卡维地洛对慢性心力衰竭兔心肌应变及应变率的影响

Effect of Carvedilol on Strain and Strain Rate in Rabbits with Chronic Heart Failure

关键词:  应变率成像  慢性心力衰竭  多普勒超声心动描记术；β-肾上腺素能受体拮抗剂

Key words:  strain rate imaging (SRI)  chronic heart failure  doppler echocardiography  β-adrenocepter blocker

摘要:

目的探讨卡维地洛对慢性心力衰竭兔心肌应变及应变率的作用，以评价其对心肌局部功能的影响和意义。方法30只日本大耳兔随机分为3组，分别为空白对照组（CTL组，6只）、慢性心力衰竭组(CHF组，12只)和卡维地洛干预心衰组（CVD组，12只）。CHF组和CVD组兔每周2次耳缘静脉注射盐酸阿霉素溶液（浓度：1 mg·mL-1）1 mL·kg-1，共计8周；对照组同期耳缘静脉注射等量生理盐水。对照组和模型组兔自第12周始每日以生理盐水（5 mg·kg-1·d-1）灌胃，CVD组兔以等量卡维地洛生理盐水（浓度:1 mg·mL-1）灌胃，共8周。分别于第12，20周测定3组兔血清B型钠尿肽（BNP）水平，心脏超声测定左心室舒张末期内径（LVEDD）、左室射血分数（LVEF）和缩短分数（FS）等，同时应用心肌应变率显像（SRI）技术检测3组兔左室侧壁和室间隔基底部心肌的收缩期和舒张早期峰值应变率 (SRs和SRe)、收缩期和舒张期峰值应变 (PSS和PDS)的变化。结果①CHF组和CVD组兔在12周时，其血清BNP水平较CTL组明显升高、LVEDD扩大、LVEF和FS下降，左室侧壁和室间隔基底部心肌SRs，SRe，PSS，PDS明显降低。②20周时，CVD组兔较12周时血清BNP水平和LVEDD明显下降、LVEF和FS明显升高，SRs，SRe，PSS，PDS显著增高；CHF组和对照组上述指标与第12周比较无明显变化。结论慢性心衰时局部心肌收缩期和舒张期峰值应变和应变率降低；卡维地洛可以改善心力衰竭兔整体心肌收缩功能、改善心脏重构；也可以增加收缩期和舒张期峰值应变及应变率，改善局部心肌收缩和舒张功能。

Abstract:

OBJECTIVE To investigate the effect of carvedilol on myocardial strain and strain rate and to evaluate its roles and significance on regional myocardial function in rabbits with chronic heart failure. METHODS Thirty Japanese rabbits were randomly devided into 3 groups: control (CTL group,n=6), chronic heart failure group (CHF group,n=12) and carvedilol-intervened group (CVD group，n=12). Rabbits in CHF and CVD group were intravenously injected at auri-edge with adriamycin hydrochloride twice a week for 8 weeks with a concentration of 1 mg·kg-1, the CTL group was injected with equal saline at the same timepoint. Thereafter, rabbits in CTL and CHF group were administrated ig with 5 mg·kg-1·d-1 saline , and CVD group with equal volume of carvedilol-saline, daily for 8 weeks. The serum B-type natriuretic peptide (BNP) level in 3 group of rabbits were detected on week 12 and week 20, respectively.Meanwhile, the left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF) and fractional shortening (FS) were measured by echocardiography, the peak systolic and peak diastolic strain (PSS and PDS), the systolic and early diastolic strain rate (SRs and SRe) derived from the basal segment of inter-ventricular septum (BS-IVS) and left ventricular lateral wall (LVLW) were assessed by strain rate imaging. RESULTS In comparison with CTL group, the serum BNP level and LVEDD in CHF and CVD group of rabbits were significantly increased, while the LVEF, FS, SRs,SRe, PSS and PDS of BS-IVS and LVLW were significantly decreased on week 12. In CVD group, the serum BNP level, the LVEDD on week 20 were significantly decreased in comparison with those on week 12, while the LVEF, FS , SRs、SRe、PSS and PDS were significantly increased.While in CTL and CHF groups, there was no significant change in above parameters. CONCLUSION The systolic and peak diastolic strain and strain rate of regional myocardium were decreased in chronic heart failure.Carvedilol can improve the global systolic function and cardiac remodeling in chronic heart failure rabbits and can also increase the systolic and peak diastolic strain and strain rate thus improve regional myocardial function.