The degree of diastolic dysfunction may explain the difference in clinical symptoms between patients with similar degrees of systolic dysfunction. Pseudonormal mitral filling pattern with increased left ventricular filling pressure is a transitional stage of diastolic dysfunction and is difficult to distinguish from normal. Preload is one of factors affecting the diastolic filling patterns and mitral flow patterns may be influenced by changes in preload in the absence of changes in the left ventricular pressure-volume curve. The changes in the mitral flow velocities caused by preload reduction may be useful in distinguishing patients with a pseudonormal pattern from those with normal. The aim of this study was to establish whether the effect of changes in pulmonary venous flow pattern by preload reduction may be useful in distinguishing pseudonormal pattern from normal.

This study included 40 patients (men 25, female 15, average age 51.0±11.2 years) underwent left side cardiac catheterization among patients with normal or pseudonormal patterns. All patients with pseudonormal group had increased LVEDPr (>15 mmHg). The Doppler mitral inflow & pulmonary venous flow parameters at baseline and during reduction of preload using Valsalva maneuver were recorded.

1) There were no difference in sex, diabetes mellitus, hypertension and lipid profiles between both groups. The left ventricular systolic function was better and mean age was younger in normal than pseudonormal group (p<0.05). The incidence of coronary artery disease was more frequent and LV mass was more increased in pseudonormal than normal group (p<0.05). 2) E and A velocities were significantly decreased but E/A ratio was still >1.0 during Valsalva maneuver in normal group (p<0.05). In pseudonormal group, E velocity was significantly decreased but A velocity was not significantly changed and the E/A ratio was <1.0 during Valsalva (p<0.05). Therefore the change revealed masked LV relaxation abnormality pattern. 3) S and D velocities of pulmonary venous flow were significantly decreased and S/D ratio was significantly increased in both groups (p<0.05). The % changes before and after Valsalva maneuver showed that S velocity was less decreased, D velocity was more decreased and S/D ratio was more significantly increased in pseudonormal than normal group (p<0.05). That revealed masked LV relaxation abnormality pattern.

The Valsalva maneuver for preload reduction is a relatively simple, easily applicable, safe and reproducible method of acutely reducing venous return. The assessment of changes in pulmonary venous flow pattern by preload reduction may be helpful in distinguishing pseudonormal and normal diastolic function in addition to changes in mitral inflow pattern.