[Doppler echocardiography for the assessment of left ventricular diastolic function: methodology, clinical and prognostic value].

Overview

abstract

To date, left ventricular diastolic function can be clinically assessed by Doppler echocardiography. The Doppler recording of mitral inflow and pulmonary venous flow provides main information about ventricular diastolic properties. At the level of the mitral inflow we can measure the early diastolic peak velocity (E), atrial peak velocity and derive their ratio, the E velocity deceleration time and isovolumic relaxation time, and calculate atrial filling fraction. At the level of the pulmonary veins, the peak systolic velocity (S), the peak diastolic velocity (D), the S/D ratio, the peak of reverse atrial velocity and its duration, above all in terms of difference with the mitral A duration, characterize the different patterns of diastolic function. Also the new ultrasound technologies are clinically useful to define ventricular diastolic properties. The myocardial early diastolic velocity (Em) detectable by pulsed tissue Doppler at the level of the mitral annulus, and the flow propagation velocity (Vp) recordable by color M-mode of left ventricular inflow, both relatively preload-independent, are measurements related to tau, the reference hemodynamic variable. The E/Em and E/Vp ratios provide accurate estimation of the changes in left ventricular end-diastolic pressure. They allow us to distinguish the pseudonormal and restrictive patterns from the normal pattern and are, therefore, alternative tools to Valsalva maneuver of mitral inflow and pulmonary venous flow. The predictive value of the pattern of abnormal relaxation (grade I of diastolic dysfunction) and both the reversible and irreversible restrictive patterns (grade III and IV respectively) is now demonstrated and permits important prognostic stratification and appropriate therapeutic management.