Left atrial speckle tracking analysis in patients with mitral insufficiency and history of paroxysmal atrial fibrillation

The occurrence of atrial fibrillation (AF), especially in patients with mitral regurgitation (MR), is related to the degree of left atrial (LA) myopathy, remodeling and fibrosis, that are responsible of LA electrical inhomogeneity and abnormal conduction velocities. Speckle tracking echocardiography (STE) has recently enabled the quantification of longitudinal myocardial LA deformation dynamics. Our aim was to investigate by STE the effects of the occurrence of paroxysmal AF on LA myocardial deformation, in a population of patients with asymptomatic chronic MR. We compared two groups of a total of 197 patients with MR: 54 with history of paroxysmal AF and 143 with MR alone. Subgroups were created according to MR degree. Peak atrial longitudinal strain (PALS) was measured in all subjects. Values were obtained by averaging all segments (global PALS), measured in the 4-chamber and 2-chamber views. Compared to the mild MR group (46.1 +/- A 4.9%), global PALS was lower in moderate MR group (22.1 +/- A 5.8%) and further reduced in the severe MR group (13.9 +/- A 4.2%; overall P < 0.0001 by ANOVA, P < 0.05 for all pair-wise comparisons). Besides, in each MR group, patients with history of paroxysmal AF presented a global PALS significantly reduced (overall P < 0.0001 by ANOVA). After multivariate analysis, global PALS was significantly and independently associated with paroxysmal AF. STE enables noninvasive quantification of LA dysfunction due to MR and paroxysmal AF. MR have a major negative impact on LA function. In patients with MR, the history of paroxysmal AF is associated to a further impair of LA myocardial reservoir function.