This is the second of a three-volume project aimed at providing unique case reports (20 cases per volume) of supraventricular and ventricular arrhythmias encountered in clinical practice. The book focuses on catheter ablation procedures of paroxysmal and persistent atrial fibrillation of atypical atrial flutters. The cases presented were performed using the CARTO electro-anatomical mapping system, providing a high number of images to better understand arrhythmia features. The cases are built around high-quality figures acquired during the patients’ hospitalization and relevant medical images, such as electrocardiograms, Holter ECGs, and MRI/CT scans. Short videoclips with activation maps of the atria or the ventricles during the studied arrhythmia complete the information provided. The chapters include questions and answers and key messages at the end of each case, making it an invaluable tool for cardiologists, clinical cardiac electrophysiologists, and interventionalcardiac electrophysiologists in training, as well as for anyone interested in learning more about the subject.