1. A computer implemented method for compensating cardiac and respiratory motion in atrial fibrillation ablation procedures, the method executed by a computer comprising the step of: (a) acquiring a series of first 2-D image frames using an imaging system; (b) simultaneously determining a position of a circumferential mapping (CFM) catheter and a coronary sinus (CS) catheter in two consecutive frames of the series of first 2-D image frames; (c) determining a distance between a virtual electrode on the CS catheter and a center of the CFM catheter for a first consecutive image frame of the two consecutive image frames, and for a second consecutive image frame of the two consecutive image frames; and (d) if an absolute difference of the distance for the first consecutive image frame and the distance for the second consecutive image frame is greater than a predetermined threshold, compensating for motion of the CFM catheter in another 2-D image, wherein determining a position of the coronary sinus (CS) catheter comprises: receiving a model of the CS catheter determined from a set of points extracted from a first image frame of the series of first 2-D image frames, wherein said CS catheter is modeled as a set of electrodes extending from a tip of the CS catheter to a first proximal electrode (FPE), and including a virtual electrode (VE) positioned at a first proximal location on the CS catheter; detecting the tip, electrodes, and body points of the CS catheter in each subsequent frame using trained classifiers; generating a set of hypothesis v t for locating the VE in each subsequent frame based on a location of the detected FPE; and determining a hypothesis {circumflex over (v)} t for locating the VE in each subsequent frame by maximizing a posterior probability P(v t |I 0,. .. , t ) of the hypotheses v t for the image frames I 0,. .. , t .