Noninvasive Assessment of Left Ventricular End Diastolic Pressure

The assessment of Left Ventricular End-Diastolic Pressure (LVEDP) is a cornerstone of hemodynamic evaluation. While the gold standard remains cardiac catheterization, echocardiography provides a robust, noninvasive framework.

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1. The Standard Doppler Approach

The primary method for estimating LVEDP (or its surrogate, Pulmonary Capillary Wedge Pressure) involves evaluating the relationship between mitral inflow and myocardial relaxation.

The E/e’ Ratio

This is the most widely used index. It correlates the early diastolic mitral inflow velocity (E) with the early diastolic mitral annular velocity (e’).

• Normal: E/e’ < 8 (usually implies LVEDP < 12 mmHg)
• Elevated: E/e’ > 14 (highly suggestive of elevated LVEDP)
• Gray Zone: 9–13 (requires additional parameters)

Supplemental Parameters

When E/e’ is inconclusive, the following findings support elevated LVEDP:

• Left Atrial Volume Index (LAVI): > 34 mL/m².
• Peak TR Velocity: > 2.8 m/s (indicates elevated pulmonary artery systolic pressure).
• Mitral L-Wave: Presence of a mid-diastolic flow wave suggests significantly delayed relaxation and elevated filling pressures.

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2. Calculation-Based Methods (Valvular Regurgitation)

If significant valvular regurgitation is present, we can use the Bernoulli equation (4v²) to derive pressures at specific points in the cardiac cycle.

Aortic Regurgitation (AR) Jet

The end-diastolic velocity of the AR jet reflects the gradient between the aorta and the LV at the very end of diastole.

LVEDP = Diastolic BP – 4(end-diastolic velocity of AR jet)²

Mitral Regurgitation (MR) Jet

While the peak MR jet informs Systolic BP, the -ve dP/dt (rate of pressure fall) can indirectly suggest LV compliance, though it is less commonly used for a direct LVEDP number.

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3. Advanced Techniques

Left atrial reservoir strain

Left atrial reservoir strain has emerged as a sensitive marker. A reduction in LA reservoir strain often precedes changes in the E/e’ ratio and strongly correlates with rising LVEDP.

Lung Ultrasound (B-lines)

While not a direct measure of pressure, the presence of multiple B-lines (comet tails) indicates pulmonary congestion, providing clinical “bedside” evidence that LVEDP has exceeded the threshold for transudation.

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4. Clinical Caveats

It is important to remember that noninvasive markers can be “fooled” in specific scenarios:

• Mitral Annular Calcification (MAC): Renders e’ measurements inaccurate.
• Significant Mitral Regurgitation: Often results in a high E velocity regardless of LVEDP.
• Atrial Fibrillation: Variability in cycle length requires averaging multiple beats and relies more on the peak TR velocity and IVRT.

Parameter	Normal Filling Pressure	Elevated Filling Pressure
Average E/e’	< 8	> 14
LA Volume Index	≤ 34 mL/m2	> 34 mL/m2
TR Velocity	≤ 2.8 m/s	> 2.8 m/s
Septal e’	≥ 7 cm/s	< 7 cm/s