Diastology: Use E/e’ to Estimate Left Atrial Pressure

🧭 REBEL Rundown 📌 Key Points 🎯 POCUS diastology answers one ED question: Is left atrial pressure (LAP) elevated right now? (not “diagnose diastolic dysfunction”) 📈 E/e’ estimates LAP using mitral inflow E (PW Doppler) and annular e’ (TDI) from an apical 4-chamber view Interpretation: E/e’ ≥ 14 → likely elevated LAP (supports cardiogenic pulmonary edema); ≤ 8 → LAP likely normal; 8–14 → indeterminate ⚡ Fast + actionable: With a decent apical view, E and e’ can be captured in ~60 seconds to guide diuresis/afterload reduction vs non-cardiac pathways ⚠️ Use context: E/e’ performs best in reduced EF and can be confounded by MR/MS, tachycardia, and BiPAP/PEEP 📝 Introduction A formal echocardiographic diagnosis of diastolic dysfunction is multivariable, nuanced, and not an ED priority in most acute dyspnea cases. In the emergency setting, the bedside question that changes management is simpler: Is left atrial pressure (LAP) elevated right now? Elevated LAP is the physiologic substrate for cardiogenic pulmonary edema and the target for therapies like diuresis and afterload reduction . “POCUS diastology” is a focused ultrasound approach that helps you answer that question quickly—often faster than CXR, BNP, or a “CHF vs pneumonia” radiology impression. POCUS diastology ≠ chronic diagnosis. It’s a real-time estimate of filling pressure to guide acute resuscitation. 🩺 Case: Acute dyspnea with an unclear story A 72-year-old obese woman presents with severe dyspnea. EMS placed her on BiPAP for hypoxia. She’s uncomfortable, with bibasilar crackles and faint wheezing. Vitals: BP 166/98, HR 110, RR 22, SpO₂ 86%. Your differential is broad: Pneumonia? COPD exacerbation? Flash pulmonary edema? CXR: “Atypical pneumonia vs pulmonary edema” (not helpful) Labs: WBC 14.1, pBNP 320 (still not helpful) Your bedside ultrasound: The IVC is dilated → tempting to anchor on CHF But you pause: COPD on BiPAP can also dilate the IVC via increased intrathoracic pressure and RV loading. You obtain a cardiac view: EF looks normal → but that doesn’t rule out elevated filling pressures (hello HFpEF physiology) Does this settle it? Can we give this patient bronchodilators, steroids and antibiotics? 🎯 The goal of POCUS diastology You’re not trying to label the patient with “diastolic dysfunction.” You’re asking one resuscitation question: Is LAP elevated in this moment? If yes → cardiogenic pulmonary edema becomes much more likely and diuresis/afterload reduction moves up the priority list. If no → search hard for non-cardiogenic causes (COPD, pneumonia, PE, ARDS, etc.). 🧬 Pathophysiology Refresher Diastolic filling depends on: Intrinsic: LV relaxation, LV compliance, atrial contraction Extrinsic: pericardial pressure, RV function, intrathoracic pressure (BiPAP), volume status When the LV is stiff/noncompliant, blood backs up into the LA → LAP rises → pressure transmits to the pulmonary vasculature → pulmonary edema . This can happen even with normal EF . 🛰️ The POCUS method: E/e’ to estimate LAP To estimate LAP, you measure: E wave: early diastolic mitral inflow velocity (PW Doppler) e’ wave: early diastolic mitral annular tissue velocity (TDI) Then calculate: E/e’ = Mitral inflow (E) ÷ Mitral annular velocity (e’) This ratio is used as a noninvasive estimate of LV filling pressures and correlates with formal echocardiography-derived estimates. Example formula cited in echo literature: LAP ≈ (1.24 × E/e’) + 1.9 Important nuance (keep your wording tight): E/e’ can be used in both preserved and reduced EF, but performance is generally stronger in reduced EF . In normal EF, treat E/e’ as a high-value clue rather than a standalone verdict—especially in the intermediate zone. 😅 Spectral Doppler feels intimidating (so let’s make it practical) A lot of POCUS users avoid Doppler because it feels “advanced.” Here’s the reality: If you can obtain a decent apical 4-chamber , you can obtain E and e’. Once the view is good, capturing waveforms is straightforward. 🛠️ Step-by-step: How to get E and e’ in under 60 seconds Mitral inflow E wave (PW Doppler) 1. Obtain an apical 4-chamber view Best view: interventricular septum appears vertical 2. Place the sample gate at the mitral leaflet tips If view isn’t perfectly parallel with flow of blood, consider using Doppler angle correction. 3. Activate Pulse Wave Doppler 4. Freeze the tracing & Identify: E = early filling wave A = atrial contraction wave 5. Measure peak E velocity Take the average of 3 measurements to be more precise. Mitral e’ wave (Tissue Doppler) 1. From the same apical 4-chamber view, switch to TDI & place the gate at the septal mitral annulus 2. Identify e’ (early diastolic annular motion) To accommodate the inflow of blood, the annulus moves basally and away from the probe. The waveforms will always be negatively deflected 3. Measure peak e’ velocity Take the average of 3 measurements to be more precise. 🧾 Interpreting E/e’ (cutoffs) 🚑 Resus scenario: back to the bedside You obtain your images: E wave = 110 cm/s e’ = 5 cm/s E/e’ = 22 That strongly supports elevated LAP and therefore cardiogenic pulmonary edema physiology. Action: You prioritize IV diuresis (and consider afterload reduction as appropriate), while avoiding reflexive bronchodilators/steroids/antibiotics as your default path. Result: The patient’s breathing improves within 30 minutes—less diagnostic drift, fewer unnecessary meds, and potentially fewer intubations. 👉 FAQ What is E/e’ on ultrasound? E/e’ is the ratio of mitral inflow (E wave) to mitral annular tissue velocity (e’). It’s used to estimate LV filling pressures and left atrial pressure. What E/e’ value suggests elevated filling pressure? An E/e’ ≥ 14 supports elevated LAP; ≤ 8 suggests normal LAP; 8–14 is indeterminate and should be integrated with other findings. Can E/e’ be used with preserved EF (HFpEF)? Yes, but it’s generally less reliable than in reduced EF. In HFpEF, treat E/e’ as a strong clue—especially when very high—while integrating the full clinical picture. Why not just use BNP or CXR? BNP and CXR can be nonspecific or delayed. E/e’ targets physiology (filling pressure) at the bedside when it matters most. Why aren’t we talking about the E/A ratio? The E/A ratio can be misleading because of the phenomenon of pseudonormalization . In grade 2 diastolic dysfunction the E/A ratio reverts from abnormal to normal ; this can be a clinical trap. 🚨 Bottom Line POCUS diastology doesn’t diagnose chronic diastolic dysfunction —it estimates real-time LAP E/e’ ≥ 14 supports elevated LAP and cardiogenic pulmonary edema physiology E/e’ ≤ 8 makes elevated LAP less likely—pursue alternative causes of dyspnea With a decent apical view, E and e’ are obtainable fast The right call can be diuretics instead of antibiotics , and a better trajectory for your patient 🏁 Clinical Bottom Line When you suspect pulmonary edema, don’t stop at lung ultrasound or BNP. Reach for your apical view, capture E and e’, and ask the real question: Is the left atrial pressure elevated enough to flood the lungs? With POCUS diastology, you’ll have the answer in under 60 seconds. 📚 References Greenstein YY, Mayo PH. Evaluation of Left Ventricular Diastolic Function by the Intensivist. Chest . 2018;153(3):723-732.  PMID: 29113815 Del Rios et al.  Emergency physicians used average e’ (<9 cm/s) alone to assess for diastolic dysfunction. Compared to cardiology standard, agreement was 85.4% (κ = 0.74). Shows the feasibility of streamlined approaches in real ED practice. J Ultrasound Med. 2018 May;37(5):1237-1243 ASE/EACVI 2025 Guidelines – The most recent comprehensive guidance on echocardiographic assessment of diastolic function, re-emphasizing the centrality of E/e’ in estimating LAP. J Am Soc Echocardiogr. 2025 Apr;38(4):278-317 Post Peer Reviewed By: Marco Propersi, DO (X: @Marco_propersi ), Mark Ramzy, DO (X/IG: @MRamzyDO ), Jailyn Avilla, MD (Insta: @jailyn_avi) 👤 Guest Authors Joseph Felice MD FPD-AEMUS APD, Ultrasound Division Vassar Brothers Hospital Poughkeepsie, New York Neha Kumrah, DO PGY 1 Emergency Medicine Resident Vassar Brothers Hospital Poughkeepsie, New York Showing Slide 1 of 2 🔎 Your Deep-Dive Starts Here Diastology: Use E/e’ to Estimate Left Atrial Pressure POCUS diastology doesn’t diagnose chronic diastolic dysfunction—it estimates left atrial ... Procedures and Skills Read More REBEL Core Cast 28.0 – Conference Pearls Take Home Points  No palpable pulse does not equal no ... Resuscitation Read More REBEL Cast Episode 16: Home Treatment of VTE with Rivaroxaban & RV Dilation on Bedside Echo Welcome to the September 2015 REBELCast, where Swami, Matt, and I ... 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Diastology: Use E/e’ to Estimate Left Atrial Pressure is an episode from REBEL Cast by Salim R. Rezaie, MD.

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This episode was published on Mar 9, 2026.

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