Effects of cavotricuspid isthmus catheter ablation on paroxysmal atrial fibrillation

yIt has been demonstrated that successful cavotricuspid isthmus ablation of typical atrial flutter combined with atrial fibrillation (AF) sometimes in fluences the preablation history of paroxysmal AF. However, the effectivene ss of only isthmus ablation on AF itself is unclear. Endocardial catheter mapping during induced AF was performed around the tri cuspid annulus using duodecapolar electrode catheters in 39 patients with d rug-refractory paroxysmal AF. Isthmus ablation was performed in 16 patients (41%) in whom catheter mapping during AF showed an organized activation pa ttern around the tricuspid annulus. During a mean follow-up of 12.3 months, isthmus ablation was successful in preventing AF in 12(75%) patients, 8 without medication and 4 with a previo usly ineffective drug. This success group had a significantly higher F wave amplitude in lead V1 (0.29 +/- 0.10 vs 0.15 +/- 0.04 mV, p < 0.01), a high er left ventricular ejection fraction (74 <plus/minus> 9 vs 58 +/- 2%, p < 0.05), and a smaller left atrial dimension (35 <plus/minus> 6 vs 43 +/- 4mm . p < 0.05) than the failure group. Isthmus ablation mag be effective in preventing paroxysmal AF with an organ ized activation pattern around the tricuspid annulus. F wave amplitude, lef t ventricular ejection fraction, and left atrial dimension were significant predictors of success.