Atrial fibrillation (AF) is the most common arrhythmia among the general population. Its prevalence increases with advanced age but also with the presence of structural heart disease. In particular patients suffering from congestive heart failure (CHF) with low left ventricular (LV) ejection fraction present a significantly increased risk of developing AF and its detrimental hemodynamic effects, due to the loss of atrial contraction, and fast and irregular beats, are an even more relevant compared to patients without CHF.