Influence of acute preload changes on mitral annulus velocity measured by tissue Doppler echocardiography in critically ill patients.

Aim: The assessment of diastolic function remains difficult in critical care patients because of unstable preload conditions. Described as fairly insensitive to preload changes, tissue Doppler velocity measurement at the lateral mitral annulus (e' (lat) ) may help evaluate diastolic function. Our aim was to prospectively evaluate e' (lat) changes in relation to fluid expansion in critically ill patients.

Methods: This prospective observational study was conducted in critically ill, mechanically ventilated, patients in sinus rhythm without previously known cardiac disease. Echocardiography was performed before and 1 hour after a fluid challenge (infusion of Gelofusine 500 ml in 30 minutes). Conventional pulsed wave Doppler indices of left ventricular diastolic function and tissue Doppler velocity lateral (e' (lat) ) and septal (e' (sept) ) mitral annulus velocity were measured, whereas hemodynamic data were simultaneously collected.

Results: Twenty patients (age, 55 ± 15 years; Simplified Acute Physiology Score II, 45 ± 10) were enrolled. Systolic function was preserved in all patients. Cardiac index increased (p < 0.05), as did early diastolic mitral velocity (E wave) (p = 0.001), and e' (lat) and e' (sept) (p = 0.02) after fluid challenge.

Conclusions: This study confirms the preload dependence and limited clinical usefulness of most Doppler variables, such as e' (lat) , to evaluate diastolic function in intensive care unit patients. Indices, such as E/e', may be of interest in these cases.