二维斑点追踪技术早期评价放射性心脏病兔左室舒张功能的价值

Two-dimensional speckle tracking early predicts ventricular diastolic function in rabbits with radiation induced heart disease

目的:探讨二维斑点技术早期评价放射性心脏病兔左室舒张功能的价值。方法:采用单次40 Gy(高剂量组,n=10)、20 GY(低剂量组,n=12)、0 GY(对照组,n=7)剂量照射兔心脏建立模型;于放疗前(T0期)、放疗后第0周(T1期)、放疗后第5周(T2期)、放疗后第15周(T3期)和放疗后第25周(T4期)对兔进行超声检测,比较三组左心室舒张功能;在T0~T3期2D-STI完成后随机选取高剂量组2只和低剂量组2只、对照组1只兔子处死,T4期超声完成后处死所有兔子,进行病理组织学观察。结果:组间比较,T3、T4期高剂量组整体纵向舒张早期应变率降低,差异有统计学意义(P<0.05);T4期高剂量组整体纵向舒张晚期应变率增大,差异有统计学意义(P<0.05);T0~T4期低剂量组整体纵向舒张早期应变率、整体纵向舒张晚期应变率差异无统计学意义(P>0.05)。组内比较,高剂量组整体纵向舒张早期应变率从T2~T4期逐渐降低,整体纵向舒张晚期应变率T4期增大,差异有统计学意义(P<0.05)。低剂量组整体纵向舒张早期应变率及整体纵向舒张晚期应变率差异无统计学意义(P>0.05)。结论:二维斑点追踪技术可早期评价放射性心脏病兔左心舒张功能,放射剂量越大,观察时间越长,心功能损伤表现越明显。

Objective:To explore the value of two-dimensional speckle tracking technology in early detect left ventricular diastolic function of radiation induced heart disease rabbits.Methods:Single doses of 40 Gy(high dose group),20 Gy(low dose group)and 0 Gy(control group)were used to irradiate the heart of rabbits to establish the model.The left ventricular diastolic function of the three groups was compared by 2 D-STI detection before radiotherapy(T0),0 week after radiotherapy(T1),5 week after radiotherapy(T2),15 week after radiotherapy(T3),and 25 week after radiotherapy(T4).After the completion of 2 D-STI in stage T0-T3,2 rabbits in the high-dose group and 2 rabbits in the low-dose group,and 1 rabbit in the control group were randomly selected and dissected.After the completion of 2 D-STI in stage T4,all rabbits were dissected for histological observation.Results:Compared between groups,the Left global diastolic strain rate(LGSRE)in the high-dose groups at T3 and T4 stage decreased,with statistical significance(P<0.05).Left global ventricular late diastolic strain rate(LGSRA)in the high-dose groups increased at the T4 stage,and the difference was statistically significant(P<0.05).There was no significant difference in LGSRE and LGSRA in the low-dose groups at T0-T4(P>0.05).Within groups,LGSRE in the high-dose group gradually decreased from T2-T4 stage and LGSRA increased at T4 stage,with statistical significance(P<0.05).There was no significant difference in LGSRE and LGSRA in the low-dose group(P>0.05).Conclusion:2 D-STI can be used for early evaluation of left ventricular diastolic function in RIHD rabbits.The higher the radiation dose,the longer the rabbits observed,the more obvious damage the cardiac function have.