Methods for Assessing Left Ventricular Diastolic Distensibility

The major property of the myocardium that determines leftventricular (LV) filling is its distensibility. The simplest measurefor its assessment is the LV end-diastolic pressure–volume ratio,although it can vary within a wide range and is highly dependenton inflow and resistance boundary conditions, making distensibilitydifficult to assess. Here, we consider six calculated indices ofLV diastolic stiffness, most of which are based on Hooke’s law,comparing their stability, variation, and correlation coefficientswith different hemodynamic parameters. The diastolic stiffness indexNo. 4 proved to be the only measure that takes into account an increasein LV stiffness over diastole. It shows a weak dependence on LV ejectionfraction, heart rate, and other parameters of LV hemodynamics, andhence can be used to assess LV diastolic distensibility in variouscardiac pathologies.