[Three-dimensional electroanatomic mapping in the electrophysiology lab: when, how and why? : A practical...

Three-dimensional electroanatomic mapping has become an integral part of modern invasive electrophysiology. It combines catheter localization, patient-specific cardiac anatomy, local electrograms, activation timing, voltage information, and ablation lesion documentation within a spatial working model. For early-career electrophysiologists, however, the interpretation of these maps can be challenging. This review provides a practical introduction to three-dimensional (3D) mapping for young electrophysiologists during their first steps in the electrophysiology laboratory. It addresses when 3D mapping is useful or necessary, how a map is created, what information can be derived from different map types, and which pitfalls should be avoided. The article summarizes technical principles and clinical applications of 3D electroanatomic mapping based on current expert consensus documents, review articles, and practical electrophysiological concepts. 3D mapping is particularly valuable in atrial fibrillation ablation, atypical atrial tachycardias, ventricular tachycardias, redo procedures, congenital or postsurgical anatomy, and low-fluoroscopy workflows. Activation maps help visualize the temporal sequence of electrical propagation, whereas voltage maps provide information on scar, low-voltage areas, and potential arrhythmogenic substrate. The quality of a map depends on stable rhythm, reliable temporal and spatial references, catheter contact, signal quality, adequate point density, and correct annotation. 3D mapping is a powerful tool for navigation, mechanism analysis, substrate characterization, and ablation documentation. Nevertheless, it does not replace electrophysiological reasoning. Every map must be interpreted critically and validated using intracardiac electrograms, surface ECG, anatomy, pacing maneuvers, and defined procedural endpoints.