Normal Reference Values for Assessing Diastolic Function Using the Parameterized Diastolic Filling Formalism Method in Patients with Normal Results of Rest and Stress Echocardiography

The parameterized diastolic filling (PDF) method can be used to study the mechanics of early diastolic left ventricular (LV) filling. However, there are no publications describing the reference ranges of the PDF parameters. This study retrospectively recruited patients with normal results on rest and stress echocardiography and no diabetes or hypertension (n=138, 45% female). DICOM images of the resting E-wave from transmitral pulsed wave Doppler flow velocities were analyzed using freely available software. Viscoelastic energy loss (c) and stiffness (k) were higher in males compared to females (p≤0.001 for both). There were no correlations between any of the PDF parameters and age (p>0.05 for all). In males, stiffness was correlated with systolic blood pressure (r=0.24, p=0.04), and load and filling energy were correlated with diastolic blood pressure (r=-0.27, p=0.02, and r=-0.29, p=0.01, respectively). Sex-specific normal 95% reference limits for PDF analysis of early LV filling are presented for clinical use.