This is evaluated in apical 4 chamber view, using PW, with sample volume at the tip of the mitral leaflets.

E/A ratio –

Normal values are between 0.75 and 1.5.  Normal E is 0.6 to 0.9 m/sec and normal A is 0.3 to 0.5 m/sec.

In grade 1 diastolic dysfunction, it decreases. In grade 2 diastolic dysfunction, it normalises. In grades 3 and 4 diastolic dysfunction, it increases.

In the young, E/A ratio can exceed 2.0. This may be mistaken for a restrictive pattern.
E/A ratio decreases with tachycardia. Also, with tachycardia E and A waves fuse and so it is difficult to measure the E/A ratio.
E/A ratio can be measured only if the patient is in sinus rhythm.

E deceleration time- 

For measuring EDT, the mid portion of the E deceleration is to be used. Normal EDT is 150 to 220 msec. In diastolic dysfunction, first EDT increases (grade 1) and then returns to normal (grade 2) and then decreases (grades 3 and 4).

IVRT –

This is measured from apical 5 chamber view by getting both aortic and mitral velocities in a single view. Normal upper limits are 90, 100 and 105 in age <30, 30-50 & >50 respectively. In diastolic dysfunction, it first increases, but then decreass to normal as high left atrial pressure causes earlier mitral valve opening.

Grades of diastolic dysfunction-

Diastolic dysfunction has four grades.

In grade 1 diastolic dysfunction, also called delayed relaxation pattern, E/A ratio decreases to below normal and EDT (&IVRT) increases.

In grade 2 diastolic dysfunction, also called pseudonormalisation, E/A ratio increases to the normal range and EDT decreases to the normal range. The presence of diastolic dysfunction can be unveiled by doing Valsalva maneuver, when the pattern transiently reverts to grade 1 (due to decrease in preload).

Grades 3 and 4 are together called restrictive pattern. Here, E/A ratio increases to above normal range and progressively increases with worsening of diastolic dysfunction. The EDT (&IVRT) decreases to below normal range. Grade 3 reverses to grade 1 pattern with Valsalva while grade 4 does not. So, grade 3 is called reversible restrictive pattern and grade 4 is called irreversible restrictive pattern.