Relationship of the Pulmonary Artery End-Diastolic Pressure to the Left Ventricular End-Diastolic and Mean Filling Pressures in Patients With and Without Left Ventricular Dysfunction

Abstract

The relationship of the left ventricular end-diastolic pressure (LVEDP) and the pulmonary arterial "wedge" mean pressure (PAWMP) to the pulmonary artery end-diastolic pressure (PAEDP) was investigated by cardiac catheterization in 71 subjects. Pressure records were obtained simultaneously or immediately consecutively. In 15 subjects with normal LV function (LVEDP, 4 to 12 mm Hg) PAEDP was within 3 mm Hg of LVEDP (r = 0.70, P < 0.01) and within 3 mm Hg of PAWMP (r = 0.69, P < 0.01) in every instance. In 56 patients with LV dysfunction (LVEDP, 12 to 55 mm Hg), PAEDP was lower than LVEDP in 42, equal to LVEDP in six, and higher than the LVEDP in eight, who were in atrial fibrillation or had increased pulmonary vascular resistance (PVR). PAEDP correlated closely with PAWMP (r = 0.92, P < 0.001). In 30 patients with LV dysfunction in sinus rhythm, an a wave was identified in the PA pressure tracing (PA a) prior to systole which coincided in time and magnitude to the PAW a wave and was considered to represent retrograde transmission of the left atrial contraction wave. The PA a pressure was within 5 mm Hg of the LVEDP (r = 0.94, P < 0.001) in all except four patients, two of whom had elevated PVR. Thus, in the presence of LV dysfunction and elevated LVEDP, PAEDP correlated well with PAWMP, but failed to represent LVEDP accurately, while PA a wave pressure closely reflected LVEDP except when PVR was markedly increased.