Myocardial work evaluation
WASTED
Myocardial work was calculated as a combination of LV strain and the estimated LV pressure curve. In the software, the LV strain provided the P–S loop, which was calculated using 2D speckle tracking echocardiography, and peripheral systolic blood pressure was measured non-invasively under the assumption that the peak LV pressure was equal to the peak systolic arterial pressure. The isovolumic and ejection phases were determined through the opening and closing times of the mitral and aortic valvesGlobal work index (GWI): total work of LV, that is, the area under the curve of the P–S loop.Global constructive work (GCW): work of LV that contributes to LV ejection during systole, that is, myocardial shortening during systole (positive segmental work) and lengthening during isovolumic relaxation (negative segmental work).Global wasted work (GWW): work of LV that does not contribute to LV ejection, specifically, myocardial lengthening during systole (negative segmental work) and shortening during isovolumic relaxation (positive segmental work).Global work efficiency (GWE): the ratio of constructive work to total work (GCW/[GCW + GWW]).The BP of all patients was measured in the supine position after a 5-min rest just before echocardiography. Supplementary Fig. 