The following are key points to remember about pulmonary arterial wedge pressure and left ventricular end-diastolic pressure for assessment of left-sided filling pressures:

1. The terms “pulmonary arterial wedge pressure” (PAWP) and “left ventricular end-diastolic pressure” (LVEDP) are often used interchangeably to describe left-sided filling pressures.
2. It should be noted that PAWP and LVEDP do not provide similar information, and the incorrect use of one term versus the other can lead to erroneous conclusions on the association of the left heart with patient symptoms and hemodynamic calculations, such as pulmonary arteriolar resistance.
3. The mean PAWP that integrates the atrial pressure tracing throughout systole and diastole provides an integrated measure of the hemodynamic burden imposed by the left atrial (LA) operating compliance (and indirectly LV operating compliance) on the pulmonary circulation.
4. In contrast, the LVEDP provides only information about the LV operating compliance. It measures the instantaneous pressure in the LV that distends the ventricle just prior to the onset of contraction that usually comes after atrial systole.
5. The discrepancies between LVEDP and mean PAWP are particularly exaggerated in the presence of a large V-wave (which increases the computer-integrated mean PAWP), as in mitral regurgitation, atrial fibrillation with poor atrial operating compliance, or stiff LA syndrome.
6. Uncommonly, mitral stenosis, pulmonary vein stenosis, or pulmonary veno-occlusive disease can also cause a higher PAWP than LVEDP.
7. Obtaining an accurate PAWP is especially important because this has been shown to have prognostic significance greater than that of the LVEDP in certain subgroups of patients by measuring the effect of LA and LV compliance on the pulmonary circulation.
8. The LVEDP is a surrogate measure of LV preload and LV diastolic operating compliance.
9. The mean PAWP, on the other hand, is a better reflection of the cumulative hemodynamic impact of ventriculoatrial coupling and its operating compliance on the pulmonary circulation.
10. When trying to calculate pulmonary arteriolar resistance or evaluate the cause of dyspnea that occurs on exertion, clinicians should preferentially use the mean PAWP instead of the LVEDP.

Keywords: Arrhythmias, Cardiac, Atrial Fibrillation, Atrial Pressure, Blood Pressure, Cardiac Surgical Procedures, Diastole, Dyspnea, Heart Failure, Hemodynamics, Heart Valve Diseases, Mitral Valve Insufficiency, Mitral Valve Stenosis, Physical Exertion, Pulmonary Circulation, Pulmonary Veno-Occlusive Disease, Pulmonary Wedge Pressure, Systole

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