In a patient with a normal left ventricular ejection fraction, what does an average E/e′ ratio of 5 indicate about left atrial filling pressures and diastolic function?

An average E/e' ratio of 5 indicates normal left atrial filling pressures and normal diastolic function in a patient with preserved ejection fraction.

An E/e' of 5 is well below the threshold of 14 used to identify elevated left atrial pressure (LAP), indicating that this patient has normal filling pressures. 1

Understanding the E/e' Ratio in Normal EF

The 2016 ASE/EACVI guidelines establish clear cutoff values for assessing left atrial pressure in patients with preserved left ventricular ejection fraction (LVEF):

• Average E/e' > 14: Indicates elevated LAP 1
• Average E/e' ≤ 14: Suggests normal or low LAP

With an E/e' of 5, this patient falls significantly below the threshold for elevated pressures, placing them in the normal range.

Clinical Interpretation Algorithm

In patients with normal LVEF, the assessment follows this structured approach 1:

Step 1: Evaluate the E/A ratio and peak E velocity

• If E/A ≤ 0.8 with peak E ≤ 50 cm/sec → Grade I diastolic dysfunction with normal/low LAP
• If E/A ≥ 2 → Grade III diastolic dysfunction with elevated LAP

Step 2: For intermediate E/A ratios (0.8-2), assess three key parameters:

• Average E/e' ratio (cutoff: >14)
• LA maximum volume index (cutoff: >34 mL/m²)
• TR jet velocity (cutoff: >2.8 m/sec)

Step 3: Determine LAP status:

• If ≥2 of 3 parameters exceed cutoffs → Elevated LAP (Grade II dysfunction)
• If ≤1 of 3 parameters exceed cutoffs → Normal LAP (Grade I dysfunction)

Your Patient's Status

With an E/e' of 5:

• This value is far below the pathologic threshold of 14
• It strongly suggests normal left ventricular filling pressures
• Unless other parameters (LA volume index or TR velocity) are markedly elevated, this patient likely has either normal diastolic function or Grade I diastolic dysfunction with normal filling pressures

Important Caveats

The E/e' ratio has limitations that you must recognize:

1. Gray zone exists (E/e' 8-14): Values in this range require additional parameters for accurate assessment 2. Your patient's value of 5 is well outside this gray zone.

2. Load dependency: Research shows E/e' can lose predictive capacity following acute load reduction 3, though this is more relevant for monitoring therapy than baseline assessment.

3. Better correlation in reduced EF: E/e' correlates more strongly with invasively measured pressures in patients with reduced EF (r=0.68) than preserved EF 3, but the guideline cutoffs remain valid.

4. Single parameter limitation: While E/e' alone has good specificity (93%) when >13 2, using multiple parameters increases diagnostic accuracy, particularly when E/e' falls in the 8-13 range.

Practical Application

For your patient with E/e' = 5:

• Document this as normal filling pressure on the echocardiographic report
• If clinical suspicion for heart failure exists despite this normal value, evaluate:
  • LA volume index (should be <34 mL/m²)
  • TR velocity (should be <2.8 m/sec)
  • Other clinical markers of volume overload

The combination of normal EF and E/e' of 5 makes elevated filling pressures highly unlikely, with specificity exceeding 90% 2, 4.