心率对左心功能指数、主动脉强化CT值及延迟时间的影响

The effect of heart rate on left cardiac function index,enhanced CT value of aorta and delay time

目的：探讨心率对左心功能指数、主动脉强化CT值和延迟时间的影响。方法：连续选择进行冠状动脉CTA的患者74例，在对比剂注射参数相同的情况下，按照心率分为低心率组（≤75a／分）和高心率组（〉75次／分）。所得数据在0％～90％R-R间期以10％为间隔进行重组，分析心输出量、每搏输出量和射血分数，测量两组主动脉强化CT值和延迟时间。并对两组间的差异进行统计学分析。结果：在对比剂注射参数相同的情况下，高心率组心输出量高于低心率组（t=3．908，P〈0．05），但高心率组主动脉强化CT值和延迟时间均低于低心率组（t=2．536，3．454，P均〈0．05）。结论：掌握不同心率下心功能指数、主动脉强化CT值及延迟时间的变化有助于冠状动脉CTA扫描中对比剂注射参数的设定，获得优良的图像质量。

Objective：The purpose of this study was to evaluate the effect of heart rate （HR） on left cardiac function index, enhanced CT value of aorta and delay time. Methods：Seventy-four consecutive patients underwent dual-source CT angiography using the same parameters for contrast administration. Patients were divided into slow HR groups （≤75bpm） and fast HR groups （〉75bpm）. All of the original data were reconstructed at 0% -90% R-R interval with 10% interval and the cardiac output,stroke volume and ejection fraction were analyzed. The enhanced CT value of aorta and delay time were measured. Statistical analyses were performed between the two groups. Results： Using the same parameters for contrast administration,the cardiac output of the fast HR group was higher than that of slow HR group, with significant difference （t=3. 908,P〈0.05）. Yet the enhanced CT value of aorta and delay time were lower in fast HR group compared with that of slow HR group （t= 2. 536,3. 454;P〈0.05）. Conclusion： Well knowledge about the variation of cardiac function index, enhanced CT value of aorta and delay time with different HR is very useful for designing contrast medium injection parameters and obtaining excellent image quality.