28. A non-transitory computer readable medium encoded with computer executable instructions for detecting and tracking coronary sinus (CS) catheter electrodes in a fluoroscopic image sequence, the computer executable instructions defining steps comprising: initializing a catheter electrode model in a first frame of a fluoroscopic image sequence based on input locations of a plurality of CS catheter electrodes in the first frame, wherein the catheter electrode model in the first frame comprises a plurality of template points corresponding to locations of the CS catheter electrodes in the first frame; and tracking the catheter electrode model in a second frame of the fluoroscopic image sequence by: detecting electrode position candidates in a second frame of the fluoroscopic image sequence using at least one trained electrode detector; generating catheter electrode model candidates in the second frame based on the detected electrode position candidates and the catheter electrode model initialized in the first frame by translating each of the plurality of template points of the catheter electrode model initialized in the first frame to each of the detected electrode position candidates in the second frame; calculating a probability score for each of the catheter electrode model candidates in the second frame; and selecting one of the catheter electrode model candidates in the second frame based on the probability score, wherein the selected catheter electrode model candidate provides locations of the plurality of CS catheter electrodes in the second frame.
28. A non-transitory computer readable medium encoded with computer executable instructions for detecting and tracking coronary sinus (CS) catheter electrodes in a fluoroscopic image sequence, the computer executable instructions defining steps comprising: initializing a catheter electrode model in a first frame of a fluoroscopic image sequence based on input locations of a plurality of CS catheter electrodes in the first frame, wherein the catheter electrode model in the first frame comprises a plurality of template points corresponding to locations of the CS catheter electrodes in the first frame; and tracking the catheter electrode model in a second frame of the fluoroscopic image sequence by: detecting electrode position candidates in a second frame of the fluoroscopic image sequence using at least one trained electrode detector; generating catheter electrode model candidates in the second frame based on the detected electrode position candidates and the catheter electrode model initialized in the first frame by translating each of the plurality of template points of the catheter electrode model initialized in the first frame to each of the detected electrode position candidates in the second frame; calculating a probability score for each of the catheter electrode model candidates in the second frame; and selecting one of the catheter electrode model candidates in the second frame based on the probability score, wherein the selected catheter electrode model candidate provides locations of the plurality of CS catheter electrodes in the second frame. 35. The non-transitory computer readable medium of claim 28 , wherein the computer executable instructions defining the step of selecting one of the catheter electrode model candidates in the second frame based on the probability score comprise computer executable instructions defining the steps of: selecting a number of catheter electrode model candidates in the second frame based on the probability scores calculated for the catheter electrode model candidates in the second frame; refining affine parameters of the selected catheter electrode model candidates in the second frame to locally maximize the probability scores; and selecting the catheter electrode model candidate in the second frame having the highest locally maximized probability score.