多巴酚丁胺负荷试验对心肌纵向收缩功能的影响

Effects of dobutamine stress test on the systolic longitudinal myocardial Doppler velocity

目的 :联合使用多巴酚丁胺负荷试验与组织速度成像对局部纵向心肌的收缩功能进行定量分析 ,为临床诊断冠心病和评估存活心肌提供可靠的超声定量方法。方法 :对 18例冠状动脉造影正常或轻度病变和 61例冠心病心肌梗死心功能不全患者进行多巴酚丁胺负荷试验。对正常组和冠心病心肌梗死组基础状态 ,5、10和 2 0 μg/ (kg·min)所测的心肌收缩期峰速度进行统计学分析。结果 :冠脉造影正常组基础状态下 ,各室壁基底部收缩期峰值速度大于心尖部 ,而且呈现一定的规律 ,即基底部大于中部 ,中部又大于心尖部的速度梯度变化 ;侧壁 ,后壁和下壁收缩期峰值速度大于后间隔、前间隔和前壁。其中下、后壁心肌的峰值速度大于其它节段。多巴酚丁胺药物负荷时 ,心肌各节段收缩期峰值速度随着多巴酚丁胺剂量的增加而增加 ,2 0 μg/ (kg·min)收缩期峰值速度达最大值 ;40 μg/ (kg·min)时 ,收缩期峰值速度反而降低。在多巴酚丁胺药物负荷的不同阶段 ,仍然保持基础状态下的速度梯度规律和侧壁 ,后壁和下壁心肌收缩期峰值速度大于后间隔、前间隔和前壁心肌收缩期峰值速度的规律。 5 μg/ (kg·min)时 ,二维超声心动图显示各节段心肌运动无变化 ,但定量负荷显示其心肌收缩峰值速度已明显增加 ,且与基础状态比较差异有显著性意?

Objective:To study regional systolic longitudinal myocardial function quantitatively using tissue velocity imaging (TVI) combined with dobutamine stress echocardiography.Methods:Dobutamine stress echo was performed in 61 patients after coronary angiography, of which 18 revealed normal findings and 43 myocardial infarction.High dose protocol was in normal group (5,10,20,30,40 μg/(kg·min)) and low dose in myocardial infarction (MI) group [5,10, 20 μg/(kg·min)].Commercially available ultrasound machine (VIVID FIVE and VIVID 7,GE medical system) was used for analysis of regional systolic longitudinal myocardial Doppler velocity.Apical 4 chamber view,2 chamber view and long axis view were acquired for each stage.According to Bechmann rule, the systolic peak velocity (SPV) of myocardium was measured in 18 segments in which the middle was the position of sampling.SPV of normal group was compared with MI group in the same segment of each stage.Results:In normal group,the SPV of basal segments was highest,and middle ventricle higher than apical which formed the myocardial velocity gradient,as well as the SPV of lateral,inferior and posterior wall was higher than that of other ventricular wall in baseline and every stage.There was significant difference between the SPV of baseline and each stage in same segment ( P <0.001).The SPV of each segment gradually increased with increasing dobutamine from baseline to 20ug/(kg·min),but it did not significantly increase at 30 and 40ug/(kg·min) of dobutamine. There was very significant difference between the SPV of same segment in normal group and MI group whether it was baseline or every stage. Conclusion:The regional systolic longitudinal myocardial function can be quantitatively evaluated by TVI combined with dobutamine stress echo,which provides a new quantitative method for analysis of regional wall motion abnormality.