Background: To assess the incidence of paroxysmal atrial fibrillation (AF) in patients with atrial septal aneurysm (ASA) and the relationship between ASA morphology and the incidence of AF.
Methods: Among 12,941 patients evaluated echocardiographically, 88 (0.68%) were diagnosed with ASA [with 35 (39.8%) males and 53 (60.2%) females; mean age, 54.3 ± 14.4 years]. The morphology of the aneurysm and the atria was evaluated by echocardiography, P wave dispersion was evaluated by 12-lead electrocardiography (ECG) and the presence of AF was confirmed by 24-hour ambulatory ECG monitoring. ASA was diagnosed when the base of the aneurysm on echocardiography exceeded 15 mm and its protrusion exceeded 7.5 mm.
Results: Paroxysmal AF was documented in 15 (17.0%) patients with ASA. We showed that the presence of AF depended on the area of the aneurysm, with the latter positively correlating with the area of the left atrium. We further found a significant relationship between the presence of atrial arrhythmia and the dispersion of P wave duration (p < 0.005). The remaining characteristics, such as gender and age, embolic events, interatrial shunt and comorbidities showed no correlation with the occurrence of AF.
Conclusions: The occurrence of paroxysmal AF in patients with ASA depends on the area of the aneurysm and the increased area of the left atrium. Patients with ASA and paroxysmal AF display a significantly higher dispersion of sinus P wave duration versus patients with ASA but without paroxysmal AF. The presence of ASA structure oscillation, the direction of aneurismal protrusion and the presence of interatrial shunt do not significantly affect the incidence of AF. (Cardiol J 2007; 14: 580-584).