Left atrial electromechanical conduction time predicts atrial fibrillation in patients with mitral stenosis: a 5-year follow-up speckle-tracking echocardiography study.

Prolonged left atrial electromechanical conduction time is related with atrial electrical remodeling, and is predictive of the development of atrial fibrillation. The aim of our study was to examine whether left atrial electromechanical conduction time (EMT) and left atrial strain as measured by speckle tracking echocardiography (STE) are predictors for the development of atrial fibrillation (AF) in patients with mitral stenosis (MS) at 5-year follow-up. A total of 81 patients (61% females; mean age 38.1 ± 12.1 years) with mild or moderate MS of rheumatic origin according to ACC/AHA guidelines who were in sinus rhythm, and were asymptomatic or have NYHA class 1 symptom were included in the study. AF was searched by 12-lead electrocardiograms or 24-h Holter recordings during follow-up period. Atrial electromechanical conduction time (EMT), peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) were measured by STE. EMTs was defined as the interval between the onset of P-wave to the peak late diastolic longitudinal strain in the basal lateral and septal wall. During the follow-up period of 5 years (mean follow-up duration, 48.2 ± 13.3 months), 30 patients (37%) developed AF on standard 12-lead ECG or at their 24-h Holter recording. At follow-up, patients who developed AF were older than patients without AF (42.4 ± 11.3 vs. 35.6 ± 11.9, p = 0.014). Mitral valve area (MVA) (1.39 ± 0.14 vs. 1.48 ± 0.18, p = 0.03), PALS (13.4 ± 4.6 vs. 19 ± 5.2, p < 0.001) and PACS (6 ± 2.7 vs. 8.4 ± 3.8, p = 0.004), were lower in patients who developed AF than in patients who did not develop. However, EMTs-Septal (208.2 ± 28.4 vs. 180.2 ± 38, p = 0.001), and EMTs-Lateral (247.1 ± 27.6 vs. 213.3 ± 43.5, p < 0.001) were longer in patients with AF than in patients without. In multivariate Cox regression analysis, PALS and left atrial EMTs-Lateral were independent predictors for development of AF at follow-up. In patients with mitral stenosis, left atrial strain and electromechanical conduction time in the lateral wall during the long term follow-up period are predictive for the development of atrial fibrillation. Speckle tracking echocardiography is a basic and easily-implemented method based on left atrial parameters which may be helpful for early detection of atrial fibrillation in patients with mitral stenosis.