This issue of Cardiac Electrophysiology Clinics, guest edited by Mohammad Shenasa and Amin Al-Ahmad, will focus on Advances in Cardiac Mapping and Catheter Ablation. This is part one of a two-part issue and will include articles centered around Basic Concepts in Cardiac Mapping, Novel Mapping & Imaging Systems & Technologies, and Catheter and Energy Sources. Topics include, but are not limited to, Embryology of the Cardiac Conduction System Relevant to Cardiac Arrhythmias; Anatomical Consideration Relevant to Atrial and Ventricular Arrhythmias; Fundamentals of Cardiac Mapping; Novel Cardiac Mapping Systems; Non-invasive Mapping & ECGI in Atrial and Ventricular Arrhythmias; Optical Mapping; Omnipolar Mapping; Cardiac CT, MRI, and Fibrosis Quantification; High resolution mapping in patients with atrial and ventricular arrhythmias; Contact Force and Ablation Index; and New Catheter Balloons Including Radiofrequency.