Catheter ablation to terminate atrial fibrillation (AF), a most common cardiac arrhythmia has been shown to be successful for paroxysmal AF patients. However, limitations exist with inadequate cardiac mapping systems for persistent AF patients to identify active substrates outside the pulmonary vein region. Previously, Shannon Entropy (SE) based mapping approach was proposed to identify regions of high SE and to generate patient specific three-dimensional SE maps using current catheter mapping system. However, the exact location of the pivot point of the rotor has not been correctly identified using this approach. In this work, we present robust recurrence period density entropy (RPDE) based approach accurately identify pivot point of the rotors that were induced in ex-vivo isolated rabbit heart. Our results demonstrate the efficacy of the RPDE approach to precisely identify the pivot point of the rotor, and to provide a better contrast between the rotor core and the periphery region when compared to SE approach. The results motivate further application and validation of this technology using intra-atrial electrograms from paroxysmal and persistent AF patients aiming to accurately identify the location of the rotor pivot point.