By Felipe Andres Barona, ACS, RCS, RVS, RCCS, ARDMS (FE), ARRT (RT), CP-CC, BS

Introduction

It is not uncommon to hear the phrase, “The ejection fraction (EF) is normal, so the heart must be fine.” If that was truly the case, many of us could confidently retire our diagnostic curiosity. Yet, as every clinician knows, normal systolic function does not necessarily equate to normal cardiac function.

The concept of diastolic dysfunction often elicits a roomful of knowing nods, often without a clear understanding of the underlying physiology or assessment techniques. Rather than delving deeply into every grading nuance familiar to our cardiology colleagues, this discussion will focus on a practical, point-of-care approach. Our goal is to explore how the heart’s ability to relax (its diastolic function) is equally critical to its overall performance, and how estimating left atrial pressure can provide meaningful clinical insight.

We will review methods for assessing diastolic function using point-of-care echocardiography (POCUS-echo) and lung ultrasound, emphasizing a simplified, clinically relevant framework. To truly understand cardiac function, one must appreciate not only how forcefully the heart contracts, but also how effectively it relaxes between contractions.

Let us begin with lung ultrasound. The presence of diffuse bilateral B-lines is indicative of an alveolar interstitial pattern should prompt consideration of elevated left atrial pressure and evolving pulmonary edema. Recognizing these findings at the bedside provides valuable information about diastolic function and the patient’s hemodynamic status.

Understanding Diastology: A Simplified Overview for Clinicians

Diastology refers to the study and assessment of left ventricular (LV) relaxation and filling (diastolic phase of the cardiac cycle). Diastolic dysfunction develops when the left ventricle loses its ability to relax. In essence, the myocardium becomes stiff or noncompliant, leading to impaired ventricular filling at normal pressures.

As a result, left atrial (LA) pressure rises to maintain adequate LV filling. This elevation of LA pressure subsequently transmits backward into the pulmonary vasculature, contributing to pulmonary congestion or dyspnea in affected patients.

Echocardiography provides a non-invasive window into these hemodynamic changes. Parameters derived from Doppler and tissue Doppler imaging can estimate left atrial pressure (LAP), which closely reflects left ventricular end-diastolic pressure (LVEDP) and correlates with the mean pulmonary capillary wedge pressure (PCWP). Mastery of diastolic assessment is therefore essential for interpreting cardiac function comprehensively and guiding patient management.

The Evolving Understanding of Diastolic Dysfunction

Evaluating and grading diastolic dysfunction has long challenged echocardiographers. The 2009 guidelines from the American Society of Echocardiography (ASE) provided a rigorous framework, but their complexity often limited ease of application in daily clinical practice.

In 2025, the ASE and the European Association of Cardiovascular Imaging (EACVI) released an updated consensus designed to simplify assessment while maintaining diagnostic precision. This modern approach centers on four principal echocardiographic parameters:

1. Mitral inflow patterns (E/A ratio)
2. Tissue Doppler e′ velocity
3. E/e′ ratio (as a surrogate for left ventricular filling pressures)
4. Left atrial volume index
5. Tricuspid regurgitation velocity (to estimate pulmonary pressures)

While these measurements enhance diagnostic consistency, their integration into routine workflows, particularly for point-of-care ultrasound (POCUS) users and demands clinical pragmatism. At the bedside, the essential goal remains clear. Identify evidence of impaired relaxation and recognize elevated filling pressures without overcomplicating image acquisition or interpretation. In short, the emphasis is shifting from exhaustive parameter analysis toward pattern recognition and physiological understanding thus bringing diastolic assessment closer to real-world clinical utility.

Evaluating diastolic dysfunction plays a pivotal role in guiding fluid and volume management decisions, particularly in acutely ill patients. Although technical challenges can arise, especially in acquiring and interpreting Doppler measurements, clinicians can gain invaluable information when this assessment is integrated with lung ultrasound findings. Let us review some images below.

Figure 1. Transmitral flow echocardiography (Doppler) evaluates left ventricular (LV) diastolic function by measuring blood flow velocities across the mitral valve. It identifies the E-wave (early filling, 70–85% of flow – normal) and A-wave (atrial contraction, 15-20% of flow – normal). Normal hearts have a higher E-wave than A-wave (E/A ratio 1–1.5), while dysfunction alters this ratio. Image courtesy of Journal of American Society of Echocardiography July 2025

Figure 2. TDI – Mitral annulus

Figure 3. LAVi (mL/m2)

Figure 4. Peak TR vel (m/s)

Consider the following clinical cases

Case #1

A 58-year-old patient presents to the emergency department with shortness of breath and general malaise over the past several days. Point-of-care ultrasound (POCUS) is performed to assess cardiac function and pulmonary status. The echocardiographic findings reveal a left ventricular ejection fraction (EF) of approximately 50%. Doppler assessment demonstrates an E wave velocity of 81 cm/s, an A wave of 49 cm/s, and a septal e’ velocity of 10 cm/s. Concurrent lung ultrasound reveals diffuse bilateral B-lines.

Taken together, this POCUS profile suggests possible diastolic dysfunction with pulmonary congestion. The differential diagnosis includes cardiogenic pulmonary edema versus a primary inflammatory process. In such cases, integrating diastolic parameters and lung ultrasound findings provide critical context for determining fluid responsiveness and guiding early management decisions.

Case #2

A 68-year-old female, post-operative from cholecystectomy, develops new-onset shortness of breath and lower extremity edema. Lung ultrasound demonstrates diffuse, bilateral B-lines compatible with pulmonary edema. Focused cardiac ultrasound shows an estimated left ventricular ejection fraction of approximately 50%, which may be misinterpreted as “normal” systolic function in the setting of respiratory distress.

Echocardiographic findings show mitral inflow Doppler demonstrates an E wave of 91 cm/s and an A wave of 51 cm/s, yielding an E/A ratio >1, while tissue Doppler imaging reveals a markedly reduced e′ of 5 cm/s. The calculated E/e′ ratio is approximately 18 (91/5), which exceeds commonly accepted thresholds (≥13–14) for elevated left ventricular filling pressure and suggests increased left atrial pressure in the context of preserved EF.

These Doppler parameters are consistent with left ventricular diastolic dysfunction with elevated left atrial pressure, providing a unifying cardiac explanation for the pulmonary edema despite an apparently “normal” ejection fraction. In this perioperative context, the diffuse B-lines, leg edema, and elevated E/e′ ratio favor cardiogenic pulmonary edema over isolated ARDS, although mixed cardiogenic and noncardiogenic mechanisms can coexist in critically ill patients.

Recognition of diastolic dysfunction at the bedside has immediate therapeutic consequences, particularly regarding fluid management. In a patient with elevated LAP and pulmonary congestion, additional fluid resuscitation risks exacerbating pulmonary edema, whereas cautious diuresis and afterload/heart rate optimization are typically prioritized, with ongoing reassessment using POCUS and clinical parameters.

In postoperative dyspnea with bilateral B-lines, preserved EF alone is insufficient to exclude a cardiac cause; integration of mitral inflow, tissue Doppler e′, and E/e′ ratio allows estimation of left atrial pressure and helps distinguish cardiogenic pulmonary edema from primary lung injury such as ARDS at the point of care.

Did you know that evaluating left atrial (LA) pressure can be a key step in refining your differential diagnosis?

The Nagueh formula, widely used in echocardiography, provides a noninvasive method to estimate mean pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP), or left atrial pressure (LAP) using tissue Doppler imaging.

In its simplest form, the Nagueh formula relates the E/e′ ratio—where E represents the early diastolic trans-mitral flow velocity and e′ represents the early diastolic mitral annular velocity—to the left atrial pressure. An elevated E/e′ ratio generally reflects increased LAP, aiding the clinician in the assessment of left ventricular diastolic function and possible heart failure with preserved ejection fraction (HFpEF).

Assessing Left Atrial Pressure (LAP) Using POCUS Diastology

Accurate estimation of left atrial pressure (LAP) is integral to evaluating diastolic function and guiding management in patients with suspected heart failure or volume overload.

Normal LAP ranges:

• Normal: 6–12 mmHg
• Gray zone: 12–18 mmHg
• Elevated: >18 mmHg

Note: LAP values around 16 mmHg are generally considered mildly elevated and may indicate early left atrial (LA) dysfunction.

The Naguein formula (or equivalent simplified echocardiographic estimation) provides a rapid, clinically relevant correlation and supports timely therapeutic decisions at the bedside.

Step 1: Quick Assessment of Diastolic Function — E/A Ratio

The mitral inflow E/A ratio, readily obtained via pulsed-wave Doppler, remains a practical first step in point-of-care echocardiographic assessment of diastolic function:

In general, an E/A ratio < 0.8 is consistent with normal or low filling pressures, whereas an E/A ratio > 2.0 strongly suggests elevated LAP, often reflecting restrictive physiology.

Even in a focused POCUS evaluation, these straightforward diastolic parameters provide valuable clinical context—helping distinguish relaxation abnormalities from overt elevation in filling pressures without unnecessary complexity or panic.

Step 1 – Tissue Doppler (e’):

The tissue Doppler-derived early diastolic velocity (e’) reflects the rate of myocardial relaxation during diastole. A normal e’ velocity is typically ≥8 cm/s, indicating preserved diastolic relaxation. However, a key parameter to focus on is the E/e’ ratio, which provides a more comprehensive assessment of left ventricular filling pressures.

Step 2. Assessing the E/e′ Ratio

The E/e′ ratio provides an essential Doppler-based estimate of left ventricular filling pressures. An E/e′ value less than 8 suggests normal filling pressures, whereas a value greater than 14 indicates elevated left atrial pressure (LAP) and impaired diastolic relaxation.

When B-lines are present on lung ultrasound in conjunction with an elevated E/e′ ratio, the findings strongly support cardiogenic pulmonary edema. Conversely, B-lines with a normal E/e′ ratio are more consistent with noncardiogenic causes, such as infectious or inflammatory pulmonary processes.

Clinical Interpretation and Significance

Case #1

Transthoracic echocardiography demonstrates a left ventricular ejection fraction (EF) of 50% with diffuse bilateral B-lines on lung ultrasound, consistent with an interstitial-alveolar pattern suggestive of pulmonary congestion. Diastolic indices reveal an E wave velocity of 81 cm/s, A wave velocity of 49 cm/s, and tissue Doppler e′ velocity of 10 cm/s, yielding an E/A ratio of 1.8 and an E/e′ ratio of 8.

Using the simplified estimation formula for left atrial pressure (LAP = E/e′ + 4), the calculated LAP is approximately 12 mmHg, which lies at the upper limit of normal (reference range 6–12 mmHg). These findings indicate normal to mildly elevated left atrial pressures without clear evidence of significant diastolic dysfunction.

Given the bilateral B-lines in the context of a normal LAP, the patient’s pulmonary findings are less likely due to cardiogenic pulmonary edema and may instead reflect noncardiogenic causes such as infection or inflammation. Clinical correlation suggested community-acquired pneumonia, for which the patient—an adult male presenting to the emergency department—was appropriately managed with antibiotic therapy.

Let us review the findings again briefly:

EF 50%, diffuse bilateral B-Lines and LAP LAP= E/e’ + 4

E wave 81cm/s, A is 49cm/s, e’ 10cm/s. LAP= 8+4

E/A ratio =1.8 E/e’ =8 LAP=12

Normal LA pressures 6-12mmHg

So, the male patient coming through the ER will be treated with antibiotics after clinical correlation of pneumonia.

Case #2

A 68-year-old patient presented with respiratory distress. Echocardiographic assessment revealed a left ventricular ejection fraction (LVEF) of 50% and diffuse bilateral B-lines on lung ultrasound consistent with interstitial syndrome.

Doppler measurements demonstrated an early trans-mitral velocity (E) of 91 cm/s, late atrial velocity (A) of 51 cm/s, and mitral annular tissue velocity (e’) of 5 cm/s. The calculated E/A ratio was 1.7, with an E/e’ ratio of 16. Using the simplified estimation formula “LAP”=”E/e’”+4, the left atrial pressure (LAP) was approximately 20 mmHg, indicating elevated filling pressures.
The patient was managed with diuretic therapy, leading to resolution of B-lines on follow-up lung ultrasound and marked improvement in clinical symptoms and respiratory effort.

This case illustrates the complementary role of lung ultrasonography and Doppler-derived diastolic indices (particularly e’) in differentiating the etiology of acute respiratory failure. Values of E/e’ greater than 14 generally suggest elevated LAP and a cardiogenic origin (e.g., pulmonary edema), whereas values below 8 are more consistent with normal LAP and a non-cardiogenic process such as infection or inflammation. Clinical correlation remains essential, particularly in the intermediate range where overlap may occur.

Let us review the findings again briefly:

EF 50%, diffuse bilateral B-Lines and LAP LAP= E/e’ + 4

E wave 91cm/s, A is 51cm/s, e’ 5cm/s LAP= 16+4

E/A ratio =1.7 E/e’ =16 LAP=20

18mmHg or more elevated LAP

The 68 years old with increased LAP was treated with diuretics and lungs were clear and breathing improved.

Final Thoughts and Expert Advice

When you’re uncertain at the bedside, start simple. Begin with e’, then assess the left atrium. If myocardial relaxation velocity is reduced and the left atrium is enlarged, elevated filling pressures shouldn’t come as a surprise.

In a dyspneic patient, the combination of B-lines on lung ultrasound and a high E/e’ ratio usually points to elevated left-sided filling pressures, not pneumonia. At that moment, what you’re really seeing is pressure, not infection.

Keep your approach grounded in physiology—understanding before quantifying.

• A normal ejection fraction does not exclude heart failure.
• e’ reflects myocardial relaxation.
• E/e’ provides an estimate of filling pressure.
• Left atrial size signals the chronicity of elevated pressure.
• Physiology always matters more than memorizing cutoffs.

Think of the sequence simply:

A stiff ventricle → elevated filling pressure → pulmonary congestion.

Diastology is inherently dynamic—continuously shaped by volume status, blood pressure, and heart rate. In patients with atrial fibrillation or other arrhythmias, interpreting diastolic function can be especially challenging, often testing even the most experienced clinicians.

Remember, the heart does more than just contract/pump blood. It relaxes too. And sometimes… it simply refuses to relax.

Conclusion

Cardiac diastolic dysfunction centers on the intricate physiology of ventricular relaxation and filling pressures. If systole represents contraction and ejection, diastole embodies the heart’s ability to receive and accommodate blood. Impairment in this phase reflects the heart’s challenge in achieving effective relaxation.

Developing a solid command of diastolic assessment through echocardiography and point-of-care ultrasound (POCUS) equips clinicians with the insight to optimize fluid management and refine hemodynamic decision-making at the bedside. Understanding diastolic dysfunction doesn’t require overcomplication, just a clear perspective on how the heart fills when it’s supposed to rest.

Resources for Learning More About Diastolic Dysfunction

1. ASE Guidelines for Diastolic Function Assessment – https://www.asecho.org/wp-content/uploads/2025/07/Left-Ventricular-Diastolic-Function.pdf
2. EACVI Recommendations – https://www.asecho.org/guideline/left-ventricular-diastolic-function-by-echo/
3. https://westernsono.ca/wp-content/uploads/2019/12/Evaluation-of-Diastolic-Dysfunction.pdf
4. https://westernsono.ca/echo/

Call to Action

Are you interested in advancing your proficiency in cardiac point-of-care ultrasound (POCUS)?

Advance your expertise in cardiac ultrasound with the POCUS Certification Academy. Deepen your understanding of diastolic dysfunction, transforming uncertainty into diagnostic confidence because precise assessment of ventricular compliance requires well-trained clinicians.

Disclaimer* Figures 1, 2, 3,4 are courtesy of Journal of American Society of Echocardiography July 2025