256层CTCA结合负荷/静息核素MPI探讨心肌桥对心肌供血的影响

Evaluating the Impact of Myocardial Blood Supply in Myocardial Bridge by a 256 Slice CTCA and MPI

目的应用256层CT冠状动脉成像(CTCA)结合负荷/静息核素心肌灌注显像(MPI)探讨心肌桥(MB)对心肌供血的影响。方法回顾性分析经256层CTCA及负荷/静息核素MPI检查的88例孤立性LAD-MB的影像资料。依据MB类型分为不完全与完全MB组,比较两组壁冠状动脉(MCA)收缩期狭窄率及MPI的差异;比较完全MB中MPI正常与异常组MB厚度、长度及MCA收缩期狭窄率的差异;比较MCA收缩期狭窄Noble分级中MB类型及MPI的差异。结果不同MB类型组MCA收缩期狭窄率分别为(13.2±10.1)%、(39.8±11.4)%,MPI正常与异常分别为45、5例,15、23例,差异有统计学意义(t=11.574;χ2=25.408,P均<0.01)。完全MB中不同MPI组MB厚度分别为(1.6±0.4)mm、(2.6±0.7)mm,MCA收缩期狭窄率分别为(29.3±9.8)%、(46.7±10.3)%,差异有统计学意义(t=5.672;t=5.187,P均<0.01),MB长度分别为(11.2±5.6)mm、(12.8±6.3)mm,差异无统计学意义(t=0.800,P=0.429)。MCA收缩期狭窄Noble分级中2、3级完全MB(15/15、2/2)及MPI异常(10/15、2/2)比例明显高于1级(21/71、16/71)。结论 MB的类型、厚度及MCA收缩期狭窄程度均与心肌缺血密切相关,而MB长度对心肌供血无明显影响。

Objective To evaluate the impact of myocardial blood supply in myocardial bridge by a 256 slice CTCA and MPI. Methods The data of 88 isolated LAD MB patients who had undergone 256 slice CTCA and MPI were collected and analyzed retrospectively. The systolic degrees of stenosis of MCA and MPI were compared between the incomplete and complete MB groups. The MB depth, length and the systolic degree of stenosis of MCA were compared between the normal and abnormal MPI groups. The MB type and MPI were analyzed according to the Noble grade. Results There were sta- tistically significant differences in the systolic degrees of stenosis of MCA and MPI between the incomplete and complete MB groups （ t = 11. 574 ; χ^2= 25. 408 ,P 〈 0.01 ）. A significant difference was not found on the MB length between the normal and abnormal MPI groups（ t =0. 800 ,P = 0. 429） , but significant differences were demonstrated in the MB depth and the systolic degree of stenosis of MCA（t = 5. 672 ;t = 5. 187 ,P 〈 0.01 ）. There was significant correlation between the systolic degree of stenosis of MCA and the MB type myocardial ischemia. Conclusion The MB type, depth and the systolic degree of stenosis of MCA correlate with myocardial ischemia but the MB length does not influence myocardial perfusion.