Atrial size independently correlates with the development of paroxysmal atrial fibrillation in patients with sick sinus syndrome.

BACKGROUND Atrial fibrillation arises in 20-30% of patients with sick sinus syndrome, increasing the risk of systemic embolization and mortality. The aim of this study was to examine the clinical determinants of development of paroxysmal atrial fibrillation in sick sinus syndrome patients before implantation of a pacemaker. METHODS This case-control survey involved 144 patients (mean age ± SD age: 72 ± 9 years) in whom implantation of a transvenous permanent pacemaker was planned for sick sinus syndrome. Patients were classified into two groups, patients with (n = 71) and without (n = 73) a history of paroxysmal atrial fibrillation before implantation. Clinical characteristics and echocardiographic parameters were analyzed. RESULTS The peri-implant right atrial area and left atrial area were significantly larger in patients with, than those without, paroxysmal atrial fibrillation. Multiple logistic regression analysis identified that the size of the left atrial area independently correlated with the development of atrial fibrillation: each 1 cm2 increase in left atrial area corresponded to a 44% increase in risk (odds ratio = 1.44 [1.22, 1.71]; p < 0.001). CONCLUSIONS The left atrial size independently correlates with the development of paroxysmal atrial fibrillation in sick sinus syndrome patients before pacemaker implantation.