Radiofrequency catheter ablation in patients with atrial fibrillation

Brief Reportthis novel technique, as well as to caution against the risk of developing pulmonary veno-occlusive syndrome, observed in one patient submitted to radiofrequency catheter ablation.Case 1 -The first patient was a 36 year-old male who had presented with occasional episodes of paroxistic AF for the past ten years, and daily recurrences for the past two years.He had failed to respond to quinidine associated to digoxine, amiodarone, sotalol and subsequently propafenone associated to atenolol.After clinical and echocardiographic evaluation, no systemic or structural heart disease was documented.Rest ECG was normal, but ambulatory Holter monitoring displayed several episodes of non-sustained AF following atrial premature beats and frequent episodes of atrial tachycardia.In June, 1998, an EP study was undertaken under deep sedation with propofol, midazolam and fentanyl.Three catheters were inserted percutaneously into the right femoral artery.A decapolar catheter was positioned at the lateral wall of the right atrium.An octapolar catheter was inserted into the coronary sinus, and a quadripolar catheter with a 4 mm tip was inserted in the left atrium, through a transeptal approach (fig.1).An intravenous bolus of heparin (5000 IU) was given, followed by a 1000 UI/hr continuous infusion.AF was recorded in left atrial electrograms, whereas right atrium electrograms were organized and regular (fig.2).Three direct current shocks (200 J) were delivered in an attempt to restore sinus rhythm, but that was maintained for only a few seconds, with AF recurrence (fig.3).With the catheter positioned at the right inferior pulmonary vein, we observed that AF initiated after an atrial premature beat occurring earlier at that site when compared to the right atrial and coronary sinus signals.However, it did not precede peripheral P wave.The catheter was subsequently manipulated towards the left superior pulmonary vein (LSPV) ostium and another direct current 200 J shock delivered.After AF recurred, it could be observed that the atrial beat initiating the tachycardia was about 100 msec earlier at this site than the P wave preceding the tachycardia (fig.4).A