高血压早期心肌应力及细胞外间质容积的动物实验研究  

An animal experiment on myocardial stress and extracellular volume in early hypertension

作　　者：庄白燕 崔辰 何健 王学民 王欣 段雪晶 王红月 赵世华 陆敏杰 ZHUANG Bai-yan;CUI Chen;HE Jian(Chinese Academy of Medical Sciences Fuwai Hospital,National Center for Cardiovascular Diseases,Peking Union Medical College,State Key Laboratory of Cardiovascular Diseases,Beijing 100037,China)

机构地区：[1]中国医学科学院阜外医院,国家心血管病中心,北京协和医学院,心血管疾病国家重点实验室,北京100037 [2]中国医学科学院,心血管影像重点实验室(培育),北京100037

出　　处：《放射学实践》2020年第7期865-872,共8页Radiologic Practice

基　　金：国家自然科学基金(81571647,81771811,81971588);首都临床特色项目基金(Z191100006619021);中国医学科学院重点实验室建设期项目(2019PT310025);中国医学科学院临床与转化基金(2019XK320063);中国医学科学院北京协和医学院研究生教育教学改革基金(10023201900204)。

摘　　要：目的:以病理为金标准,联合应用心脏磁共振特征追踪(CMR-FT)及T 1-mapping评估高血压早期心脏结构、功能及心肌组织特征改变。方法:对18头健康中国雄性小型猪进行前瞻性研究,实验组(12头)通过结扎左肾动脉建立高血压模型,对照组(6头)同样开腹但不结扎动脉。两组在基线、造模后6月进行3.0T心脏磁共振检查,通过电影序列计算心肌应变指标和心功能参数,通过T 1-mapping计算细胞外间质容积分数(ECV),并且进行心脏磁共振晚期钆对比剂增强检查(LGE)。第2次MRI检查后处死动物,进行TTC大体染色和苏木精-伊红(HE)、Masson、天狼星红染色。结果:建模后6个月高血压组平均收缩压/舒张压由102/71 mmHg逐渐升高至145/86 mmHg。造模前、后左心室射血分数没有显著差异(P=0.34),LGE在基线、造模后6个月均为阴性。高血压组心肌的径向应力(RS)、纵向应力(LS)、周向舒张早期应变率(CSRE)及纵向舒张早期应变率(LSRE)显著降低(P<0.05)。造模6个月后HE、Masson、天狼星红染色切片显示左心室心肌出现明显的间质纤维化。胶原纤维体积分数(CVF)与RS具有良好的相关性(r=-0.61,P=0.03)。ECV从21.7%增加到29.2%(P=0.03),且与RS(r=-0.74,P=0.01)、LSRE(r=-0.92,P<0.001)及CSRE(r=-0.65,P=0.02)均呈负相关。结论:CMR-FT比射血分数更敏感地评估高血压早期心脏功能的受损程度,并且这一改变与心脏细胞外间质纤维化增多有关。Objective:To evaluate the changes in cardiac structure,function,and myocardial tissue characteristics in the early stages of hypertension confirmed by pathology by the combination of cardiac magnetic resonance-feature tracking(CMR-FT)and T 1-mapping.Methods:Eighteen healthy Chinese male miniature pigs aged 6~12 months were included in the prospective study.In the hypertension group(N=12),the left renal artery was ligated to obtain a chronic hypertension model,while the control group(N=6)did the laparotomy without ligation.The two groups underwent cardiac MRI at baseline and 6 months after modeling.Strain,strain rate and cardiac function parameters were calculated by cine MRI,extracellular volume fraction(ECV)was calculated by T 1-mapping,and late gadolinium enhancement(LGE)was performed.After the second MRI,the animals were sacrificed for TTC staining and hematein eosin(HE),Masson and Picrosirius staining.Results:The mean systolic/diastolic blood pressure increased gradually from 102/71mmHg to 145/86mmHg during 6 months after modeling.There was no significant difference in left ventricular ejection fraction between different periods of hypertension(P=0.34).LGE was negative at baseline and 6 months after modeling.In the hypertensive group,the radial strain(RS),longitudinal strain(LS),circumferential early diastolic strain rate(CSRE)and the longitudinal early diastolic strain rate(LSRE)were significantly decreased(P<0.05).HE,Masson and Picrosirius staining sections showed obvious interstitial fibrosis in myocardium 6 months after modeling.There was a good correlation between CVF and RS(r=-0.61,P=0.03).ECV increased with modeling time(from 21.7%to 29.2%,P=0.03).ECV was negatively correlated with the RS(R=-0.74,P=0.01),and negatively correlated with LSRE(R=-0.92,P<0.001),and CSRE showed a negative correlation with ECV(R=-0.65,P=0.02).Conclusion:CMR-FT is more sensitive than EF in assessing the degree of impaired cardiac function in early hypertension,and this change is associated with increased cardiac interstitial f

关 键 词：心脏磁共振成像 特征追踪 应力 应变率 左心室 心肌纤维化 细胞外间质容积分数 

分 类 号：R445.2[医药卫生—影像医学与核医学] R544.1[医药卫生—诊断学]