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

Aims: 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.

Methods And Results: Forty-one patients with HCM and preserved left ventricular ejection fraction (LVEF; 66% male, 52 ± 18 years, LVEF 62.9% ± 3.7%) and 41 controls matched for age and sex (66% male, 52 ± 20 years, 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).

Conclusion: LSS has the potential for unraveling the mechanism of impaired LV wall motion in HCM and to accurately detect HCM.