Attenuation of 3-Dimensional Epicardial Strain from Cardiac Magnetic Resonance Associated with Obstructive Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a genetic disease that leads to left ventricle (LV) hypertrophy with or without the presence of LV outflow tract obstruction. The aim of this study was to assess endocardial and epicardial strains based on cardiac magnetic resonance (CMR) images for control subjects and patients with and without obstruction. CMR scans were performed for 19 control subjects and 19 HCM patients. Endocardial and epicardial contours were delineated in cine two-, three-, and four-chamber MR images by CMRtools. Endocardial (resp. epicardial) length at end-diastole \(L_\mathrm{{ED,endo}}\) (resp. \(L_\mathrm{{ED,epi}}\)) and end-systole \(L_\mathrm{{ES,endo}}\) (resp. \(L_\mathrm{{ES,epi}}\)) were calculated and endocardial and epicardial strains were defined as S\(_\mathrm{{endo}}=|\ln (L_\mathrm{{ES,endo}}/L_\mathrm{{ED,endo}})|\times 100\%\) and S\(_\mathrm{{epi}}=|\ln (L_\mathrm{{ES,epi}}/L_\mathrm{{ED,epi}})|\times 100\%\), respectively. S\(_\mathrm{{endo}}\) and S\(_\mathrm{{endo}}\) were significantly different between control and HCM patients (both \(P 17.2\%\) had the best sensitivity 94.7\(\%\) and 94.7\(\%\) accuracy to differentiate HCM from normal subjects (AUC = 0.972), and 3-dimensional average endocardial strain \(> 18.8\%\) had the best sensitivity 76.9\(\%\) and 100\(\%\) accuracy to differentiate HCM with and without obstruction (AUC = 0.859). Therefore, 3-dimensional endocardial and epicardial strains may be useful in triage and management of HCM patients with and without obstruction.