Figure 2. RFCA targets. Gated multi-detector row CT scans (endocardial view) obtained in a patient with paroxysmal atrial fibrillation in normal sinus rhythm during the study show the left side of the left atrium. One or more of the distal pulmonary veins (a) was the original target for RFCA. As the procedure has evolved, newer targets include the pulmonary vein ostia (b) and (as in this patient) the pulmonary vein inflow vestibule (c). LAA = orifice of the left atrial appendage, LI = left inferior pulmonary vein, LS = left superior pulmonary vein.