心肌存活性对冠状动脉旁路移植术左心整体功能的影响

The effect of myocardial viability on left ventricular global function:a continuous observation using echocardiography

目的 探讨行冠状动脉旁路移植术 (CABG)的冠心病患者术前运动异常心肌的收缩功能储备对术后左心整体功能的影响。方法 超声心动图连续观察 65例冠心病患者术前静态、小剂量多巴酚丁胺 [5～ 10 μg/(kg·min) ]和术后的左心功能改变。 结果 有收缩功能储备组 (Ⅱ组 )的EDV、EDVI、ESV、ESVI明显高于无收缩功能储备组 (Ⅰ组 ) (P <0 .0 1) ,EF明显低于Ⅰ组。LDDSE时Ⅰ组的ESV、ESVI明显减少 ,EF、SV、CO、CI明显增加 ;Ⅱ组除HR轻度增加外 ,其余指标无变化。CABG术后 ,Ⅰ组的EDV、EDVI、ESV、ESVI比静息时明显减少 (P <0 .0 0 1) ,EF、CO、CI明显增加 ;且术后EDV、EDVI比LDDSE时也明显减少。Ⅱ组术后除HR比术前静态时增加外 ,其余指标与静态和LDDSE均无变化。术后Ⅰ组和Ⅱ组相比 ,Ⅱ组EDV、EDVI、ESV、ESVI仍明显高于Ⅰ组 ,EF明显低于Ⅰ组 ,但与术前相比统计学差异更为显著 (P <0 .0 0 1)。结论 运动异常节段的存活心肌对血运重建术后心脏整体功能的恢复起着重要作用。有收缩功能储备时 ,LDDSE提高EF、SV、CO、CI等整体心功能指标的途径是减少ESV、ESVI而保持EDV、EDVI不变。如左心EDV、ESV均增大且无存活心肌时 ,术后整体心功能可能改善不明显。

Objective To evalutate the effect of myocardial viability on left ventricular global function in patients referred to CABG.Methods Echocardiography was performed during preoperation,Low dose dobutamine stress and post operation in 65 patients.Results EDV,EDVI,ESV,ESVI were significantly higher and EF were lower in group Ⅱ(contractile reserve) than in group Ⅰ(no contractile reserve) preoperatively.During LDDSE,ESV and ESVI were reduced and EF,SV,CO,and CI were increased significantly in group Ⅰ.However,there were no change of the other parameters in group Ⅱ except HR which was increased.After operation,EDV,EDVI,ESV,and ESVI were reduced and EF,CO,and CI were increased significantly compared with preoperation (P< 0.001 ).EDV and EDVI were also significantly reduced compared with LDDSE.In group Ⅱ,there were no significant changes of these indexes.After operation,EDV,EDVI,ESV and ESVI were still higher and EF was lower in group Ⅱ than those in group Ⅰ,but there was more significance between the two groups (P< 0.001 ).Conclusions Viable myocardium in asynergic segments is of vital importance in the recovery of global left ventricular function after revascularization.This study implied that in patients with contractile reserve,the increment of EF,SV,CO,and CI depends on reducing ESV and ESVI and maintaining EDV and EDVI unchanged.If EDV and ESV significantly were increased and there was no myocardial viability,the global LV function may not be improved after bypass operation.