ABSTRACT: Recent clinical trials have shown that targeting rotors and focal impulses (FIs) during atrial fibrillation (AF) ablation improves outcomes. This study evaluated whether a novel computational mapping algorithm (CMA) could identify FIs and rotors, and characterize rotors when incidental ablation resulted in rhythm changes. Three-dimensional (3D) left atrial electroanatomic maps were created from signals recorded from multipolar circular mapping catheters in 61 patients undergoing persistent AF ablation. Forty of 61acquired patient datasets were of adequate quality for analysis CMA, employing an AF pattern recognition algorithm, creating 3D panoramic AF maps identifying drivers of AF (FI and rotors) post procedure. Rotors were further classified as substrate (SBR) or non-substrate based (NSBR) on the basis of rotor stability, proximity to voltage transition zones and complex fractionated atrial electrograms (CFAEs). Incidentally ablated identified AF drivers, including SBRs and NSBRs, were evaluated for rhythm changes. A total of 172 drivers were identified in 40 patients (2.2 drivers/patient). Seventy percent were rotors (120/172) and 30% were FIs (52/172). Sixty-seven percent of rotors were classified as SBR vs 33% as NSBR. Incidental ablation of SBRs resulted in rhythm change 91% of the time versus only 24% of the time for NSBR (p<0.0001).