12 month embargo from publication ; Background and Objective: Optimal targets for persistent atrial fibrillation (persAF) ablation are still debated. Atrial regions hosting high dominant frequency (HDF) are believed to participate in the initiation and maintenance of persAF and hence are potential targets for ablation, while rotor ablation has shown promising initial results. Currently, no commercially available system offers the capability to automatically identify both these phenomena. This paper describes an integrated 3D software platform combining the mapping of both frequency spectrum and phase from atrial electrograms (AEGs) to help guide persAF ablation in clinical cardiac electrophysiological studies. Methods: 30 s of 2048 non-contact AEGs (EnSite Array, St. Jude Medical) were collected and analyzed per patient. After QRST removal, the AEGs were divided into 4 s windows with a 50% overlap. Fast Fourier transform was used for DF identification. HDF areas were identified as the maximum DF to 0.25 Hz below that, and their centers of gravity (CGs) were used to track their spatiotemporal movement. Spectral organization measurements were estimated. Hilbert transform was used to calculate instantaneous phase. Results: The system was successfully used to guide catheter ablation for 10 persAF patients. The mean processing time was 10.4 ± 1.5 min, which is adequate comparing to the normal electrophysiological (EP) procedure time (120~180 min). Conclusions: A customized software platform capable of measuring different forms of spatiotemporal AEG analysis was implemented and used in clinical environment to guide persAF ablation. The modular nature of the platform will help electrophysiological studies in understanding of the underlying AF mechanisms ; The research leading to these results was funded by the Leicester NIHR Cardiovascular Biomedical Research Unit, UK. Dr. Salinet has received research grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil, grant N. 200598/2009-0). Dr. Almeida has received research grants from CNPq (N. 200251/2012- 0) and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes). Dr. Vanheusden has received a research grant from NIHR Cardiovascular Biomedical Research Unit, UK and the Engineering and Physical Sciences Research Council (EPSRC). Dr. Chu has received a research grant from St. Jude Medical and honoraria 24 from Biosense Webster. Prof. Ng has received research fellowship from St. Jude Medical and speaker fees and honoraria from Biosense Webster. ; Peer-reviewed ; Post-print