Schematic representation of the variations in Doppler filling patterns in relation to the left atrial pressures. The thick vertical lines represent the A waves and the thin lines represent the E waves. The main patterns from -1 to 3 are shown. Note that these are not absolute velocities but represent relative heights of the waves. The relative behavior of A and E waves with relation to left atrial pressures is extrapolated by the connecting thick and thin lines. This is a continuous variable and we can determine the pressure by determining the pattern at the appropriate point on the horizontal axis. A shift to the right indicates increasing pressure and a shift to the left indicates decreasing pressure. It is also possible to accurately label a particular pattern. For example E = A could be pattern -0.5, 0.5 or 1.5 and if E is lesser than A, the pattern could be -0.75, 0.75 or 1.25. The exact pattern could then be determined by the clinical circumstance and/or using a physiological maneuver and/or drug challenge. These hierarchal changes are best demonstrated in the young especially with systolic dysfunction.