Left Atrial Diastolic Dysfunction And Pulmonary Venous Hypertension In Atrial Fibrillation: Clinical, Hemodynamic And Echocardiographic Characteristics.

Abstract

Left ventricular diastolic dysfunction has been well described; diastolic abnormalities of the LA are less frequently recognized and poorly understood. The purpose of this study was to investigate the clinical, hemodynamic and echocardiographic features of left atrial (LA) diastolic dysfunction. Patients with atrial fibrillation (AF), severe LA enlargement, and pulmonary venous hypertension (PVH, Group 1) were compared to patients with pulmonary arterial hypertension (PAH), normal LA size and sinus rhythm (Group 2). All underwent right heart catheterization and transthoracic echo to evaluate hemodynamics and LA function. Mitral regurgitation was evaluated by transesophageal echocardiography. LA diastolic function was measured by comparing filling fraction, pulmonary venous flow and compliance. Right atrial, pulmonary artery systolic and mean pressures were similar. Mean wedge pressure were increased in Group 1, 20.8±2.6 versus 9.7±2.8 mm of Hg (p<0.0001). The most striking hemodynamic difference was large V wave in Group 1 without significant mitral regurgitation. LA filling fraction was abnormal in Group 1, 11.4%±8.5 compared to Group 2, 111.5%±44 (p<0.0001). LA compliance was 0.39±0.27 ml/m2/mmHg in Group 1 versus 6.8±4.54 ml/m2/mmHg in Group 2 (p=0.001). There was a strong negative correlation between the V wave and LA filling fraction (r= 0.756, p<0.001). The ratio of the height of the transmitral E wave divided by the S/D ratio (the LA diastolic dysfunction index) correlated very strongly with the V wave (r=0.907, p<0.001). LA diastolic dysfunction is present in some patients with long standing AF and PVH. LA diastolic dysfunction, in addition to left ventricular diastolic dysfunction, may contribute to the syndrome of heart failure with preserved left ventricular systolic function.