Electromorphological remodeling and fibrosis of the left atrium (LA) play important role in pathogenesis of atrial fibrillation (AF) and may predict poor catheter ablation (CA) outcome. LA fibrosis may be assessed invasively using electroanatomical mapping (EAM) during electrophysiological study. We have previously shown that the extent of LA fibrosis may be assessed non-invasively by specle tracking echocardiography (STE), however the effects of underlying cardiac rhythm (sinus or AF) on the accuracy of analysis have not yet been examined.
The aim was to assess the relationship between LA function derived from echocardiography (TTE) and LA fibrosis using EAM in patients with AF and sinus rhythm (SR).
Patients (pts) n=66 (64% males, mean age 56+/-10) with non-valvular AF treated with first CA were studied. LA volume using biplane area-length method was calculated. In STE global peak atrial longitudinal strain (PALS) was obtained by averaging values in all LA segments in 4- and 2-chamber views. E/E' and LA stiffness index - the ratio of E/E' to PALS were assessed.
The EAM of LA was build using Carto System before CA. Low amplitude potentials area (LAPA) was quantitatively analysed and expressed as a percentage of LA surface using the range 0.5-0.05 mV to detect potential sites of fibrosis.
48 (72%) pts were in SR, 18 (28%) pts in AF during the analysis. Pearson correlation analysis showed a significant correlation between LAPA and TTE parameters only in pts with SR not in AF subgroup (table).
Assessment of LA function by TTE with STE correlates well with the extent of LA fibrosis assessed by EAM only in SR. Thus, STE may be useful in non-invasive assessment of LA fibrosis and proper selection of candidates for CA in SR, but may not be applicable during AF rhythm. These preliminary findings warrant further examinations.