We present the first 3 cases of atrial fibrillation treated by radiofrequency ablation in Costa Rica. They were males, 54, 55 and 50 years of age, the first had sinus node dysfunction and a normal structured heart, the second was hypertensive and the third had non-obstructive asymmetric septal hypertrophy. The left atrium measured 41, 48 and 47 mm respectively. Their presentation was one of paroxistic and repetitive arrhythmias, even under pharmacological treatment. We accessed the left atrium searching for pulmonary vein potentials, which indicate the presence of ectopic foci of activation, and radiofrequency was applied. In 2 cases we also documented atrial flutter that was successfully treated with ablation at the cavo-tricuspid isthmus. The patients tolerated the procedures well and they all are arrhythmia free 30 days after the intervention.

atrial fibrillation; flutter; ablation; radiofrequency; pulmonary vein potentials