Noninvasive assessment of myocardial work during left ventricular isovolumic relaxation in patients with diastolic dysfunction

Background This study aims to investigate the value of myocardial work (MW) parameters during the isovolumic relaxation (IVR) period in patients with left ventricular diastolic dysfunction (LVDD). Methods This study prospectively recruited 448 patients with risks for LVDD and 95 healthy subjects. An additional 42 patients with invasive measurements of left ventricular (LV) diastolic function were prospectively included. The MW parameters during IVR were noninvasively measured using EchoPAC. Results The total myocardial work during IVR (MW IVR ), myocardial constructive work during IVR (MCW IVR ), myocardial wasted work during IVR (MWW IVR ), and myocardial work efficiency during IVR (MWE IVR ) of these patients were 122.5 ± 60.1 mmHg%, 85.7 ± 47.8 mmHg%, 36.7 ± 30.6 mmHg%, and 69.4 ± 17.8%, respectively. The MW during IVR was significantly different between patients and healthy subjects. For patients, MWE IVR and MCW IVR were significantly correlated with the LV E/e’ ratio and left atrial volume index, MWE IVR exhibited a significant correlation with the maximal rate of decrease in LV pressure (dp/dt per min) and tau, and the MWE IVR corrected by IVRT also exhibited a significant correlation with tau. Conclusions MW during IVR significantly changes in patients with risks for LVDD, and is correlated to LV conventional diastolic indices, including dp/dt min and tau. Noninvasive MW during IVR may be a promising tool to evaluate the LV diastolic function.