Layer‐specific strain echocardiography may reflect regional myocardial impairment in patients with hypertrophic cardiomyopathy

Figures

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  Fig. 1. Representative images of two-dimensional (2-D) left ventricular (LV) global layer-specific strain (LSS) analysis in a patient with hypertrophic cardiomyopathy (HCM) from apical 4-chamber views. The 2-D LV global LSS was also measured from apical 2- and 3-chamber views. The analyses were performed using Echo PAC version 201. The quantitative strain measurements of the endocardial (a), middle (b) and epicardial myocardial layers (c) were automatically calculated after the region of interest was manually traced and adjusted

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  Fig. 2. Representative bull’s-eye map of a patient with hypertrophic cardiomyopathy. A multilayer bull’s-eye map, showing the epicardial (a), middle (b), and endocardial myocardial layers (c), was automatically generated after the layer-specific strain was measured in 3 apical views (apical 4-, 2-, and 3-chamber views). An 18-segment model was used in the segmental analysis

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  Fig. 3. In healthy volunteers, negative transmural gradient of longitudinal strain (TGLS) was observed in almost all segments. The normal range of TGLS greatly varied among the segments. However, the TGLS was relatively consistent within the basal, middle, and apical levels. A significant TGLS from the base toward the apex was observed. bas: basal; ap: apical; Post: posterior; AntSept: anteroseptal; Sept: septal; Lat: lateral; Inf: inferior; Ant: anterior

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  Fig. 4. The transmural gradient of longitudinal strain (TGLS) in the non-hypertrophic segments of patients with hypertrophic cardiomyopathy (HCM) was not significantly different from that of healthy controls according to level. However, the TGLS in the hypertrophic segments was significantly higher than that in the non-hypertrophic segments at almost all levels

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  Fig. 5. Abnormal transmural gradient of longitudinal strain (TGLS) was significantly associated with chest pain (AUC = 0.805, p = 0.002), and a large area of TGLS (> 4 segments) had moderate accuracy for predicting chest pain (sensitivity, 73.3 %; specificity, 70.0 %) in the ROC curve analysis, while hs-cTnT (AUC = 0.479, p = 0.843) and LVOT gradient (AUC = 0.564, p = 0.528) did not significantly predict chest pain in HCM patients (a). Abnormal TGLS was not associated with heart failure (b). ROC: receiver operating characteristic; AUC: area under the curve. hs-cTnT: high-sensitive cardiac troponin T; LVOT: left ventricular outflow tract

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  Fig. 6. Bland-Altman plots of the intra-observer and inter-observer reproducibility of the transmural gradient of longitudinal strain (TGLS). The limit of agreement was − 1.532–1.449 % for the intra-observer comparison (a), and − 2.929–2.629 % for the inter-observer comparison (b)

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  Fig. 7. Scatter plot of TGLS (a) and the ratio of endocardial strain and epicardial strain (b). Note that there’s an abnormal extreme value in the ratio of endocardial strain and epicardial strain because the epicardial strain was near to zero (-0.02 %)