The association between left atrial stiffness and low-voltage areas of left atrium in patients with atrial fibrillation.

The low-voltage areas of left atrium (LA-LVA) have recently been of significant focus. However, very few studies have focused on the association between LA function and LA-LVA, and the mechanism of appearance of LA-LVA remains unclear. We investigated the marker for the existence of LA-LVA using automated 3-D mapping system. We studied 92 patients (75 males, 68 ± 9 years, 47 non-paroxysmal AF) who received CA for AF and 40 control patients without AF. Echocardiography was performed before the CA, and high-density voltage mapping during sinus rhythm after pulmonary isolation was performed in AF patients. LA-LVA was defined as < 0.5 mV, and LA stiffness index (LASI) was defined as the ratio of E/e' to LA peak strain. LA-LVA (LVA burden > 10%) was detected in 19/92 AF patients (21%). Patients with LA-LVA were associated with higher LASI (1.64 ± 1.70 vs. 0.61 ± 0.46, p < 0.0001), larger LA volume, non-paroxysmal AF, higher brain natriuretic peptide, structural heart disease, and older age. On multivariate analysis, LASI, LA volume, and age were independently associated with the existence of LA-LVA. Of these markers, the highest area under curve was obtained with LASI. The rate of high LASI (≥ 0.552) was highest in AF patients with LA-LVA. Moreover, the existence of LVA in anterior LA wall was associated with higher LASI. High LA stiffness index was associated with the presence of LA-LVA. The LA-LVA might be attributed to LA functional remodeling rather than LA anatomical remodeling.