LV Diastolic Function Grading: 2025 ASE Algorithm
Thresholds, algorithms and interpretation from the 2025 ASE update — diagnosis of diastolic dysfunction, left atrial pressure estimation, dedicated pathways for AF, MAC, pulmonary hypertension and transplant recipients, measurement pitfalls and reporting.
The interactive tool below applies the correct 2025 ASE pathway once you select the clinical context. The full reference — diagnostic criteria, threshold tables, phenotype algorithms, pitfalls and reporting guidance — follows underneath.
Interactive Diastolic Function Grading Tool
Select the clinical context and enter measurements step by step. The tool applies the correct 2025 ASE algorithm and shows the variables that drove the result. Use the Back button to revise any step.
Result
Two Separate Questions: Is Diastolic Dysfunction Present, and Is LAP Elevated?
The 2025 ASE update separates two questions that are frequently conflated. The first — is LV diastolic dysfunction present? — follows Figure 2. The second — is mean left atrial pressure elevated, and what grade? — follows Figure 3. Both use the same core e′ thresholds: septal e′ ≤ 6 cm/s, lateral e′ ≤ 7 cm/s, or average e′ ≤ 6.5 cm/s, which indicate abnormal relaxation irrespective of age. Age-specific values may additionally be considered when judging whether e′ is abnormally reduced, particularly in younger patients whose normal e′ runs well above the fixed thresholds.
Step 1 — Assess LV Relaxation
The core thresholds are fixed: septal e′ ≤ 6, lateral e′ ≤ 7, or average e′ ≤ 6.5 cm/s. The guideline additionally provides age-specific values that may be considered when determining whether e′ is abnormally reduced — most useful in younger patients, where an e′ that clears the fixed threshold can still be well below the expected range for age.
| Age (optional refinement) | Abnormal septal e′ | Abnormal lateral e′ | Abnormal average e′ |
|---|---|---|---|
| 20 – 39 years | < 7 cm/s | < 10 cm/s | < 9 cm/s |
| 40 – 65 years | < 6 cm/s | < 8 cm/s | < 7 cm/s |
| > 65 years | < 6 cm/s | < 7 cm/s | < 6.5 cm/s |
Step 2 — Markers of Elevated LAP and Structural Remodelling
| Parameter | Abnormal | Role |
|---|---|---|
| Average E/e′ | > 14 | Elevated LAP marker |
| LA reservoir strain (LARS) | ≤ 18% | Elevated LAP marker |
| E/A ratio (high) | ≥ 2 | Elevated LAP marker |
| E/A ratio (low) | ≤ 0.8 | Impaired relaxation — not elevated LAP |
| LA volume index (biplane) | > 34 mL/m² | Structural surrogate |
| LV mass index — men | > 115 g/m² | Structural surrogate |
| LV mass index — women | > 95 g/m² | Structural surrogate |
LA Reservoir Strain: A Major Addition in the 2025 ASE Guideline
The left atrium is a dynamic chamber with three mechanical phases. During ventricular systole the mitral valve is closed and the atrium expands as it receives pulmonary venous return — the reservoir phase. On mitral valve opening blood passes through the atrium into the ventricle — the conduit phase. Atrial contraction then delivers the final increment of filling — the contractile phase.
LA reservoir strain (LARS) measures atrial expansion during the reservoir phase. It is the phase used because the atrium is then a closed chamber directly exposed to the pressure required to fill the ventricle. LARS therefore integrates LV longitudinal shortening, LA compliance and LA myocardial disease into a single number. It is not interchangeable with LAVi: LA volume is a structural marker of cumulative exposure, which may remain normal in early disease and may be enlarged for unrelated reasons — athletic remodelling, anaemia, atrial arrhythmia, mitral valve disease — whereas LARS is a functional marker that falls before the atrium dilates. That earlier signal is the reason the 2025 update elevated it from a supporting observation to a core marker.
Where LARS Sits in Each Algorithm
| Clinical question | Role of LARS |
|---|---|
| Is diastolic dysfunction present? (Figure 2) | LARS ≤ 18% is a core Step 2 functional marker. With reduced e′, one Step 2 abnormality supports dysfunction; with preserved e′, two are required. |
| Is mean LAP elevated? (Figure 3) | A primary supplementary criterion, used when e′, E/e′ and TR velocity are discordant or incomplete. |
| Atrial fibrillation | Secondary discriminator when exactly two of the four primary variables are abnormal. Never used alone. |
| Pulmonary hypertension | Distinguishes pre-capillary from post-capillary physiology when mitral E/A is intermediate, in preference to lateral E/e′. |
| Significant mitral regurgitation | Not used — LARS has no consistent relationship with LA pressure when MR is significant. |
Two Different Thresholds, Two Different Questions
| LARS | Interpretation |
|---|---|
| ≥ 23% | Within normal limits. Pooled normal reservoir strain in healthy adults is approximately 39%. |
| 19 – 22% | Below the lower limit of normal — abnormal LA mechanics, but does not carry the same specificity for elevated LAP. |
| ≤ 18% | Higher-specificity threshold for elevated LAP used throughout the 2025 diastolic algorithms. |
Measurement Essentials
| Step | Detail |
|---|---|
| Views | LA-focused, non-foreshortened apical four- and two-chamber views. An LV-optimised A4C foreshortens the atrium and inflates the strain value. |
| Frame rate | 40–80 frames/s, typically 50–70. Higher rates are needed only for strain rate, not for reservoir strain. |
| Gating | R-wave (QRS onset) as the zero reference. P-wave gating yields different reservoir values and is not the basis for the reference ranges above. |
| Contour | Trace the whole atrial contour, interpolating across the pulmonary vein orifices and the LA appendage rather than including them. |
| Segmentation | Report global LA strain only. Segmental LA strain is not recommended — the wall is too thin for reliable regional tracking. |
| Software | Dedicated LA analysis software where available. Keep vendor, software version and gating method constant for serial studies. |
Limitations
| Limitation | Consequence |
|---|---|
| Gating method changes the number | The single largest source of variability between published series. State the gating method when the value drives a conclusion. |
| Load dependence | LARS varies with preload and afterload, as do all the conventional diastolic variables. |
| Not pure atrial contractility | Reservoir strain is partly determined by LV longitudinal shortening — it reflects the atrioventricular unit, not the atrium in isolation. |
| Specific but insensitive at ≤ 18% | A normal LARS does not exclude elevated LAP, particularly when LVEF is preserved. |
| Significant primary MR | Disrupts the relationship between LARS and LA pressure entirely. |
| Post-ablation or post-surgical LA | Atrial scarring lowers LARS independently of filling pressure. |
| Atrial fibrillation | Average representative cycles, and never interpret LARS as an isolated marker. |
| Far-field tracking | Poor tracking at the LA roof, pulmonary vein junctions or appendage distorts the global value. Reject the measurement rather than accepting a poor trace. |
Primary Variables — Sinus Rhythm LAP Algorithm
Three primary variables are assessed simultaneously, using the same core e′ thresholds as the diagnostic step. For LA size and strain reference values, see left atrial size and function.
| Variable | Abnormal threshold |
|---|---|
| 1. Reduced e′ velocity | Septal e′ ≤ 6 cm/s, lateral e′ ≤ 7 cm/s, or average e′ ≤ 6.5 cm/s |
| 2. Increased E/e′ ratio | Septal E/e′ ≥ 15, lateral E/e′ ≥ 13, or average E/e′ ≥ 14 |
| 3. Increased TR velocity / PASP | TR velocity ≥ 2.8 m/s or PASP ≥ 35 mmHg |
Supplementary Criteria
| Primary supplementary | Threshold |
|---|---|
| Pulmonary vein S/D ratio | ≤ 0.67 |
| LA reservoir strain (LARS) | ≤ 18% |
| LA volume index (LAVi) | > 34 mL/m² |
| IVRT | ≤ 70 ms |
| Additional supplementary methods | Threshold |
|---|---|
| PR end-diastolic velocity | ≥ 2 m/s |
| PA diastolic pressure | ≥ 16 mmHg |
| Mitral inflow L-wave velocity | ≥ 50 cm/s |
| Ar–A duration | > 30 ms |
| Decrease in mitral E/A with Valsalva | ≥ 50% |
Diastolic Dysfunction Grades
| Grade | Filling pattern | E/A | Mean LAP | Interpretation |
|---|---|---|---|---|
| Normal | Normal relaxation | E > A (young), E ≈ A (older) | Normal | Normal diastolic function with no elevation of filling pressures. |
| Grade 1 | Impaired relaxation | ≤ 0.8 | Normal | Impaired relaxation with normal estimated mean LAP at rest. LVEDP may still be elevated. In symptomatic patients, a normal resting pressure does not exclude exercise-induced elevation — consider diastolic exercise echocardiography. |
| Grade 2 | Pseudonormal | 0.8 – 2.0 | Elevated (mild–moderate) | Inflow appears normal but filling pressures are elevated. Supplementary variables are needed to unmask it. A Valsalva-induced fall in E/A of ≥ 50% distinguishes Grade 2 from Grade 1. |
| Grade 3 | Restrictive | ≥ 2.0 | Elevated (marked) | Markedly elevated filling pressures with a stiff, non-compliant ventricle, short deceleration time and adverse prognosis. |
When Resting Echo Is Not Enough
A normal resting study does not exclude exercise-induced elevation of filling pressure. Diastolic stress echocardiography should be considered in four situations:
| Situation | Why |
|---|---|
| Exertional dyspnoea with Grade 1 dysfunction | Resting LAP is normal by definition in Grade 1, so the resting study cannot address the symptom |
| Indeterminate resting LAP | Exercise frequently resolves the ambiguity |
| High clinical suspicion of HFpEF despite a normal resting study | Filling pressure may only rise with tachycardia and increased venous return |
| Isolated elevation of LVEDP | Predisposes to elevated mean LAP with exercise or tachycardia |
Phenotype-Based Approach — When to Deviate from the Standard Algorithm
The standard diastolic variables break down when the underlying physiology is altered — absent atrial contraction, a rigid annulus, surgically modified chambers, or right ventricular pressure loading. The guideline assigns dedicated algorithms to each phenotype, selecting the variables that remain physiologically valid. The core principle: identify which component of the assessment is unreliable, then shift to the parameter that still works.
| Phenotype | What breaks | Most reliable parameters | Unreliable / avoid |
|---|---|---|---|
| Sinus rhythm | Nothing — normal physiology | e′, E/e′, E/A, LAVi, LA strain | — |
| Atrial fibrillation | No atrial contraction; irregular RR intervals | E velocity and E/e′ averaged over ≥ 5 beats, TR velocity, DT | E/A ratio; single-beat measures; LARS as a standalone marker; PV Ar velocity (absent) |
| Moderate–severe MAC | Rigid annulus lowers e′ while a reduced orifice raises E | E/A, then IVRT when intermediate | e′ and E/e′ — artificially elevated |
| Heart transplant | Denervation, small stiff surgical LA, altered filling physiology | Average E/e′ with strict cut-offs, E/SRIVR, TR velocity | E/A pattern; PV S/D ratio |
| Pulmonary hypertension | RV pressure loading and septal displacement | E/A with E velocity qualifier, then LARS or lateral E/e′ | Septal e′ and average E/e′; TR velocity as a primary variable |
| LBBB / RV pacing | Septal dyssynchrony reduces septal e′ | Lateral E/e′, TR velocity, LA volume and strain | Septal and average E/e′ |
Atrial Fibrillation
Average all measurements over at least five cycles, selecting beats that reflect the average heart rate. No single parameter is sufficient.
| Primary variable | Abnormal |
|---|---|
| Mitral E velocity | ≥ 100 cm/s |
| Septal E/e′ | > 11 |
| TR velocity / PASP | > 2.8 m/s or > 35 mmHg |
| Deceleration time | ≤ 160 ms |
| ≥ 3 abnormal → elevated LAP · ≤ 1 abnormal → normal LAP · 2 abnormal → apply secondary criteria | |
| Secondary criteria (when exactly 2 primary are abnormal) | LARS < 18%, PV S/D < 1, BMI > 30 kg/m² — ≥ 2 present → elevated LAP; none → normal LAP; 1 or unavailable → indeterminate |
Moderate–Severe Mitral Annular Calcification
This pathway applies specifically to moderate or severe MAC, not to mitral valve disease generally. Significant MAC reduces the effective mitral orifice, raising transmitral velocities, while restricting annular excursion and lowering lateral e′ — inflating E/e′ from both directions.
| Finding | Conclusion |
|---|---|
| E/A < 0.8 | Normal LAP |
| E/A > 1.8 | Elevated LAP |
| E/A 0.8 – 1.8, IVRT < 80 ms | Elevated LAP |
| E/A 0.8 – 1.8, IVRT ≥ 80 ms | Normal LAP |
Mitral Stenosis and Mitral Regurgitation
Mitral stenosis and mitral regurgitation have their own indicators and should not be assessed with the MAC pathway.
| Lesion | Indicators of elevated LAP |
|---|---|
| Mitral stenosis | IVRT < 60 ms; mitral A peak velocity > 1.5 m/s; IVRT/TE-e′ < 4.2 |
| Mitral regurgitation | IVRT < 60 ms; Ar–A duration ≥ 30 ms; IVRT/TE-e′ < 5.6 |
Heart Transplant Recipients
| Finding | Conclusion |
|---|---|
| Average E/e′ < 7 | Normal LAP |
| Average E/e′ > 14 | Elevated LAP |
| Average E/e′ 7 – 14, E/SRIVR ≤ 200 cm | Normal LAP |
| Average E/e′ 7 – 14, E/SRIVR > 200 cm | Elevated LAP |
| E/SRIVR unavailable | TR velocity ≤ 2.8 m/s → normal; > 2.8 m/s → elevated |
Pulmonary Hypertension
The aim here is to determine whether the echocardiographic pattern favours pre-capillary or post-capillary physiology. Right heart catheterisation remains definitive when haemodynamic classification is clinically required. Use lateral E/e′ rather than average, because elevated RV pressures displace the septum and make septal e′ unreliable.
| Finding | Favours |
|---|---|
| E/A ≤ 0.8 with E ≤ 50 cm/s | Pre-capillary PH, normal LAP |
| E/A ≥ 2 with reduced e′ | Post-capillary (group 2) PH, elevated LAP |
| E/A 0.8 – 2, or E/A ≤ 0.8 with E > 50 cm/s → LARS > 18% | Normal LAP |
| Same intermediate group → LARS ≤ 18% | Elevated LAP |
| LARS unavailable → lateral E/e′ < 8 / > 13 / 8–13 | Normal / elevated / indeterminate |
Indicators of Elevated LV Filling Pressure in Other Populations
| Population | Key indicators of elevated LV filling pressure |
|---|---|
| Sinus tachycardia | Predominant early filling with depressed EF; IVRT ≤ 70 ms; average E/e′ > 14. When E and A are fused, the compensatory pause after a premature beat may separate the waves. |
| Hypertrophic cardiomyopathy | Average E/e′ > 14; Ar–A ≥ 30 ms; peak TR velocity > 2.8 m/s; LA maximum volume index > 34 mL/m². |
| Restrictive cardiomyopathy | Average E/e′ > 14; DT < 140 ms; E/A > 2.5; IVRT < 50 ms; septal and lateral e′ 3–4 cm/s. These are specific but not sensitive. |
| Mitral stenosis | IVRT < 60 ms; mitral A peak velocity > 1.5 m/s; IVRT/TE-e′ < 4.2. |
| Mitral regurgitation | IVRT < 60 ms; Ar–A ≥ 30 ms; IVRT/TE-e′ < 5.6; average E/e′ > 14 when EF is depressed. |
| LV assist device | E/A > 2; RAP > 10 mmHg; PASP > 40 mmHg; average E/e′ > 14 or septal E/e′ ≥ 15; LAVi > 33 mL/m²; interatrial septum position. |
Measurement Pitfalls
| Measurement | Pitfall | Impact |
|---|---|---|
| Mitral e′ (TDI) | Sample volume not at the annulus | Distorts e′. Place at or within 1 cm of the annular insertion. |
| Mitral e′ (TDI) | Annular calcification distorting tissue motion | e′ unreliable in moderate–severe MAC. Use the MAC pathway. |
| Mitral E velocity | Sample volume not at the leaflet tips | E is maximal at the tips; placement further into the LV underestimates it. |
| Mitral E/A | E–A fusion with tachycardia | E/A uninterpretable when fused. Where E at the onset of A exceeds 20 cm/s, A is artefactually elevated and may mimic impaired relaxation. Use a compensatory pause, or DT and TDI instead. |
| Mitral E velocity | Significant MR increasing transmitral flow | E is raised by volume overload, not LAP alone — E/A and E/e′ may overstate severity. |
| TR velocity | Incomplete envelope or non-parallel alignment | Underestimates PASP. Use multiple windows; an ultrasound-enhancing agent may improve the signal. |
| TR velocity | Elevated TR in non-cardiac PH | Reflects pulmonary pressure, not LAP. Use the PH pathway, which avoids TR as a primary variable. |
| E/e′ ratio | Septal e′ with septal wall motion abnormality, LBBB or RV pacing | Septal e′ unreliable. Use lateral E/e′. |
| LA volume | Foreshortened views or wrong phase | LAVi is measured at end-systole, just before mitral valve opening. Foreshortening underestimates it. |
| All Doppler | Not averaging across cycles | Average ≥ 3 cycles in sinus rhythm and ≥ 5 in atrial fibrillation. |
Constriction versus Restriction
Both present with diastolic heart failure, elevated filling pressures and preserved EF. The distinction matters because constriction is surgically treatable. The 2025 guideline's Figure 7 approach begins with mitral E/A > 0.8 and a dilated IVC, then assesses respirophasic septal motion and medial e′.
| Parameter | Constriction | Restriction |
|---|---|---|
| Respirophasic septal shift / septal bounce | Present — characteristic | Absent |
| Medial annular e′ | > 7 cm/s (annulus paradoxus); > 8 cm/s favours constriction | < 5 cm/s; < 6 cm/s favours restriction |
| Medial versus lateral e′ | Medial ≥ lateral (annulus reversus) | Lateral > medial (normal pattern) |
| Mitral inflow respiratory variation | > 25% (tricuspid > 40%) | Typically minimal |
| Hepatic vein flow | Expiratory diastolic reversal / forward ratio ≥ 0.8 | Systolic or inspiratory reversal |
| Longitudinal strain | Relatively preserved GLS; strain reversus (lateral < septal) | Reduced GLS; apical sparing in amyloidosis |
| Wall thickness | Normal | May be increased — amyloid, Fabry, haemochromatosis |
| Pericardium | May be thickened, but thickness is not required for the diagnosis | Normal; small effusion possible in amyloid |
Reporting Checklist
The guideline recommends that reports state both the diastolic function grade and the filling-pressure conclusion wherever possible. Where a grade cannot be assigned, the filling-pressure status should still be reported.
| Report | Detail |
|---|---|
| Context | Rhythm, heart rate and blood pressure at the time of the study |
| Grade | Normal, Grade 1, Grade 2, Grade 3, or indeterminate |
| Mean LAP | Normal, elevated, or indeterminate — stated separately from the grade |
| Always include | Mitral inflow velocities, mitral annular e′, E/A, average E/e′, peak TR velocity |
| Include if relied upon | PV S/D ratio, mitral A duration, PV Ar duration, IVRT |
| LA reservoir strain | Record where technically feasible — particularly when the primary variables are discordant, when LAVi is normal despite suspected dysfunction, or when applying the AF or PH pathway. State the gating method and software where the value drives the conclusion. |
| Algorithm used | State when a special-population pathway was applied instead of the sinus rhythm algorithm |
| Comparison | Note any change from the previous study |
| Further assessment | Recommend diastolic exercise echocardiography where clinically appropriate |
What Changed in 2025
| Change | Practical effect |
|---|---|
| Diagnosis separated from LAP estimation | Figure 2 establishes whether diastolic dysfunction is present; Figure 3 estimates filling pressure and grade. Fixed e′ thresholds anchor both, with age-specific values as an optional refinement |
| Revised three-variable resting algorithm | e′, E/e′ and TR/PASP assessed simultaneously rather than sequentially |
| LA reservoir strain elevated to a core diagnostic marker | LARS ≤ 18% is now a Step 2 functional criterion for diagnosing diastolic dysfunction, a supplementary criterion for LAP estimation, and part of the dedicated AF and PH pathways |
| Dedicated phenotype pathways | Distinct algorithms for AF, moderate–severe MAC, pulmonary hypertension and transplantation |
| Closer integration with HFpEF | Explicit role for diastolic exercise echocardiography in symptomatic patients with normal or indeterminate resting findings |
| Reporting requirements strengthened | Grade and filling pressure both reported; indeterminate is an acceptable conclusion |
Frequently Asked Questions
Which e′ cut-offs should I use — fixed or age-specific?
The fixed thresholds — septal e′ ≤ 6, lateral e′ ≤ 7, or average e′ ≤ 6.5 cm/s — form the core of the 2025 algorithm and indicate abnormal relaxation irrespective of age. The age-specific values are an optional additional consideration when judging whether e′ is abnormally reduced. They matter most in younger patients: a 30-year-old with a septal e′ of 6.5 cm/s clears the fixed threshold, but sits well below the expected value for age (< 7 cm/s abnormal at 20–39 years), which may still be clinically meaningful.
How do you estimate left atrial pressure in atrial fibrillation?
Average measurements over at least five cycles and assess four variables: mitral E ≥ 100 cm/s, septal E/e′ > 11, TR velocity > 2.8 m/s or PASP > 35 mmHg, and deceleration time ≤ 160 ms. Three or more abnormal indicates elevated LAP; none or one indicates normal LAP. With exactly two abnormal, apply the secondary criteria — LARS < 18%, pulmonary vein S/D < 1 and BMI > 30 kg/m². The E/A ratio cannot be used, and LARS should not be used as a standalone marker.
When should diastolic stress echocardiography be performed?
Consider it in symptomatic patients with Grade 1 diastolic dysfunction, indeterminate resting filling pressure, or a high clinical suspicion of HFpEF despite an apparently normal resting study. A positive result requires an elevated average E/e′ (≥ 14) or septal E/e′ (≥ 15) together with a peak TR velocity ≥ 3.2 m/s, since E/e′ rises with exercise in normal subjects as well.
What is a normal LA reservoir strain?
Pooled normal LA reservoir strain in healthy adults is approximately 39%, with a lower limit of normal of 23% using R-wave gating. This is a different question from the 2025 diastolic algorithm's threshold of 18%, which is a higher-specificity decision point for elevated left atrial pressure. A value of 21% is therefore below the normal range but does not meet the algorithmic criterion for elevated filling pressure — report the number rather than a binary conclusion.
How do you distinguish constrictive pericarditis from restrictive cardiomyopathy?
The two most useful findings are respirophasic ventricular septal shift and the medial annular e′ velocity. Medial e′ above 7 cm/s despite heart failure — annulus paradoxus — favours constriction, while values below 5 cm/s favour restriction. Combined, these two steps give roughly 80% sensitivity and 96% specificity. Supporting features for constriction include annulus reversus, mitral inflow respiratory variation above 25%, and expiratory hepatic vein diastolic flow reversal. Normal pericardial thickness does not exclude constriction.
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