Abstract Purpose of review Contemporary ablation for complex arrhythmias raises several challenges for electroanatomic mapping. We examine how current and emerging systems may meet these challenges, and we outline major unmet needs. Recent findings The latest versions of the 3 major systems (Carto™, Ensite X™, and Rhythmia™) all construct near real-time maps of cardiac anatomy, which can be registered to tomographic images that integrate thousands of electrical points from high-resolution catheters to create activation maps, and display voltage, proprietary features, and ablation lesion locations. While these systems have improved procedural efficiency, it is less clear that they have improved ablation outcomes particularly for atrial fibrillation (AF), scar-related atrial flutter, ventricular tachycardia (VT), and fibrillation (VF). These remain urgent needs. Summary Cardiac electroanatomic mapping has reached a mature stage for supraventricular and many ventricular arrhythmias. Novel functional mapping systems have shown success in improving ablation outcomes for AF, VT, and VF in small patient series, but none in randomized trials of broad unselected patient cohorts.