LV Diastolic Function Grading — 2025 ASE Algorithm & LAP Estimation

Echo Reference — Diastolic Function & Haemodynamics

LV Diastolic Function

2025 ASE diastolic function grading and LAP estimation algorithms for sinus rhythm, atrial fibrillation, mitral annular calcification, pulmonary hypertension, and heart transplant recipients. Interactive step-by-step grading tool with special population guidance.

5 Algorithms Reference Tables Interactive Grading Tool

▾ Use the interactive grading tool

Primary Variables — Sinus Rhythm Algorithm

The 2025 ASE algorithm uses three primary variables to assess diastolic function and estimate left atrial pressure. The interactive tool below walks through the complete algorithm step by step.

Variable	Abnormal Threshold
1. Reduced e' velocity	Septal e' ≤ 6 cm/s, or lateral e' ≤ 7 cm/s, or average e' ≤ 6.5 cm/s *
2. Increased E/e' ratio	Septal E/e' ≥ 15, or lateral E/e' ≥ 13, or average E/e' ≥ 14
3. Increased TR velocity / PASP	TR velocity ≥ 2.8 m/s or PASP ≥ 35 mmHg

* Age-adjusted e' values: For annular e' velocity, age-adjusted lower limits of normal can be applied in place of the fixed values shown above.

Supplementary Criteria

Primary Supplementary	Threshold
Pulmonary vein S/D ratio	≤ 0.67
LA reservoir strain (LASr)	≤ 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%

Exclusions

Do not apply the sinus rhythm algorithm in: mitral annular calcification (MAC), moderate–severe mitral regurgitation, mitral stenosis, atrial fibrillation, LVAD, non-cardiac pulmonary hypertension, heart transplant recipients, or pericardial constriction. The interactive tool below automatically routes to the correct dedicated algorithm.

Interactive diastolic function grading tool

Select a clinical context below and the tool will guide you step by step through the correct 2025 ASE algorithm — sinus rhythm, AF, MAC, pulmonary hypertension, or heart transplant. Enter your echo measurements at each step and receive a graded result with the variables that drove the decision.

Interactive Diastolic Function Grading Tool

Select the clinical context and enter measurements step by step. The tool applies the correct 2025 ASE algorithm and guides you to the result.

Diastolic Function Grading Tool

Step-by-step guided assessment based on the 2025 ASE diastolic function update. Select the clinical context, enter measurements, and the tool walks you through the correct algorithm.

Indicators of Elevated LVFP in Special Populations

The following populations have specific indicators of elevated LV filling pressures.

Population	Key Indicators of Elevated LVFP
Sinus tachycardia	Predominant early filling with depressed EF; IVRT ≤ 70 ms (specific, 79%); average E/e' > 14. When E and A are fused, compensatory pause after premature beats can separate waves.
HCM	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 ratio > 2.5; IVRT < 50 ms.
Mitral stenosis	IVRT < 60 ms; mitral A peak velocity < 1.5 m/s; IVRT/T_E-e' ratio < 4.2.
Mitral regurgitation	IVRT < 60 ms; Ar–A ≥ 30 ms; IVRT/T_E-e' ratio < 5.6; average E/e' > 14 with depressed EF.
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.

Diastolic Dysfunction Grades — Summary

The four grades of diastolic function represent a spectrum from normal relaxation to severely elevated filling pressures. Each grade has a characteristic mitral inflow pattern, LAP status, and clinical significance.

Grade	Filling Pattern	E/A Pattern	LAP	Clinical Significance
Normal	Normal relaxation	E > A (young), E ≈ A (older)	Normal	Normal diastolic function. No elevation of filling pressures.
Grade 1	Impaired relaxation	E < A (E/A < 0.8)	Normal	Delayed relaxation with normal filling pressures. Very common with age and hypertension. Generally benign but may progress.
Grade 2	Pseudonormal	E > A (E/A 0.8–2.0)	Elevated (mild–moderate)	Looks normal on inflow but filling pressures are elevated. Requires supplementary variables (e', E/e', TR velocity) to unmask. Responds to preload reduction.
Grade 3	Restrictive	E >> A (E/A ≥ 2.0)	Elevated (marked)	Markedly elevated filling pressures with stiff, non-compliant ventricle. Associated with advanced heart failure, poor prognosis. May be reversible (Grade 3a) or fixed (Grade 3b) — test with Valsalva.

Grade 3a vs 3b: If the restrictive pattern reverses to a pseudonormal or impaired relaxation pattern with Valsalva manoeuvre (E/A decrease ≥ 50%), it is Grade 3a (reversible). If the pattern persists, it is Grade 3b (fixed/irreversible), which carries a worse prognosis.

Age-Adjusted e' Reference Values

Annular e' velocity declines with age. The fixed thresholds (septal ≤ 6, lateral ≤ 7 cm/s) used in the algorithm may be overly sensitive in older adults and insensitive in younger patients. These age-adjusted lower limits of normal can be applied as an alternative.

Age (years)	Septal e' (cm/s)	Lateral e' (cm/s)
16 – 20	≥ 12.1	≥ 14.9
21 – 40	≥ 10.2	≥ 12.2
41 – 60	≥ 7.4	≥ 9.2
> 60	≥ 5.7	≥ 7.2

Clinical application: An e' below the age-adjusted lower limit of normal is more specific for diastolic dysfunction than the fixed thresholds, particularly in patients aged 40–60 where septal e' of 7 cm/s would pass the fixed threshold (≤ 6) but fail the age-adjusted cutoff (≥ 7.4). Consider age-adjusted values in borderline cases.

Measurement Pitfalls in Diastolic Assessment

Diastolic function assessment depends on multiple Doppler measurements that are each susceptible to specific technical errors. Recognising these pitfalls is critical for accurate grading.

Measurement	Pitfall	Impact
Mitral e' (TDI)	Sample volume not at the annulus — placed too far into the myocardium or mitral leaflet	Underestimates or overestimates e' velocity. Must be placed at or within 1 cm of the annular insertion.
Mitral e' (TDI)	Annular calcification (MAC) distorting tissue motion	e' becomes unreliable in moderate–severe MAC. Use the dedicated MAC algorithm instead.
Mitral E velocity	Sample volume not at mitral leaflet tips	E velocity is maximal at the leaflet tips. Placement further into the LV or at the annulus underestimates E.
Mitral E/A	E and A wave fusion during tachycardia (HR > 100 bpm)	E/A ratio is uninterpretable when fused. Wait for a compensatory pause after a premature beat, or use DT and TDI instead.
Mitral E velocity	Significant mitral regurgitation increasing transmitral flow	E velocity is elevated by volume overload, not just increased LAP. E/A ratio and E/e' may overestimate diastolic dysfunction severity.
TR velocity	Incomplete TR envelope or non-parallel alignment	Underestimates peak TR velocity → underestimates PASP. Use multiple windows. Contrast may improve the signal.
TR velocity	Elevated TR in non-cardiac PH (e.g. COPD, PE)	TR velocity reflects pulmonary pressures, not necessarily LAP. Use the PH-specific algorithm, which avoids TR as a primary variable.
E/e' ratio	Using septal e' in the presence of septal wall motion abnormality or LBBB	Septal e' is unreliable when septal motion is abnormal. Use lateral e' or average E/e' in these patients.
LA volume	Foreshortened apical views or measuring at incorrect phase	LAVi must be measured at end-systole (maximum LA size, just before mitral valve opening). Foreshortening underestimates volume.
Respiratory variation	Not averaging measurements across multiple cardiac cycles	Respiratory variation affects all Doppler velocities. Average ≥ 3 cycles in sinus rhythm, ≥ 5 cycles in AF.

General principle: When individual variables are conflicting or borderline, the algorithm is designed to guide you to supplementary criteria — not force a grade. An "indeterminate" result is a valid and important outcome. Never force a diastolic grade when the data does not clearly support it.

Constriction versus Restriction

Differentiating constrictive pericarditis from restrictive cardiomyopathy is one of the most challenging diagnostic dilemmas in echocardiography. Both present with diastolic heart failure, elevated filling pressures, and preserved EF. The distinction is critical because constriction is surgically treatable while restriction is managed medically or with disease-specific therapy (e.g. tafamidis for ATTR amyloid).

Echocardiographic Differentiation

Parameter	Constriction	Restriction
Septal motion	Septal bounce / respirophasic shift (pathognomonic)	Normal or reduced motion
Mitral annular e' velocity	Normal or increased (annulus paradoxus)	Reduced (< 8 cm/s)
Medial e' vs lateral e'	Medial e' ≥ lateral e' (annulus reversus)	Lateral e' > medial e' (normal pattern)
Mitral inflow respiratory variation	> 25% (enhanced ventricular interdependence)	< 15% (typically minimal)
Hepatic vein expiratory diastolic reversal	Prominent expiratory diastolic reversal	Inspiratory diastolic reversal (or absent)
SVC / IVC	Dilated, no respiratory variation	Dilated, no respiratory variation
Pericardial thickening / effusion	Thickened pericardium (may not be visible on echo — CT/CMR more sensitive)	Normal pericardium. May have small effusion with amyloid.
Myocardial strain (GLS)	Relatively preserved GLS	Reduced GLS (especially basal segments in amyloid — apical sparing pattern)
Wall thickness	Normal	May be increased (amyloid, Fabry, haemochromatosis)

Key discriminators: The septal bounce (respirophasic ventricular interdependence) and the annulus paradoxus (preserved or elevated e' despite elevated filling pressures) are the two most reliable echocardiographic signs of constriction. The combination of septal bounce + medial e' ≥ 9 cm/s + mitral inflow E variation > 25% has sensitivity ~90% and specificity ~95% for constriction. However, mixed constrictive-restrictive physiology can occur (e.g. post-radiation), and CMR with late gadolinium enhancement is valuable for confirming pericardial thickening and excluding infiltrative cardiomyopathy.

Hepatic vein timing: The phase of diastolic reversal is critical. In constriction, diastolic reversal is most prominent during expiration (when ventricular interdependence shifts filling away from the left heart and increases right-sided pressures). In restriction, diastolic reversal (if present) is most prominent during inspiration. This single observation can be highly discriminating when technical quality is adequate.

Diagnostic Overlap & Additional Imaging

Echo alone may be inconclusive in up to 20% of cases, particularly in post-radiation patients who can develop both pericardial and myocardial disease simultaneously. When echo findings are equivocal, CMR is the next step — it provides direct visualisation of pericardial thickness (normal < 2 mm, constriction typically > 4 mm), late gadolinium enhancement patterns (subendocardial in amyloid, patchy mid-wall in other infiltrative diseases, pericardial enhancement in active pericarditis), and real-time cine assessment of septal motion and respiratory variation. Invasive haemodynamics with simultaneous LV/RV pressure recording remain the definitive test when non-invasive imaging is discordant.

References

Nagueh SF, et al. Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography. J Am Soc Echocardiogr. 2025;38(7):537–569.
Lang RM, et al. Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults. J Am Soc Echocardiogr. 2015;28:1–39.
Welch TD, et al. Echocardiographic Diagnosis of Constrictive Pericarditis: Mayo Clinic Criteria. Circ Cardiovasc Imaging. 2014;7(3):526–534.
Klein AL, et al. ASE Clinical Recommendations for Multimodality Cardiovascular Imaging of Patients with Pericardial Disease. J Am Soc Echocardiogr. 2013;26(9):965–1012.

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