腺苷负荷实时三维超声心动图对心肌缺血诊断价值的实验研究

Validation of real-time adenosine stress echocardiography for quantifying ischemic myocardium

目的探讨实时三维超声心动图在腺苷负荷试验中对心肌缺血检测的可行性及诊断价值。方法将11只开胸犬先后结扎左冠状动脉前降支（LAD）造成中度心肌缺血及梗死模型，于腺苷负荷试验（140μg·kg^-1·min^-1持续泵入至6min）前后分别记录基础状态、缺血状态、梗死状态下的“金字塔”样左心室三维数据库。结果①左室整体射血分数（EF）在梗死状态下较基础状态及缺血状态均明显减低（P〈0．05），在各个状态下应用腺苷前后差异无统计学意义（P〉0．05）。②LAD节段左室局部参数：与基础状态相比，缺血状态下的局部射血分数（REF）值差异无统计学意义，梗死状态下的REF值显著减低（39％±7％对62％±18％，P〈0．01），局部收缩末期容积（RESV）显著增加[（0．43±0．34）ml对（0．63±0．32）ml，P〈0．013；与缺血状态相比，梗死状态下的REF值显著减低（39％±7％对61％±21％，P〈0．01），RESV显著增加（P〈0．01）；缺血状态下应用腺苷后与用药前相比RESV显著增加（P〈0．01），而REF值显著减低（45％±10％对61％±20％，P〈0．01）。左室同步性分析：与基础状态E（38±27）ms]相比，缺血状态下[（26±8）ms]左室17节段从心电图Q波起始点到最小容积时间的标准差（Ts）的变化无统计学意义，应用腺苷后Ts较用药前显著性增加[（52±11）ms，P〈0．01]，梗死状态下Ts显著增加[（85±7）ms，P〈0．053；与缺血状态相比，梗死状态下Ts显著增加[（85±7）ms，P〈0．01]，而梗死状态下应用腺苷后与用药前相比差异无统计学意义。结论腺苷负荷实时三维超声心动图可以反映缺血心肌局部容积及收缩功能的变化，从而可用于心肌缺血的诊断。

Objective To test the feasibility and accuracy of using real-time three-dimensional echocardiography （RT-3DE） to detect ischemia during adenosine-induced stress. Methods In 11 anesthetized dogs, moderate isehemia was induced by constricting left anterior descending coronary artery （LAD）, and then, LAD was completely occluded to establish infarction models. RT-3DE images were acquired before and after administering adenosine intravenously at a dose of 140 μg · kg^-1· min^-1 for 6 minutes at baseline, during isehemia and infarction. Results As compared with that at baseline and during isehemia, the global ejection fraetion（EF） of left ventricle significantly reduced during infarction（ P 〈 0.05）, while it didn＇t differ significantly after adenosine treatment in each state. In LAD segments, the regional ejection fraetion（REF）, during isehemia, decreased slightly compared with that at baseline, and drastically reduced during infarction （39% ± 7% vs 62% ± 18%, P G0. 01）. Regional end-systolic volume （RESV） increased significantly during infarction（ P 〈0. 01）. Compared with that during ischemia, REF value decreased significantly （39 % ± 7 % vs 61% ±21%, P 〈0.01 ）, whereas RESV increased clearly（ P 〈 0.01 ） during infarction . Changes with adenosine ： during ischemia the REF value significantly reduced in LAD segments after administering adcnosine（45%±10%vs 61%±20% ,P〈0.01）,whilc RESV obviously increased（P〈0.01）.The standand deviation of the time from Q wave to the point of minimal systolic volume（Ts）in 17 scgments was compared botween unch stme.Compared with that ot boschine[（38±27）ms],the Ts value didn＇t change significantly during ischcmin [（26±8）ms],whereas significantly incteused after adenosine administration[（52±11）ms,P〈0.001].Compared with that at bascline and during ischemia.the Ts value increased clearly during infaretion [（85±7）ms,P〈0.05]and [（85±7）ms,p〈0.01]but did not change with adenosine treatment,Conclusions Adenosine stress RT-3DE is fonstihle and sensitive in detecting ischemic myocardium and is capable of measuring global and regional volume and systolic function of left ventriclc.