Electromechanical delay detected by tissue Doppler echocardiography is associated with the frequency of attacks in patients with lone atrial fibrillation

Abstract

Background: Our main purpose in this study is to compare atrial (inter-atrial, intra-left atrial, intra-right atrial) electromechanical delays of patients with lone atrial fibrillation (LAF) with healthy individuals and examine the relationship of annual LAF attack frequency.

Methods: 32 entirely healthy individuals and 32 patients who have presented with tachycardia and complying with LAF criteria have been included in the study. The time passing from the beginning of the P wave on electrocardiography to the A' wave on tissue Doppler trace was accepted as the atrial conduction time (PA'). The PA' time difference between the mitral annulus of left ventricle (ML) and the tricuspid annulus of right ventricle (TL) was defined as inter-atrial electromechanical delay (IA-EMD), the PA' time difference between the ML and septal mitral annulus (MS) as intra-left electromechanical delay (ILeft-EMD), the PA' time difference between MS and the TL as intra-right electromechanical delay (IRight-EMD).

Results: ILeft-EMD (21.8 ± 9.1 vs. 14.1 ± 4.9, p < 0.001), IRight-EMD (9.3 ± 6.8 vs. 5.9 ± 4.9, p = 0.03) and IA-EMD times (24.7 ± 11.2 vs. 11.9 ± 7.1, p < 0.001) were significantly longer in LAF patients. In multivariate regression analysis, using a model including age, gender and left atrium (LA) volumes, ILeft-EMD times (OR 1.14, 95% CI 1.03-1.27,p = 0.012), IA-EMD times (OR 1.12, 95% CI 1.03-1.23, p = 0.007) and LA volumes (OR 1.18, 95% CI 1.05-1.32, p = 0.005) were independent predictors of LAF. In LAF group, the frequency of AF episodes was significantly correlated with ILeft-EMD (r = 0.90, p < 0.001) and IA-EMD times (r = 0.36, p < 0.004), whereas, IRight-EMD times and LA volumes were not correlated with recurrence rates.

Conclusions: ILeft-EMD and IA-EMD may increase in the early stages of atrial fibrillation even without the left atrial dilation and may be more valuable than left atrial area and volume in predicting atrial fibrillation.