Right atrial compartmentalization using radiofrequency catheter ablation for management of patients with refractory atrial fibrillation

Ablation of Atrial Fibrillation. Introduction: Atrial fibrillation (AF) is often refractory to antiarrhythmic drugs, and patients who are intolerant o f AF may require the maze operation for cure. As a less invasive alternativ e, a catheter-based, right atrial compartmentalization procedure was evalua ted. Methods and Results: Twelve patients with AF refractory to Class I and III antiarrhythmic drugs were studied, Four linear right atrial radiofrequency ablations mere performed, from superior to inferior vena cava in the poster ior wall and interatrial septum, anteriorly from the superior vena cava to the tricuspid annulus through the appendage, and across the tricuspid valve -inferior vena cava isthmus, The radiofrequency catheter was dragged along each line three to four times, until the atrial electrogram amplitude decre ased by 75% and there mas bidirectional conduction block in the tricuspid v alve-inferior vena cava isthmus, One complication occurred: sinus node dysf unction requiring a pacemaker. Eight patients were discharged from the hosp ital on no antiarrhythmic drugs, and four mere discharged on previously ine ffective antiarrhythmic drugs. Total duration of follow-up was 21.3 +/- 11. 2 months. Four patients discharged on previously ineffective antiarrhythmic drugs had no recurrence of AF, One patient discharged off antiarrhythmic d rugs had no recurrence of AF, Seven patients discharged off antiarrhythmic drugs had recurrent AF by 12.6 +/- 13.0 months (median 6, range 1 to 39); 3 of these 7 responded to previously ineffective antiarrhythmic drugs withou t further AF and 4 did not. Thus, 8 of 12 patients (67%) had suppression of AF after ablation on previously ineffective medication or no medication. Conclusion: Right atrial compartmentalization may alter the substrate for A F, thus improving the efficacy of previously ineffective antiarrhythmic dru gs. Because it is relatively safe, it may be a reasonable adjunctive interv ention to maintain sinus rhythm in patients with drug-refractory AF.