Abstract
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.