Tachycardia during atrial fibrillation (AF) is known to worsen pulmonary congestion in patients with impaired left ventricular (LV) function. However, the pulmonary venous flow (PVF) dynamics in patients with AF and LV systolic impairment is still not well known. In order to determine the fashion in which heart rate and LV systolic function influence PVF dynamics in patients with AF, we studied 24 patients with AF including 12 patients with normal LV systolic function (Lone-AF