Predictors of non-pulmonary vein ectopic beats initiating paroxysmal atrial fibrillation - Implication for catheter ablation

Non-pulmonary vein (PV) ectopic beats have been proven to initiate paroxysmal atrial fibrillation (PAF) in some patients, and the presence of non-PV ectopic beats might play an important role in the recurrence of PAF after PV isolation. This review article discusses the differential diagnosis, ablation strategy, anatomical substrate and clinical predictors in patients with non-PV ectopic beats initiating AF. In general, P wave morphology of surface ECG and intracardiac recordings are important in making an accurate diagnosis of non-PV AF. In clinical practice, left atrial enlargement could predict the presence of left atrial posterior free wall (LAPFW) ectopic beats initiating PAF; increased automaticity and increased trigger activity from the LAPFW might occur in patients with left atrial enlargement. Furthermore, female gender could predict the presence of superior vena cava (SVC) ectopic beats initiating AF; the gender difference in the incidence of SVC ectopic beats initiating PAF might be explained by the gender difference in female hormones and/or autonomic activities. Further studies are needed to define the exact effects of female hormones and autonomic tone on the SVC ectopic beats initiating PAF.