A method and system of electroanatomical mapping comprises bringing a patients image such as a fluoroscopic image and intracardiac signals into a computer based mapping system. Electroanatomical mapping or superimposing of cardiac electrical activity on fluoroscopic image is provided by placing visual indicators on electrode pairs of various catheters including standard catheters and ablation catheter. Visual indicators are coupled or linked to underlying electric signals from those electrode pairs via software coding, whereby electrical activity sequence of the heart is provided and updated in real-time on fluoroscopic image. A combination of fluoroscopic image and CT or MRI may also be used. The mapping system further comprises various algorithms for aiding in cardiac mapping and ablation of cardiac arrhythmias.