多巴酚丁胺负荷试验对原发性扩张型心肌病心室同步性影响的研究

Study of dobutamine stress with Doppler tissue imaging echocardiography on synchronism of electromechanical activity in idiopathic dilated cardiomyopathy

目的 探讨多巴酚丁胺对原发性扩张型心肌病(DCM)电机械活动同步性的作用。方法 18例DCM患者应用多巴酚丁胺超声心动图负荷试验(DSE)并结合心肌组织多普勒成像技术(DTI),分别于基础状态和多巴酚丁胺剂量为5、10、20μg·kg-1·min-1时测量左侧房室环左室电机械活动时间离散度(校正EM D)、左室心肌运动速度差(Sm D)和血流动力学等指标。结果 校正EM D和Sm D在基础状态和不同剂量多巴酚丁胺负荷时差异均无显著性意义(P>0. 05);血流动力学指标在负荷前后有显著变化(P<0. 05)。结论 多巴酚丁胺在改善DCM血流动力学的同时,没有恶化左心室电机械活动的同步性和心肌运动的同步性。

Objective To investigate whether dobutamine could induce or worsen electromechanical activity synchronism in the patients with idiopathic dilated cardiomyopathy(DCM). Methods Eighteen patients with DCM[mean age ( 45.8 ± 13.9 ) years, NYHA class Ⅱ-Ⅲ, left ventricular ejection fraction(LVEF)<40%] underwent low dose dobutamine stress echocardiography (5,10,20 μg·kg -1 ·min -1 ). The peak systolic velocity (Sm) in left side atrioventricular annulus was recorded with Doppler tissue imaging(DTI) mode during rest and each stage of dobutamine infusion. Electromechanical dispersion(Em D) which resembles left ventricular(LV) electromechanical synchronism, the means of Sm(Sm M) and the difference between the maximal and minimal myocardial tissue motion velocities(Sm D) were measured. Hemodynamic indexes including LV systolic and diastolic end volume, the peak velocities of aortic flow, LVEF, CO and Z ratio were also measured. Results EM D changed from( 0.05 ± 0.08 )ms at the rest to( 0.06 ± 0.06 )ms, ( 0.06 ± 0.07 )ms and ( 0.06 ± 0.06 )ms during the periods of 5,10,20 μg·kg -1 ·min -1 dobutamine infusion (F= 0.588 , = 0.627 ) respectively, Sm D changed from ( 2.2 ± 1.1 )cm/s to ( 2.2 ± 1.4 )cm/s, ( 2.4 ± 1.6 )cm/s, ( 3.8 ± 1.5 )cm/s (F= 0.304 , P= 0.823 ). Sm M, LVEF and CO increased (P< 0.05 ), all of the corrected ED, AD, LVFT,LVET, IVRT, and Z ratio showed no statistical difference. Conclusions With the hemodynamic improvement,dobutamine could neither worsen nor improve the synchronism of the mechanical activity or coordination of LV in DCM patients.