Improved Interpretation of Pulmonary Artery Wedge Pressures through Left Atrial Volumetry-A Cardiac Magnetic Resonance Imaging Study.

In patients with LVEF < 50%, a normal PAWP did not reliably exclude LHD, and an elevated LVEDP was more frequent than an elevated PAWP. LAEF was the most relevant determinant of an increased PAWP, suggesting that a preserved LAEF in LHD may protect against backward failure into the lungs and the subsequent increase in pulmonary pressure.