['Although an intraventricular filling delay has been observed in patients with a psuedonormalized transmitral flow pattern, little is known about the underlying hydrodynamic nature of this phenomenon.', 'To examine those hydrodynamics, we studied every echocardiographic frame showing ventricular inflow (80 Hz) in the apical long-axis view and M-mode image using contrast echocardiography in 29 patients with a psuedonormalized pattern and in 26 normal controls. The velocity of the filling flow front (Vp), the ratio of Vp to E, and the mean radius of the vortices associated with the filling flow were measured.', 'In both groups, vortices were observed at the ridge of the mitral valve during acceleration of the E-wave. The mean radius of the vortices was greater in the pseudonormalized filling group than that in the control group (8 +/- 2 vs 3 +/- 1 mm, P < 0.0001). Vp was smaller in the pseudonormalized group than in the control group (36 +/- 6 vs 47 +/- 6 cm/sec, P = 0.0008). Vp/E was < 1 and smaller in the pseudonormalized group than that in the control group (0.46 +/- 0.13 vs 0.59 +/- 0.07, P = 0.014) and negatively correlated with the mean radius of the vortices (r = 0.54, P < 0.0001).'] Is the wake of a large vortex associated with intraventricular filling delay in impaired left ventricles with a pseudonormalized transmitral flow pattern?