心脏MR左室流出道解剖学参数与梗阻性肥厚型心肌病心肌纤维化的相关性分析

Correlation analysis between anatomical parameters of left ventricular outflow tract and myocardial tissue characteristics in obstructive hypertrophic cardiomyopathy

目的探讨梗阻性肥厚型心肌病(HOCM)心脏磁共振(CMR)左室流出道(LVOT)舒张末期(ED)和收缩末期(ES)解剖学参数与心肌组织特征的相关性。方法回顾性收集34例HOCM和54例正常对照组的CMR资料。解剖学参数包括部分二尖瓣前叶长度(PAMLL)、总二尖瓣前叶长度(TAMLL)、ED及ES LVOT直径(LVOTED、LVOTES)、基底部前室间隔厚度(BAISED、BAISES)、主动脉瓣下直径(SADED、SADES)。心肌组织参数包括细胞外容积比例(ECV)和延迟强化负荷(LGE%)。结果HOCM的LVOT解剖学参数在ED和ES与对照组均有差异(P<0.05)。在HOCM中,TAMLL与ECV呈正相关(P=0.038),BAISED与LGE%呈正相关(P=0.001);ES参数均与ECV和LGE%无相关性(P>0.05)。多因素回归分析提示TAMLL是ECV值的独立预测因子,线性公式为ECV=19.37+0.24×TAMLL,提示TAMLL增加1 mm,ECV增加0.24%;BAISED是LGE%的独立预测因子,线性公式为LGE%=-24.24+1.42×BAISED,表明BAISED增加1 mm,LGE%增加1.42%。结论HOCM的LVOT解剖学参数中,TAMLL、BAISED对心肌组织病变程度有一定的预测价值。

Objective To investigate the correlation between natomic parameters of the left ventricular outflow tract(LVOT)during end-diastole(ED)and end-systole(ES),as well as characteristic parameters of myocardial tissue in obstructive hypertrophic cardiomyopathy(HOCM),using cardiac magnetic resonance(CMR).Methods Thirty-four patients with HOCM and fifty-four healthy controls were retrospectively included.CMR data included partial anterior mitral leaflet length(PAMLL)and total anterior mitral leaflet length(TAMLL).At ED and ES,various parameters were assessed,including the diameter of the left ventricular outflow tract(LVOTED,LVOTES),thickness of the basal anterior interventricular septum(BAISED,BAISES),and subaortic diameter(SADED,SADES).Additionally,myocardial tissue characterization imaging parameters including extracellular volume fraction(ECV)and the percentage of late gadolinium enhancement(LGE%)were analyzed.Results Anatomic parameters of LVOT at two phases in HOCM patients differed significantly from those in the control group(P<0.05).In HOCMs,TAMLL was positively correlated with ECV(P=0.038),and BAISED was positively correlated with LGE%(P=0.001).Multivariable analysis indicates that TAMLL is an independent predictor of ECV,with the linear equation ECV=19.37+0.24×TAMLL,suggesting that a 1 mm increase in TAMLL was associated with a 0.24%increase in ECV;while BAISED ndependently predicted LGE%,with the linear equation LGE%=-24.24+1.42×BAISED,suggesting that a 1 mm increase in BAISED corresponded to a 1 mm increase and a 1.42%increase in LGE%.Conclusion The LVOT anatomical parameters of HOCMs,namely TAMLL and BAISED,exhibit significant correlations with the myocardial tissue characterization imaging parameters and possess a certain predictive value for assessing the extent of myocardial tissue changes.