The relationship between epicardial adipose tissue and P wave and QT dispersions

OBJECTIVE
Epicardial adipose tissue (EAT) secretes various proinflammatory and atherogenic mediators that have several endocrine and paracrine effects on heart. This study investigated the influence of EAT on QT and P wave dispersions (QTd, PWd), as simple, non-invasive tools of proarrhythmia on surface ECG.

METHODS
This was a cross-sectional study and included 70 patients with normal coronary arteries who underwent 12-derivation electrocardiography, echocardiography and biochemical examinations in order for QTd, PWd, and EAT thickness to be measured..

RESULTS
Median EAT thickness was 4.1 mm. Correlation analyses revealed that EAT was significantly associated with age (r=0.412, p<0.001), weight (r=0.262, p=0.028), body mass index (r=0.396, p<0.001), left atrium diameter (r=0.518, p<0.001), fasting plasma glucose (r=0.245, p=0.041), maximum P wave duration (r=0.343, p=0.004), minimum P wave duration (r=0.275, p=0.021) and PWd (r=0.265, p=0.026). No relation was found between study parameters and QTd. However, P wave dispersion was significantly related to EAT thickness (r=0.265, p=0.026), left atrium diameter (r=0.483, p<0.001), and the triglyceride levels (r=0.267, p=0.028). Multiple linear regression analyses revealed left atrial diameter as the only independent predictor of PWd.

CONCLUSION
A significant association between EAT and PWd was demonstrated in the study. While EAT is related to both increased PWd and left atrial size, left atrial diameter seems to be more important than EAT for prediction of atrial fibrillation (AF) in patients with normal coronary arteries.