Fluoroscopic projections to show catheter locations. Right anterior oblique (RAO) and left anterior oblique (LAO) views are shown. The duodecapolar catheter seen in the LAO view has electrodes spanning from the coronary sinus (CS) to the right atrium (RA). The ablation catheter (ABL) is in the left superior pulmonary vein. HIS, hexapolar His-bundle recording catheter; and LAA, left atrial appendage circular mapping catheter.