Layer-specific longitudinal strain predicts left ventricular maximum wall thickness in patients with hypertrophic cardiomyopathy.

Abstract

The aim of this study was (a) to clarify the detailed mechanisms of structural and functional abnormalities of myocardial tissue in hypertrophic cardiomyopathy (HCM) using layer-specific strain (LSS) and compare it with healthy subjects (b) to investigate the diagnostic accuracy of LSS for HCM. Forty-one patients with HCM and preserved left ventricular ejection fraction (LVEF; 66% male, 52±18years, LVEF 62.9%±3.7%) and 41 controls matched for age and sex (66% male, 52±20years, LVEF 63.5%±8.2%) underwent 2D-speckle tracking echocardiography. Absolute values of LSS were globally lower and the ratio of endocardial/epicardial layer (End/Epi ratio) was higher in HCM. LSS gradually increased from the epicardial toward the endocardial layer at all chamber views and at all levels of the LV. LSS and End/Epi ratio at the apex were higher than those at the middle or basal level of the LV. End/Epi ratio was correlated with LV maximal wall thickness both controls (r=.35, P=.03) and HCM (r=.81, P<.001). End/Epi ratio was an independent factor associated with LV maximal wall thickness (β=0.96, P<.001). A higher End/Epi ratio (≥1.31) was associated with diagnostic criteria for HCM (sensitivity 98%, specificity 95%, area under the curve 0.99, P<.001). LSS has the potential for unraveling the mechanism of impaired LV wall motion in HCM and to accurately detect HCM.