Myocardial Work Analysis During IVR

The MW parameters for ventricular systole were derived by entering the timings of the mitral valve closure and aortic valve closure (defined from the Doppler trace at the aortic valve). Global systolic constructive work (GSCW) was defined as the MW during shortening in systole, and global systolic wasted work (GSWW) was defined as the MW during lengthening in systole. The MW parameters specific for IVR were calculated through deduction: MCW_IVR (myocardial constructive work during IVR, the myocardial work performed for lengthening during IVR) = GCW—GSCW; MWW_IVR (myocardial wasted work during IVR, the myocardial work performed for shortening during IVR) = GWW—GSWW. The total myocardial work during IVR (MW_IVR) was obtained from the sum of MCW_IVR and MWW_IVR. Myocardial work efficiency during IVR (MWE_IVR) was calculated, as follows: MCW_IVR / (MCW_IVR + MWW_IVR) × 100%. The MW_IVR parameters were normalized by dividing these by the corresponding IVRT.