Diastolic Function Grading (ASE/EACVI 2016)

The Four Screening Variables

The 2016 ASE/EACVI guideline (Nagueh et al.) streamlined diastolic function assessment in patients with normal LV ejection fraction and no myocardial disease into four measurable variables, each with a fixed abnormal cutoff:

Note that the average E/e′ ratio combines septal and lateral e′ measurements; this average — not either value alone — is compared to the 14 cutoff. Each of the five rows functions as one of the four screening criteria (e′ contributes as a single criterion via its septal/lateral cutoffs, alongside average E/e′, LAVi, and TR velocity).

Step 1: Is Diastolic Function Normal or Abnormal?

In a patient with normal LVEF, count how many of the four criteria (e′, average E/e′, LAVi, TR velocity) are abnormal:

• 0 or 1 abnormal → diastolic function is normal
• Exactly 2 of 4 abnormal (50%) → study is indeterminate
• More than 50% abnormal (3 or 4 of 4) → diastolic dysfunction is present, and the exam proceeds to grading

This binary screening step deliberately limits the variables considered to reduce the ambiguity of the older, more complex 2009 algorithm, making the four-variable rule the most heavily tested piece of this topic.

Step 2: Grading Diastolic Dysfunction (Grades I–III)

Once diastolic dysfunction is established (or in patients with reduced EF or known myocardial disease, where grading is applied directly), the mitral inflow E/A ratio and E velocity become the primary grading tool, supported by the same three ancillary criteria (average E/e′ >14, LAVi >34 mL/m², TR velocity >2.8 m/s) used above.

A few working rules simplify this table for exam purposes:

• An E/A ratio ≥ 2 is restrictive physiology (Grade III) regardless of the supportive criteria — this is the single most memorable cutoff in diastolic grading.
• An E/A ratio ≤ 0.8 with a low E velocity (≤50 cm/s) is classic Grade I impaired relaxation with normal filling pressure.
• An E/A ratio in the 0.8–2 "gray zone" (or a low E/A with an elevated E velocity) requires the three supportive criteria (average E/e′, LAVi, TR velocity) to distinguish normal aging patterns from Grade II pseudonormal filling — if at least two of the three supportive criteria are positive, filling pressure is considered elevated and the pattern is graded Grade II.

Why These Variables Were Chosen

Each variable captures a different physiologic signal. e′ (early diastolic tissue Doppler velocity at the septal or lateral mitral annulus) reflects myocardial relaxation and falls with age and with intrinsic diastolic dysfunction, largely independent of preload. E/e′ combines the transmitral E velocity (preload- and relaxation-dependent) with e′ (relaxation-dependent) to estimate LV filling pressure — a high E relative to a low e′ suggests the high E velocity is being driven by elevated LA pressure rather than normal relaxation. LAVi integrates the chronic hemodynamic burden on the atrium over time, making it a marker of chronicity rather than an instantaneous pressure measurement. TR velocity, via the simplified Bernoulli equation, estimates RV systolic pressure, which typically rises when LA pressure is chronically elevated and transmitted backward through the pulmonary circulation.

Supporting Doppler Signs

Beyond the four core screening variables, several additional Doppler findings reinforce a grade once assigned rather than replace the primary criteria. E-wave deceleration time (DT) shortens as filling pressure rises and LA-to-LV pressure equalizes more rapidly; a markedly shortened DT accompanies restrictive (Grade III) physiology, while a prolonged DT is typical of impaired relaxation (Grade I). Pulmonary vein flow — specifically a reduced systolic-to-diastolic (S/D) filling fraction and a prolonged pulmonary vein atrial-reversal (Ar) duration compared with mitral A-wave duration — supports elevated LA pressure in equivocal cases. The Valsalva maneuver can help unmask pseudonormal (Grade II) filling by transiently reducing preload: a true pseudonormal pattern reverts toward a Grade I (impaired relaxation) pattern during the strain phase, while normal diastolic function does not meaningfully change.

Exam Application

AE exam items in this area commonly present a table or vignette of raw values — septal and lateral e′, mitral E and A velocities, LAVi, and TR velocity — and ask the candidate to either (1) determine whether diastolic function is normal, indeterminate, or abnormal using the four-variable screen, or (2) assign a specific grade (I, II, or III) using the E/A ratio and supportive criteria. The most common wrong answers involve applying the average E/e′ cutoff of >14 to a single (not averaged) e′ value, or forgetting that E/A ≥2 overrides the need to check supportive criteria for Grade III. Because this algorithm assumes normal EF and no significant valve disease, remember that a different, disease-specific approach is required in patients with reduced EF, mitral stenosis, mitral annular calcification, prosthetic mitral valves, or atrial fibrillation, where several of the standard cutoffs are not validated.