P4348Early assessment of left ventricular function by layer-specific strain and its relationship to pulsatile arterial load in patients with coronary slow flow

Abstract Background Previous studies reported controversial Left ventricular (LV) function impairment and pathophysiology in patients with coronary slow flow (CSF). Greater arterial load has been shown to increase aortic impedance and endothelial shear stress, potentially affecting coronary anatomy and function. We investigated LV systolic function by a new layer-specific strain technology and assessed the association between pulsatile arterial load and contractility. Methods and results A total of 70 patients with CSF and 50 controls with normal coronary angiography were included in the study. Layer-specific longitudinal and circumferential strains were assessed from endocardium, mid-myocardium and epicardium (GLS-endo, GLS-mid, GLS-epi and GCS-endo, GCS-mid, GCS-epi) by two-dimensional speckle tracking imaging (2D-STI). Pulsatile arterial load was estimated by indexed arterial compliance (ACI). Layer-specific GLS showed a decreasing gradient from the endocardium to the epicardium in both controls and CSF group. GLS-endo and GLS-mid in CSF group were significantly lower than the control group (all P<0.05). Layer-specific longitudinal strain showed a good correlation with the number of affected coronary arteries (all P<0.05) and the mean thrombolysis in myocardial infarction frame count (TFC) (all P<0.05). ACI was lower in CSF patients (P=0.005) and ACI was correlated negatively with layer-specific GLS (all P<0.05). Conclusion Layer-specific evaluation of the LV provides an understanding of the layer-specific properties of the LV wall and the possible process of the LV impairment in patients with CSF. Greater pulsatile arterial load, as manifested by a lower ACI, is coupled with worse LV longitudinal function in CSF patients.