Impact of the metabolic syndrome on atrial size in patients with new-onset atrial fibrillation.

Atrial fibrillation (AF) is the most common arrhythmia, and it is strongly related to atrial enlargement. Metabolic syndrome (MetSyn) is associated with increased cardiovascular morbility and mortality. However, the impact of the MetSyn on cardiac arrhythmias is poorly elucidated. The aim of this study was to compare atrial dimensions in patients suffering from nonvalvular paroxysmal AF, with and without MetSyn, trying to identify structural differences that could favor the occurrence of this arrhythmia. The study population consisted of 60 patients who presented with at least 1 episode of paroxysmal AF. From these, 26 patients fulfilled the criteria of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definition of MetSyn, while the remaining 34 patients did not. Left atrial size was assessed by 2-dimensional echocardiography. Patients with MetSyn had a mean atrial size of 46.2 -/+ 4.3 mm and those without MetSyn had a mean atrial size of 41.6 -/+ 1.9 mm, p < 0.011. MetSyn may favor the occurrence of paroxysmal AF by increasing atrial size. This concept deserves more research.