Diastolic Dysfunction Persists After Unloading by Left Ventricular Assist Device (LVAD) Support

Left Atrium (LA) size has prognostic importance in a variety of cardiac conditions [1] and is known to be enlarged with decreased contractile function in patients with congestive heart failure (CHF) [2]. Nearly 5 million Americans have CHF [3] and a majority of these patients display diastolic dysfunction, which is an abnormality in the left ventricle (LV) myocardial relaxation and/or compliance that alters the ease with which the blood is accepted into the LV from the LA during diastole [4]. Due to abnormal LV filling, the LA experiences intense stress and elevated pressures. In fact, the left atrium is exposed directly to the LV diastolic pressure through the open mitral valve (MV) and because of its thin wall structure it tends to dilate with increasing pressure [5]. This augmented LA size and increased contractility and booster function are some of the mechanisms compensating for decreased early filling in patients with reduced LV compliance [6]. Over time, the LA compensatory contribution decreases, this may lead to intrinsic left atrium dysfunction [7]. This in turn results in a progressive decline in health unless the hearts’ inadequate blood flow is augmented by a left ventricular assist device (LVAD). Although LVAD implantation rest the heart, restores function to the ventricle [8], and improve overall function [9], its effects on the left atrium remain unclear. The purpose of the present study was to use 2D and Doppler echocardiography to define the parameters for assessing LVAD unloading and determine its effect on LA diameter, area, volume, and pressure in patients prior to and following LVAD implantation.