The Mitral inflow pattern shows the filling of the atrium and the ventricles, it shows the difference in the pressure between the two. Understanding the mitral inflow pattern has a great deal of importance in diastolic dysfunction grading. Mitral inflow has two patterns namely the early rapid filling (E) and the late filling with atrial contraction (A). These patterns help determine the diastolic dysfunction of the heart since it affects the early filing and late filing. In a normal diastolic function, the blood fills at regular pressure, and the E-wave is taller than the A-wave (as shown below in Figure 1) with a cut-off value of ≤ 0.8 & > 2.
Supernormal mitral inflow filling
This is noticed in the younger individuals who are physically active, the blood flows out from the atrium, there is no much volume left during the atrium contraction and hence the A-wave is much smaller than the E-wave, the ratio is >2. The E-wave is twice as big as the A-wave (as shown in the below figure 2)
Impaired relaxation (grade I)
This is the most common kind among adults above the age of 60 years. Because of the stiffness in the ventricle, it takes longer than usual for the early filling to take place resulting in E-wave being shorter than A-wave (as shown in figure 3). The blood transported is less in amount, hence there is more blood present during atrial contraction and the deceleration time increases. A-wave is seen bigger than normal, and the E/A ratio will be ≤ 0.8.
Pseudonormal (Grade II)
In Pseudonormal the left atrium and left ventricle pressure increase causing the ventricle to fill early during the diastole. This spectrum pattern resembles that of normal mitral inflow filling, where the E-wave relatively increases compared to A-wave (as shown in figure 4). The E/A ratio will be normal, 0.8 +- 1.5. and the deceleration time will be 160-200 ms. The main way to differentiate between Pseudonormal and normal patterns is through Valsalva, the E/A ratio is < 1 with Valsalva.
Reversible restrictive (Grade III)
When the filling pressure increases between the left atrium and the left ventricle during early diastole the slope increases. The E/A ratio is ≥ 2 or even reaches the value of 5 or more, the deceleration time becomes < 160 ms, and the e/e ratio gets elevated. The spectrum appears as E-wave longer than A-wave and A-wave even shorter (as shown in figure 5). Doctors in certain cases will apply the Valsalva maneuver to reduce the pressure on the left atrial and reverse restrictive filling to Pseudonormal
Fixed restrictive (Grade IV)
This is the most severe kind of dysfunction where the left atrial pressure is elevated, the E/A ratio is > 2.0, and the e/e ratio is elevated as well. The deceleration time is low too and the only way to distinguish Grade IV from grade III is the Valsalva maneuver, the atrial pressures cannot be reserved as in grade III. This pattern is present only in severe heart conditions. The E-wave appears longer than A-wave and A-wave shorter than normal.
To summarize the above, 5 patterns are ranging from normal to severe dysfunction and they all have different E/A ratios and deceleration time. Medical professionals use Doppler and tissue doppler assessment to detect any of the patterns/spectrums or diastole dysfunctions overall. The only issue is that Doppler ultrasound shows the mitral inflow pattern however does not help with grading the dysfunctions. Tissue doppler ultrasound along with Doppler helps detect the dysfunctions and take the next steps in the treatment.