Atrial electromechanical delay and left atrial mechanical functions in hemodialysis and peritoneal dialysis patients

Determinants of left intra-atrial electromechanical delay as evaluated by tissue Doppler imaging in candidates for coronary artery bypass graft surgery

OBJECTIVES

Inhomogeneity in the atrial conduction time is a predisposing factor for atrial fibrillation. The aim of our study was to determine the independent determinants of the left intra-atrial electromechanical delay (LIAEMD) as a marker of left atrial (LA) dyssynchrony in candidates for coronary artery bypass graft surgery (CABGS).

METHODS

This prospective cross-sectional study recruited 516 consecutive candidates for CABGS. Via the pulsed-wave tissue Doppler imaging modality in echocardiography, the times between the P wave and the peak of the a' wave at the septal and lateral mitral annuli were measured and the difference between these times was considered to be LIAEMD. Additionally, clinical and laboratory data on each patient were gathered. The odds ratio for an increased LIAEMD was calculated in patients with and without diabetes in univariate and multivariate analyses.

RESULTS

The multivariable analysis revealed that in the patients without diabetes, obesity, calcium-channel blocker usage, an increased maximal LA volume, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio were independently correlated with an increased likelihood of LIAEMD occurrence (P < .05).

CONCLUSIONS

In our study on CABGS candidates, in the patients without diabetes, obesity, an increased maximal LA volume, calcium-channel blocker usage, and a decreased lateral e'/a' ratio and in the diabetic patients, diuretic usage and a decreased lateral e'/a' ratio independently determined increased LIAEMD. The prevention or treatment of factors that are detrimental to the LA electromechanical function may be helpful for the preservation of the LA electromechanical integrity.

Evaluation of Atrial Electromechanical Delay to Predict Atrial Fibrillation in Hemodialysis Patients

Background and objective: Prevalence of atrial fibrillation is higher in hemodialysis patients as compared to the general population. Atrial electromechanical delay is known as a significant predictor of atrial fibrillation. In this study, we aimed to reveal the relationship between atrial electromechanical delay and attacks of atrial fibrillation. Materials and methods: The study included 77 hemodialysis patients over 18 years of age giving written consent to participate in the study. The patients were divided into two groups based on the results of 24-h Holter Electrocardiogram (Holter ECG) as the ones having attacks of atrial fibrillation and the others without any attack of atrial fibrillation. Standard echocardiographic measurements were taken from all patients. Additionally, atrial conduction times were measured by tissue Doppler technique and atrial electromechanical delays were calculated. Results: Intra- and interatrial electromechanical delay were found as significantly lengthened in the group of patients with attacks of atrial fibrillation (p = 0.03 and p < 0.001 respectively). The optimal cut-off time for interatrial electromechanical delay to predict atrial fibrillation was >21 ms with a specificity of 79.3% and a sensitivity of 73.7% (area under the curve 0.820; 95% confidence interval (CI), 0.716⁻0.898). In the multivariate logistic regression model, interatrial electromechanical delay (odds ratio = 1.230; 95% CI, 1.104⁻1.370; p < 0.001) and hypertension (odds ratio = 4.525; 95% CI, 1.042⁻19.651; p = 0.044) were also associated with atrial fibrillation after adjustment for variables found to be statistically significant in univariate analysis and correlated with interatrial electromechanical delay. Conclusions: Interatrial electromechanical delay is independently related with the attacks of atrial fibrillation detected on Holter ECG records in hemodialysis patients.