF组：152±44 ms，窄QRS波HF组：121±58 ms，对照组：65±12 ms；p<0.0001），与对照组相比，宽QRS波HF组（p<0.0001）和窄QRS波HF组（p = 0.005）的DI更大。我们发现DI与二维（r = 0.65，p = 0.012）和三维（r = 0.68，p = 0.008）超声心动图不同步有良好的相关性。
基于壁厚随时间变化的整体CT衍生DI的定量评估具有高度可重复性，并显示出最可能存在不同步的受试者与年龄匹配对照组之间的显著差异。
