冠状动脉储备功能与左心功能变化在左乳内动脉原位转流术中的应用价值

Research of coronary reserve function and left ventricular function in patients undergoing in-situ left internal mammary coronary artery bypass grafting

目的探讨左心功能相关指标与冠状动脉储备功能在左乳内动脉原位转流术中的应用价值。方法选取采用左乳内动脉作为桥血管进行冠状动脉旁路移植术患者50例,术前1周及术后1个月超声检查评估患者左乳内动脉及心脏相关指标,观察左心室壁运动情况并进行评分,同时利用斑点追踪技术采集左心室壁各阶段径向应变(RS)及径向应变率(RSr)。小剂量多巴酚丁胺负荷超声心动图(LDDSE)检查后重复上述操作。结果患者术前、术后超声检查均能清晰显示左乳内动脉管腔及血流情况,左乳内动脉频谱由术前收缩期优势型转变为术后舒张期优势型频谱,为低阻力血流,术后乳内动脉起始段的显示率为100%,内径较术前增宽,PSV及PDV较前增加,阻力指数减低,且术后舒张期流速时间积分及舒张期流速时间积分分数明显增加。乳内动脉-左侧锁骨下动脉夹角与术中桥血管流量呈负相关,术后1个月桥血管流量较术中流量明显增加。左乳内动脉原位转流术患者存活心肌静息及负荷状态RS、RSr低于非存活心肌,存活心肌、非存活心肌静息状态RS、RSr高于负荷状态。结论超声心动图可评估短期桥血管的通畅程度,分析影响桥血管流量的因素,斑点追踪技术联合小剂量多巴酚丁胺负荷检查可有效区分心肌梗死中存活心肌与非存活心肌。

Objective To investigate the value of left heart function-related indexes and coronary artery reserve in left internal mammary artery in situ bypass grafting.Methods Fifty patients were selected for coronary artery bypass grafting using the left internal mammary artery as the bridge vessel.The left internal mammary artery and cardiac-related indexes were assessed by ultrasound 1 week before and 1 month after surgery,and the left ventricular wall motion was observed and scored,while radial strain(RS)and radial strain rate(RSr)were collected at each stage of the left ventricular wall using speckle tracking technique.These were repeated after a low-dose dobutamine load.Results The lumen and blood flow of the internal mammary artery were clearly demonstrated by preoperative and postoperative ultrasound examinations of the patients.The spectrum of the internal mammary artery changed from the preoperative systolic dominant type to the postoperative diastolic dominant type spectrum,which was low resistance flow,and the display rate of the beginning segment of the internal mammary artery was 100%after surgery,the inner diameter was wider than before,the PSV and PDV were increased than before,the resistance index was reduced,and the diastolic flow velocity time integral and diastolic flow the diastolic flow time integral and diastolic flow time integral scores were significantly increased after surgery.The resting and loading state RS and RSr were lower in surviving myocardium than in non-surviving myocardium,and the resting state RS and RSr were higher in surviving myocardium and non-surviving myocardium than in loading state in patients with left internal mammary artery in situ diversion.Conclusion Echocardiography can assess the patency of short-term bridge vessels and analyze the factors affecting bridge vessel flow,and the speckle tracking technique combined with low-dose dobutamine loading examination can effectively differentiate between surviving and non-surviving myocardium in myocardial infarction.