应用定量组织速度成像技术结合小剂量多巴酚丁胺负荷试验诊断冠心病

Quantitative tissue velocity imaging technique for diagnosis of coronary artery disease during low-dose dobutamine stress echocardiography

目的 探讨应用定量组织速度成像 (QTVI)技术结合小剂量多巴酚丁胺负荷超声心动图试验(LDDSE)诊断冠心病的价值。方法 对经冠状动脉造影证实的 3 0例冠心病患者及 10例正常人进行LDDSE检查。应用QTVI技术分别同步获取各受检者在LDDSE前后室间隔和左室下壁的二尖瓣瓣环、基底部、中部及心尖部 4个不同取样点心肌组织的时间 速度曲线 ;根据各曲线分别测量出同一室壁各取样点从心电图R波到舒张早期心肌峰值速度的时间 ,计算它们之间的最大差值 (dTRE) ;测量出从心电图R波到心房收缩期心肌峰值速度的时间 ,计算它们之间的最大差值 (dTRA)。结果 小剂量 (10 μg·kg-1·min-1)多巴酚丁胺负荷超声心动图试验时 ,左前降支病变患者的室间隔dTRE较静息状态时明显升高 [(4 8± 19)ms对 (2 1± 10 )ms ,P <0 .0 1] ;右支病变患者的左室下壁dTRE较静息状态时明显升高 [(5 2± 17)ms对 (2 3± 10 )ms ,P <0 .0 1] ;双支病变患者的室间隔及左室下壁dTRE较静息状态时均明显升高 [室间隔 :(4 9± 15 )ms对 (2 2± 8)ms ,P <0 .0 1;左室下壁 :(5 4±12 )ms对 (2 1± 15 )ms ,P <0 .0 1] ;正常对照组室间隔及左室下壁的dTRE较静息状态时均无明显改变。以dTRE>3 5ms作为截断值诊断冠心病的敏感性为 85 % ,特异性为 89%。

Objective To clarify feasibility for diagnosing coronary artery disease by quantitative tissue velocity imaging(QTVI) technique during low-dose dobutamine stress echocardiography(LDDSE).Methods LDDSE was performed on thirty patients with coronary artery disease and ten age-matched healthy subjects.Twenty-one patients had either left anterior descending coronary artery(LAD) disease( n =13) or right coronary artery(RCA) disease( n =8),and 9 had both LAD and RCA lesions(2-VD).Apical 4- and 2-chamber views were obtained by tissue velocity imaging before and during LDDSE.The maximal differences of time intervals from R-wave on electrocardiogram to peak of early diastolic myocardial velocity(dT RE )in the same cardiac cycle among mitral annular and basal,mid and apical segment in the septal and inferior wall were measured.Results During low-dose(10 μg·kg -1 ·min -1 ) dobutamine stress echocardiography,dT RE of septum in LAD disease [(48±19)ms vs (21±10)ms, P < 0.01 ] and dT RE of inferior wall in RCA disease [(52±17)ms vs (23±10)ms, P < 0.01 ] were prolonged.In 2-VD,prolongation of dT RE of both septum and inferior wall were observed [septum:(49±15)ms vs (22±8)ms, P < 0.01 ];inferior wall:[(54±12)ms vs (21±15)ms, P < 0.01 ].The sensitivity and specificity of dT RE >35 ms for diagnosing coronary artery disease were 85% and 89%,respectively.Conclusions Observing the regional diastolic asynchrony determinated by QTVI can diagnose coronary artery disease during LDDSE.