Atrial Fibrillation Arising from the Left Atrial Appendage.

A 63-year-old patient presented for curative treatment of drug-resistant paroxysmal atrial fibrillation (AF). After pulmonary vein antrum isolation was achieved, AF could be still induced and persisted, while rapid activation at the left atrial appendage was conducted to the left atrium in a decremental conduction manner. A step-wise incremental discrete radiofrequency energy application at the ostium of left atrial appendage completely eliminated the AF. Neither AF nor atrial tachyarrhythmias reappeared, even under isoproterenol infusion and vigorous rapid atrial stimulations. The patient has experienced no symptoms or exhibited ECG evidence of AF during a 6-month follow-up.