磁共振定量技术评价心肌炎患者双室心肌应变功能的初步临床研究

Quantitative assessment of double ventricular strain in patients with myocarditis using cardiovascular magnetic resonance feature tracking techniques:a preliminary clinical study

目的:基于心脏磁共振(CMR)特征组织追踪技术定量评估心肌炎患者和健康对照者左右室不同方向心肌应力值,并结合临床指标分析心肌炎患者相关磁共振定量参数异常的影响因素。方法:对40例心肌炎患者及30例健康志愿者行1.5T CMR检查,将心脏电影离线导入组织追踪应力分析后处理软件,半自动计算左右室心肌收缩峰值纵向应力(GLS)、左室心肌收缩峰值周向应力(GCS)、左室心肌收缩峰值径向应力(GRS)以及相应方向心肌应力率。行CMR检查前,收集心肌炎患者基线临床数据以及相关血生化指标。行数据分析时,将心肌炎患者依据其左室射血分数(LVEF)值的大小分为LVEF≥50%和LVEF<50%两组。结果:心肌炎患者LVEF<50%组的LVGLS、LVGCS、LVGRS及RVGLS值均低于心肌炎LVEF≥50%组和正常对照组[LVGLS:(-7.7±4.3)%、(-13.1±2.0)%、(-15.2±2.0)%;LVGCS:(-10.1±4.6)%、(-19.8±1.9)%、(-21.5±2.2)%;LVGRS:(13.1±8.3)%、(30.9±4.3)%、(38.5±9.1)%;RVGLS:(-15.9±5.3)%、(-19.6±4.8)%、(-19.8±3.5)%;P<0.05];心肌炎患者LVEF≥50%组的LVGLS、LVGRS值低于正常对照组[LVGLS:(-13.1±2.0)%、(-15.2±2.0)%,P<0.05;LVGRS:(30.9±4.3)%、(38.5±9.1)%,P<0.01]。心肌炎患者组的血尿素氮(BUN)值、肌酐(CREA)值与LVGLS、LVGCS、LVGRS值分别呈负相关(P<0.05);血B型钠尿肽(BNP)值与LVGLS、LVGCS、LVGRS及RVGLS值分别呈负相关(P<0.01);血C反应蛋白(CRP)值与LVGRS值呈负相关(P<0.05)。结论:心肌炎患者左右室心肌应变功能均受损,且在左室收缩功能尚未受损时左室心肌应变已出现减低,心肌应力值的改变与临床炎症指标、心功能、肾功能的异常具有相关性。

Objective:The present study aims to assess the double ventricular myocardial systolic strain in patients with myocarditis using cardiac magnetic resonance feature-tracking(MR-FT)and their underlying relationships with clinical parameters.Method:We recruited 40 patients with myocarditis and 30 healthy volunteers to undergo CMR examinations.Then we used the routine cine images and MR-FT to analyze the double ventricular myocardial global systolic strain and the strain rates.The patients were divided into two groups according to the left ventricular ejection fraction(LVEF)(group 1-LVEF≥50%,group 2-LVEF<50%).Before the CMR examination,we collected the baseline clinical and biochemical indices.Result:The values of LVGLS,LVGCS,LVGRS and RVGLS were significantly lower in the myocarditis group(LVEF<50%)than those in the group(LVEF≥50%)and control group[LVGLS:(-7.7±4.3)%,(-13.1±2.0)%,(-15.2±2.0)%;LVGCS:(-10.1±4.6)%,(-19.8±1.9)%,(-21.5±2.2)%;LVGRS:(13.1±8.3)%,(30.9±4.3)%,(38.5±9.1)%;RVGLS:(-15.9±5.3)%,(-19.6±4.8)%,(-19.8±3.5)%;P<0.05].The values of LVGLS,LVGRS were lower in the myocarditis group(LVEF≥50%)than those in control group[LVGLS:(-13.1±2.0)%,(-15.2±2.0)%,P<0.05;LVGRS:(30.9±4.3)%,(38.5±9.1)%,P<0.01].In the myocarditis group,the values of LVGLS,LVGCS and LVGRS had negative correlations with the BUN,CREA levels(P<0.05);the values of LVGLS,LVGCS,LVGRS and RVGLS had negative correlations with the BNP level(P<0.01);the value of LVGRS had a negative correlation with the CRP level(P<0.05).Conclusion:Our results suggested that the left and right ventricular systolic function and systolic strain were impaired in the LVEF<50%group.The left ventricular systolic strain was impaired in the LVEF≥50%group either.We also found that there were negative correlation between the BUN,CREA,BNP,CRP levels and the left and right ventricular strain in patients with myocarditis.