[Sixty four-slice computed tomography unmasked unexpected source of atrial arrythmias--a case report].

We describe a 23-year-old man with drug refractory, left atrial arrhythmias (paroxysmal atrial tachycardia, runs, pairs and single extra beats) in the area of remnant of left upper pulmonary vein ostium (in fact, this vein). The superior drained into vena innominata/vena cava superior. The patient underwent three unsuccessful catheter ablations in another center. Computed tomography scan of left atrium and pulmonary veins revealed this rare congenital anomaly. This information was crucial to perform successful ablation in the area of remnant and distinguish left atrial appendage from the remnant area. During 6 month follow-up the patient remained free of arrhythmia.