Effects of left ventricular systolic dysfunction on left atrial appendage and left atrial functions in patients with chronic nonvalvular atrial fibrillation

Abstract

Objective — It has been claimed that left ventricular (LV) systolic dysfunction impairs left atrial (LA) and left atrial appendage (LAA) functions. In this study, we compared the LA and LAA function parameters in patients with chronic nonvalvular atrial fibrillation (AF) with and without LV systolic dysfunction.Methods and results — The study population consisted of 28 patients with chronic nonvalvular AF.Group I consisted of 12 patients with LV systolic dysfunction (mean age: 61 ± 14 years; LV ejection fraction: 44 ± 6%), group II of 16 patients with normal LV systolic function (mean age: 52 ± 15 years; LV ejection fraction: 65 ± 3%). LV ejection fraction (EF) was measured by echocardiography utilizing bi-plane area length method.The following LA and LAA transoesophageal echocardiography parameters were obtained: 1) LA diameter, 2) LAA ejection velocity, 3) LAA filling velocity, 4) LAA ejection fraction, 5) pulmonary venous (PV) systolic velocity, 6) PV diastolic velocity, 7) PV systolic velocity/diastolic velocity ratio.The left atrium diameter was significantly larger in group I than in group II (4.7 ± 0.7 cm vs. 3.8 ± 0.6 cm, p < 0.05). The LAA ejection velocity and LAA ejection fraction were significantly lower in group I than in group II (22.6 ± 15.5 cm/s vs 37.5 ± 11.3 cm/s and 26.9 ± 20.8% vs. 41.3 ± 10.9%, p < 0.05 for both comparisons). The PV systolic velocity and PV systolic velocity/diastolic velocity ratio were significantly smaller in group I than in group II (26.2 ± 14.8 cm/s vs. 51.5 ± 22 cm/s and 0.7 ± 0.6 vs. 1.2 ± 0.5, p < 0.05 for both comparisons). Although decreased LAA filling and PV diastolic velocities were determined in group I, no significant difference existed between groups I and II.Thrombus and/or spontaneous echo contrast (SEC) in the LA and/or LAA were more frequent in group I (75% vs. 18%, p < 0.05).Conclusion — These results indicate that LV systolic dysfunction impairs various LA and LA function parameters and is associated with an increased frequency of SEC and/or LA thrombus in patients with chronic nonvalvular AF.