Type I Idiopathic Atrial Flutter: Ablation of the Tricuspid Annulus and Vena Cava Ostium Isthmus with Radiofrequency

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Abstract

Background Atrial flutter is a typical reentry arrhythmia and its circuit involves an isthmus of atrial tissue limited by the tricuspid annulus and the vena cava ostium (TA-IVC). The aim of this study was to verify the efficacy and safety of the creation of a barrier with radiofrequency (RF) in the TA-IVC isthmus.MethodsThirteen consecutive patients, eleven males, with ages ranging from 31 to 75 years, with paroxysmal (n: 11) or permanent (n: 2) type I atrial flutter (negative P waves in lead II, III and a VF) were submit-ted to RF ablation of TA-IVC isthmus. A deflect-able catheter with 4 mm size tip was introduced in to the right ventricle apex and pulled back to the inferior vena cava. When the atrial electrogram was detected, RF application was started (20 watts during 60 seconds) in the area next to the inferior vena cava ostium until atrial flutter was interrupted. Then, a vigorous atrial stimulation protocol, including isoproterenol infusion, was begun. The following day, patients were submitted to transesofageal stimulation with the same protocol. Results Atrial flutter was interrupted in all patients (100%) with 4 to 48 (mean 22.3 ± 17.3) applications. Eleven patients (88.8%) with one session; 2 patients (11.1%) with two sessions. The mean time needed to stop the atrial flutter with one application was 31.9 ±8.2 secs. There were no complications. All patients (100%) remain asymptomatic after a mean follow-up of 131.8±80.8 days. Two patients are using propranolol to control symptomatic atrial and ventricular ectopic beats.ConclusionsIn a short-term, RF ablation on the TA-IVC isthmus is efficient and safe to interrupt and prevent the re-induction and recurrence of type I atrial flutter.