Application Of Myocardial Strain In The Evaluation Of Left Ventricular Function In Hypertrophy Cardiomyopathy

OBJECTIVES:To investigate the relationship between myocardial strain of left ventricle,myocardial hypertrophy and late gadolinium enhancement(LGE),and evaluate the application of myocardial strain in the evaluation of left ventricular function in hypertrophy cardiomyopathy(HCM).METHODS : Cardiac magnetic resonance imaging exam were performed sequentially on 56 sequential enrolled hypertrophy cardiomyopathy patients with left ventricular ejection fraction preserved,another 30 healthy volunteers were scaned by MRI as the control arm.Baseline datas,such as left ventricular eject fraction,left ventricular end diastolic volume,left ventricular mass,left ventricular end diastolic volume index,left ventricular mass index were collected and compared.Global Longitudinal Strain(GLS),Global Radial Strain(GRS),Global Circumferential Strain(GCS)were measured and compared by CVI42 software.Regional hypertrophy,late gadolinium enhancement and strain according to American Heart Association(AHA)17-segment model were also estimated.RESULTS:A total of 896 segments in 56 patients according to the AHA 17-segment model were collected for analysis.Myocardial hypertrophy were found in 175segments(19.5%),while ventricular septum was the most commonly involved(9,3,8,14,2,13 segments).LGE was also most commonly implicated in ventricular septum.Left ventricle GLS,GRS,GCS were significantly decreased(P<0.05)in HCM compared with healthy volunteers.Regional radial strain and circumferential strain in HCM were significantly decreased(P<0.05)compared with healthy volunteers.The decreases were found both in hypertrophic segments and non-hypertrophic segments(P<0.05).Regional strain in segments with or without LGE were also significantly decreased(P<0.05).CONCLUSIONS:Under the condition that left ventricular ejection fraction were preserved,global and regional myocardial strain of left ventricle in HCM patients decreased significantly compared to healthy volunteers.Regional strain were decreased despite the existence of segmental myocardial hypertrophy and late gadolinium enhancement,suggesting that the decrease of myocardial strain was correlated with the course of HCM and myocardial strain evaluation can be applied in the evaluation of left ventricular function in hypertrophy cardiomyopathy.