Ablação com radiofreqüência do flutter atrial tipo I / Radiofrequency catheter ablation of type I atrial flutter

ABSTRACT

PURPOSE--To verify the efficacy and safety of the creation of a barrier with radiofrequency (RF) in the tricuspid annulus and the vena cava ostium (TA-IVC). METHODS--Nine consecutive patients, 7 males, with age ranging from 36 to 76 years, with paroxysmal (7 patients) or permanent (2) type I atrial flutter (negative P wave in lead II, III and F) were submitted to RF ablation of TA-IVC istmo. One deflectable catheter with 4mm size tip was introduced into the right ventricle apex and pulled back to the inferior vena cava. When the atrial electrogram was detected the RF application was started. The RF was applied (20 watts during 60s) up to the proximity of inferior vena cava ostium. The end point was to stop atrial flutter. Then a vigorous atrial stimulation protocol, including isoproterenol infusion was used. In the next day, patients were submitted to transesophageal stimulation with the same protocol. RESULTS--Atrial flutter was interrupted in all patients (100//) with 4 to 28 (mean 16.7 +/- 7.7) applications. Eight patients (88.8//) with one session and 1 (11.1//) with two sessions. The mean time spent to stop the atrial flutter with one application was 30.5 +/- 18.5s. There were no complications. After a mean follow up of 3 +/- 1.6 month all patients (100//) are asymptomatic. Two of them are taking propranolol to control symptomatic atrial and ventricular ectopic beats. CONCLUSION--RF ablation of the TA-IVC istmo is efficient and safe in a short term follow up to interrupt and prevent re-induction and recurrence of type I atrial flutter