A method for mapping a cardiac chamber includes sensing activation signals of intrinsic physiological activity with a plurality of electrodes disposed in or near the cardiac chamber, the activation signals including a near-field activation signal component and a far-field activation signal component, isolating R-wave events in the activation signals, generating a far-field activation template representative of the far-field activation signal component based on the R-wave events, and filtering the far-field activation template from the activation signals to identify the near-field activation signal components in the activation signals.
