Atrial Fibrillation, the most common atrial sustained arrhythmia, is a result of multiple re-entrant wavelets in the atria, which conducts to its partial disorganization. Although it is not a lethal disease, it may lead to very disabling complications such as cardiac failure and atrial thrombosis, with the subsequent risk of a stroke. One of the characteristics of AF episodes is the absence of P waves before the QRS-T complex of the ECG, which are replaced by 'sawtooth'-like pattern waves along the cardiac cycle (see Figure 1). Additionally, these waves are associated with irregular cardiac frequency. During the last years, these two main characteristics of AF have been object of intense research for the detection and prediction of AF.