In order to investigate the effects of increasing degrees of left ventricular filling impairment on left atrial function, in 9 A-fillers (E/A ratio less than 1, E wave deceleration time greater than 170 ms) and 9 E-fillers (E/A ratio greater than 1, E wave deceleration time less than 150 ms) we constructed the left ventricular and the left atrial volume curves according to a previously validated Doppler 2-dimensional echo method which combines mitral and pulmonary venous flow. Eight normals served as control. The left atrial reservoir (defined as maximum-minimum atrial volume), pump (defined by the volume of blood that enters the left ventricle with the atrial contraction) and conduit functions (defined as left ventricular filling volume--the reservoir and the pump volume) expressed as % of the left ventricular filling volumes, varied significantly between normals (37 +/- 9%, 25 +/- 3%, 37 +/- 11%), A-fillers (48 +/- 9% p less than 0.05, 39 +/- 5% p less than 0.05, 14 +/- 10% p less than 0.001) and E-fillers (27 +/- 6% p less than 0.05, 19 +/- 7% p less than 0.05, 54 +/- 10% p less than 0.01). Also maximum left ventricular and left atrial volumes differed significantly (normals 165 +/- 31 ml, 76 +/- 20 ml; A-fillers 174 +/- 33 ml, 100 +/- 20 ml p less than 0.05; E-fillers 322 +/- 34 ml p less than 0.001, 136 +/- 41 ml p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)